38AUQ
Heat Pump Condensing Units
60 Hz
with Puron® (R-410A) Refrigerant
Sizes 07, 08, and 12
Installation, Start-Up and
Service Instructions
Comfort Alert Diagnostic Module . . . . . . . . . . . . . . 28
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . 1
INSTALLATION GUIDELINES. . . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Step 1 – Plan for Unit Location . . . . . . . . . . . . . . . . . . . 7
Step 2 – Complete Pre-Installation Checks. . . . . . . . . . 7
Step 3 – Prepare Unit Mounting Support . . . . . . . . . . 7
Step 4 – Rig and Mount the Unit . . . . . . . . . . . . . . . . . . 7
Step 5 – Complete Refrigerant Piping Connections . . . 7
Step 6 – Install Accessories. . . . . . . . . . . . . . . . . . . . . . 10
Step 7 – Complete Electrical Connections . . . . . . . . . 10
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . 15
Preliminary Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
START-UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 -18
38AUQ Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
OPERATING SEQUENCE. . . . . . . . . . . . . . . . . . . . . . . . . . 19
Indoor (Supply) Fan. . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Cooling Unit Without Economizer. . . . . . . . . . . . . . . . . 19
Cooling, Unit With Economizer . . . . . . . . . . . . . . . . . . . 19
Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Supplemental Heating/Emergency Heating . . . . . . . . 19
Defrost Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Cooling and Heating Shutdown. . . . . . . . . . . . . . . . . 19
ROUTINE SYSTEM MAINTENANCE. . . . . . . . . . . . . . . 20
Quarterly Inspection (and 30 days after initial start). . 20
SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 - 31
Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . 20
Compressor Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Outdoor Coil Maintenance and Cleaning
Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Service Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . . 31
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
APPENDIX A
Air Conditioner and Heat Pump with Puron –
Quick Reference Guide. . . . . . . . . . . . . . . . . . . . . . . 33
APPENDIX B
Wiring Diagram List. . . . . . . . . . . . . . . . . . . . . . . . . 33
APPENDIX C
Motormaster Sensor Locations. . . . . . . . . . . . . . . . . 34
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . .CL-1, CL-2
®
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock
or other conditions which may cause personal injury or
property damage. Consult a qualified installer, service agency,
or your distributor or branch for information or assistance. The
qualified installer or agency must use factory-authorized kits or
accessories when modifying this product. Refer to the
individual instructions package
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloths for brazing operations and have a fire
extinguisher available. Read these instructions thoroughly and
follow all warnings or cautions attached to the unit. Consult
local building codes and appropriate national electrical codes
(in USA, ANSI/NFPA70, National Electrical Code (NEC); in
Canada, CSA C22.1) for special requirements.
It is important to recognize safety information. This is the
Servicing Systems on Roofs with
safety-alert symbol
. When you see this symbol on the unit
Synthetic Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
and in instructions or manuals, be alert to the potential for
personal injury.
Liquid Line Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . 21
Filed Refrigerant Access Ports . . . . . . . . . . . . . . . . . 21
Outdoor Coil Metering Devices. . . . . . . . . . . . . . . . . 21
Refrigerant System Pressure Access Ports . . . . . . . . 21
Heat Pump Controls. . . . . . . . . . . . . . . . . . . . . . . . . . 22
Commercial Defrost Board . . . . . . . . . . . . . . . . . . . . . . 22
Crankcase Heater. . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Compressor Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 22
Low-Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . 33
Understand the signal words DANGER, WARNING,
CAUTION, and NOTE. These words are used with the safety-
alert symbol. DANGER identifies the most serious hazards
which will result in severe personal injury or death.
WARNING signifies hazards which could result in personal
injury or death. CAUTION is used to identify unsafe practices,
which may result in minor personal injury or product and
property damage. NOTE is used to highlight suggestions
which will result in enhanced installation, reliability, or
operation.
Standard
Weight
Corner
A
Corner
B
Corner
C
Corner
D
Center of Gravity
Unit Height
UNIT
lbs.
kg.
lbs.
kg.
lbs.
kg.
lbs.
kg.
lbs.
kg.
X
Y
Z
H
23
26
13
42-3/8
38AUQ*07
444 201 134
61
97
44
90
85
41
123
125
157
56
[584]
[660]
[330]
[1076]
20
24
13
42-3/8
[1076]
38AUQ*08 483 219 162
38AUQ*12
74
84
110
126
50
57
39
48
57
71
[508]
[610]
[330]
21
24
23
50-3/8
575 261 186
106
[533]
[610]
[584]
[1280]
Fig. 1 — 38AUQ*07-12 Unit Dimensions
3
Table 1A — Physical Data — 38AUQ*07-12 Units — 60 Hz English
UNIT SIZE 38AUQ
*07
*08
*12
6
7.5
10
NOMINAL CAPACITY (tons)
OPERATING WEIGHTS (lb)
Aluminum-Fin Coils
444
483
R-410A
21.0
575
REFRIGERANT TYPE‡
Operating Charge, Typical (lb)†
18.0
10.0
27.0
15.0
Shipping Charge (lb)
12.0
COMPRESSOR
Qty...Type
1...Scroll
1...Scroll
1...Scroll
OUTDOOR FANS
Qty...Rpm
2...1100
2...1100
2...1100
1
1
1
Motor Hp
/
/
/
4
4
4
Diameter (in)
22
22
22
Nominal Airflow (Cfm Total)
Watts (Total)
6,000
610
6,000
610
6,000
610
1...Round Tube/Plate Fin (RTPF)
OUTDOOR COIL (Qty)
Face Area (sq ft total)
Rows/Fins per inch (FPI)
17.5
2/17
23.0
2/17
28.1
2/17
CONTROLS
Pressurestat Settings (psig)
High Cutout
Cut-in
630 ±10
505 ±20
27 ±3
630 ±10
505 ±20
27 ±3
630 ±10
505 ±20
27 ±3
Low Cutout
Cut-in
44 ±5
44 ±5
44 ±5
PIPING CONNECTIONS (in. ODS)
Qty...Vapor
1...11/8
1...3/8
1...11/8
1...1/2
1...13/8
1...1/2
Qty...Liquid
LEGEND
ODS — Outside Diameter Sweat (socket)
‡ Unit is factory-supplied with partial charge only.
† Typical operating charge with 25 ft of interconnecting piping.
4
Table 1B — Physical Data — 38AUQ*07-12 Units — 60 Hz SI
UNIT SIZE 38AUQ
*07
*08
*12
21.1
26.4
35.1
NOMINAL CAPACITY (kW)
OPERATING WEIGHT (kg)
Aluminum-Fin Coils
201
219
R-410A
9.5
261
REFRIGERANT TYPE‡
Operating Charge, Typical (kg)†
8.2
4.5
12.2
6.8
Shipping Charge (kg)
5.9
COMPRESSOR
Qty...Type
1...Scroll
1...Scroll
1...Scroll
CONDENSER FANS
Qty...r/s
2...18
2...18
2...18
1
1
1
Motor Hp NEMA
Diameter (mm)
Nominal Airflow (L/s)
Watts (Total)
/
/
/
4
4
4
560
2832
610
560
2832
610
560
2832
610
1...Round Tube/Plate Fin (RTPF)
CONDENSER COIL (Qty)
Face Area (sq m total)
1.6
2.1
2.6
Rows/Fins per Meter (Fins/m)
2/670
2/670
2/670
CONTROLS
Pressurestat Settings (kPa)
High Cutout
Cut-in
4344 ±70
4344 ±70
4344 ±70
3482 ±138 3482 ±138 3482 ±138
Low Cutout
Cut-in
186 ±21
303 ±35
186 ±21
303 ±35
186 ±21
303 ±35
PIPING CONNECTIONS (in. ODS)
Qty...Vapor
1...11/8
1...3/8
1...11/8
1...1/2
1...13/8
1...1/2
Qty...Liquid
LEGEND
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
‡ Unit is factory-supplied with partial charge only.
† Typical operating charge with 7.62 m of interconnecting piping.
5
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18
3
8 A U Q A 1 2 A 0
6
– 0 A 0 A 0
C
_____________
____
Model Type
Packaging
0 = Standard
1 = LTL
38AU= Carrier Condensing Unit
Puronr R---410A Refrigerant
Type of Coil
Q = Heat Pump Scroll Compressor
Electrical Options
A = None
C = Non-Fused Disconnect
Refrigerant Options
A = None
Service Options
B = Low Ambient
0 = None
1 = Un-powered Convenience Outlet
2 = Powered Convenience Outlet
Nominal Tonnage
07 = 6 Tons
08 = 7.5 Tons
12 = 10 Tons
Not Used
A = Place Holder
Not Used
Base Unit Controls
A = Not Used
0 = Electro-Mechanical Controls
Not Used
0 = Not Used
Design Revision
A = Initial Rev (Discrete Model Number)
Voltage
Coil Options
1 = 575/3/60
A= Al/Cu
B = Precoat Al/Cu
C = E-Coat Al/Cu
5 = 208/230/3/60
6 = 460/3/60
E= Cu/Cu
M= Al/Cu with Hail Guard
N = Precoat Al/Cu with Hail Guard
P = E-Coat Al/Cu with Hail Guard
R = Cu/Cu with Hail Guard
Fig. 2 — Model Number Nomenclature
POSITION NUMBER
TYPICAL
1
4
2
8
3
0
4
9
5
G
6
1
7
2
8
3
9
4
10
5
POSITION
1−2
DESIGNATES
Week of manufacture (fiscal calendar)
3−4
Year of manufacture (”09” = 2009)
5
Manufacturing location (G = ETP, Texas, USA)
Sequential number
6−10
Fig. 3 — Serial Number Nomenclature
6
CONSIDER SYSTEM REQUIREMENTS
.INSTALLATION
• Consult local building codes and National Electrical
Code (NEC, U.S.A.) for special installation requirements.
• Allow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig.1 for unit
dimensions and weight distribution data.
• Locate the unit so that the outdoor coil (condenser) air-
flow is unrestricted on all sides and above.
• The unit may be mounted on a level pad directly on the
base channels or mounted on raised pads at support
points. See Tables 1A and 1B for unit operating weights.
See Fig. 1 for weight distribution based on recommended
support points.
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National
Electrical Code) ANSI/NFPA 70 for special installation
requirements.
2. Determine unit location (from project plans) or select unit
location.
3. Check for possible overhead obstructions which may in-
terfere with unit lifting or rigging.
Step 1 — Plan for Unit Location
NOTE: If vibration isolators are required for a particular
installation, use the data in Fig. 1 to make the proper
selection.
Select a location for the unit and its support system (pad, rails
or other) that provides for the minimum clearances required for
safety. This includes the clearance to combustible surfaces, unit
performance and service access below, around and above unit
as specified in unit drawings. See Fig. 4.
Select a unit mounting system that provides adequate height to
allow for removal and disposal of frost and ice that will form
during the heating-defrost mode.
Step 3 — Prepare Unit Mounting Support
Slab Mount
Provide a level concrete slab that extends a minimum of 6 in.
(150 mm) beyond unit cabinet. Install a gravel apron in front of
condenser coil air inlet to prevent grass and foliage from
obstructing airflow.
NOTE: Consider also the effect of adjacent units on airflow
performance and control box safety clearance.
Step 4 — Rig and Mount the Unit
Do not install the outdoor unit in an area where fresh air supply
to the outdoor coil may be restricted or when recirculation from
the condenser fan discharge is possible. Do not locate the unit
in a well or next to high walls.
Evaluate the path and required line length for interconnecting
refrigeration piping, including suction riser requirements (out-
door unit above indoor unit), liquid line lift (outdoor unit below
indoor unit) and hot gas bypass line. Relocate sections to mini-
mize the length of interconnecting tubing.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
All panels must be in place when rigging. Unit is not
designed for handling by fork truck.
.
DO NOT BURY REFRIGERATION LINES.
RIGGING — These units are designed for overhead rigging.
Refer to the rigging label for preferred rigging method. Spread-
er bars are not required if top crating is left on the unit. All pan-
els must be in place when rigging. As further protection for coil
faces, plywood sheets may be placed against the sides of the
unit, behind cables. Run cables to a central suspension point so
that the angle from the horizontal is not less than 45 degrees.
Raise and set the unit down carefully.
If it is necessary to roll the unit into position, mount the unit on
longitudinal rails, using a minimum of 3 rollers. Apply force to
the rails, not the unit. If the unit is to be skidded into position,
place it on a large pad and drag it by the pad. Do not apply any
force to the unit.
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto the
unit.
RIGHT:
Min 18” (457 mm)
requried for service
REAR:
Min 18” (457 mm)
requried for service
LEFT:
Min 18” (457 mm)
FRONT:
requried for service
42” (1067 mm)
Raise from above to lift the unit from the rails or pad when unit
is in its final position.
After the unit is in position, remove all shipping materials and
top crating.
Note: Observe requirements for 39” (914 mm) operating clearance
on either Left or Rear coil opening.
Step 5 — Complete Refrigerant Piping
Connections
Refrigerant lines must be carefully designed and constructed to
ensure equipment reliability and efficiency. Line length, pres-
sure drop, compressor oil return, and vertical separation are
several of the design criteria that must be evaluated. See
Table 2.
Fig. 4 — Service Clearance Dimensional Drawing
Step 2 — Complete Pre-Installation Checks
CHECK UNIT ELECTRICAL CHARACTERISTIC —
Confirm before installation of unit that voltage, amperage and
circuit protection requirements listed on unit data plate agree
with power supply provided.
UNCRATE UNIT — Remove unit packaging except for the
top skid assembly, which should be left in place until after the
unit is rigged into its final location.
IMPORTANT: Do not bury refrigerant piping underground.
INSPECT SHIPMENT — File a claim with shipping com-
pany if the shipment is damaged or incomplete.
IMPORTANT: A refrigerant receiver is not provided with
the unit. Do not install a receiver.
7
Table 2 — 38AUQ*07-12 Piping Recommendations (Single-Circuit Unit)
Equivalent Length
R-410A
Model
Ft
0-38
38-75
75-113
113-150
Length Linear 0-25
Nominal Capacity Length Equiiv 0-38
25-50
38-75
50-75
75-113
75-100
113-115
3
3
3
1
3
1
38AUQ*07
38AUQ*08
38AUQ*12
Liquid Line
/
/
/
/
/
/
2
8
8
8
2
8
Max Lift
Cool
Heat
25
25
7
/
50
50
7
/
48
46
1-1/8
75
60
39
31
1-1/8
100
60
Suction Line
Charge (lbs)
Liquid Line
8
8
17.8
1
18.8
1
20.3
1
22.6
21.4
1
24.5
/
/
/
/
2
2
2
2
Max Lift
Cool
Heat
25
25
7
/
50
50
1-1/8
75
60
1-1/8
100
60
1-1/8
Suction Line
Charge (lbs)
Liquid Line
1-1/8
8
20.9
1
23.0
1
24.9
1
26.8
1
5
/
/
/
/
/
8
2
2
2
2
Max Lift
Cool
Heat
25
25
50
50
75
60
85
60
100
60
7
Suction Line
Charge (lbs)
/
1-1/8
1-1/8
1-1/8
1-1/8
1-3/8
8
26.8
28.8
30.7
33.4
37.2
Legend:
Length Equiv
Liquid Line
Equivalent tubing length, including effects of refrigeration specialties devices
Tubing size, inches OD.
Max Lift
Cooling
Heating
Maximum liquid lift at maximum permitted liquid line pressure drop
• Indoor unit ABOVE outdoor unit
• Indoor unit BELOW outdoor unit
Suction Line
Charge
Tube size, inches OD
Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger
suction line size (where applicable)
NOTE:
For applications with linear length greater than 100 ft (30.5 m), contact your local Carrier representative.
CHECK VERTICAL SEPARATION — If there is any vertical
separation between the indoor and outdoor units, check to
ensure that the separation is within allowable limits. Relocate
equipment if necessary.
PROVIDE SAFETY RELIEF — If local codes dictate an
additional safety relief device, purchase locally and install
locally. Installation will require the recovery of the factory
shipping charge before the factory tubing can be cut and the
supplemental relief device is installed.
REFRIGERANT LINE SIZING — Consider the length of
the piping required between the outdoor and indoor units. The
maximum allowable line length is 100 ft (30.5 m). See Table 2.
Refrigerant vapor piping should be insulated.
INSTALL FILTER
DRIER(S) AND
MOISTURE
INDICATOR(S) — Every unit MUST have a bi-directional
filter drier in the liquid line. Locate the filter drier at the indoor
unit, close to the evaporator coil’s thermal expansion valve
(TXV) inlets.
38AUQ units include one Puron-duty filter drier, shipped in
cartons attached to the unit basepan. Remove the filter drier
and prepare to install in the liquid line at the evaporator coil.
Do not remove connection fitting plugs until ready to connect
and braze the filter drier into the liquid line position.
Table 4 — Puron-duty Filter Drier(s)
Liquid
Desiccant
Volume
Part
Number Ref
Model-Size
Qty
Line OD
38AUQ*07
38AUQ*08
38AUQ*12
1
1
1
3/8-in
1/2-in
1/2-in
8 cu. in.
16 cu. in.
16 cu. in.
KH43LG091
KH43LG085
KH43LG085
IMPORTANT: A refrigerant receiver is not provided
with the unit. Do not install a receiver.
Table 3 — Maximum Vertical Separation*
Installation of liquid line moisture indicating sightglass in each
circuit is recommended. Locate the sightglass(es) between the
outlet of the filter drier and the TXV inlet.
Refer to Table 5 for recommendations on refrigeration
specialties.
Select the filter drier for maximum unit capacity and minimum
pressure drop. Complete the refrigerant piping from the indoor
unit to the outdoor unit before opening the liquid and suction
lines at the outdoor unit.
DISTANCE FT (M)
UNIT 38AUQ
UNIT 40RUQ
Unit 38AUQ
Above Unit 40RMQ
07
08
12
07
08
12
50 (15.2)
60 (18.3)
60 (18.3)
*Vertical distance between indoor and outdoor units.
8
Table 5 — Refrigerant Specialties Part Numbers.
LIQUID LINE
SIZE (in.)
LIQUID LINE
SOLENOID VALVE (LLSV)
LLSV
COIL
SIGHT
GLASS
FILTER
DRIER
3
/
/
/
ALC-066208
ALC-066209†
ALC-066212
AMG-24/50-60
AMG-24/50-60
AMG-24/50-60
HMI-1TT3
HMI-1TT4
HMI-1TT5
8
2
8
Provided with unit
See Table 4
1
5
†
38AUD units require TWO sets of parts.
INSTALL LIQUID LINE SOLENOID VALVE —
It is recommended that a bi-directional solenoid valve be
placed in the main liquid line (see Figs. 5 & 6) between the
outdoor unit and the indoor coil. Locate the solenoid valve at
the end of the liquid line, near the outdoor unit connections,
with flow direction arrow pointed at the outdoor unit. Refer to
Table 5. (A liquid line solenoid valve is required when the
liquid line length exceeds 75 ft [23 m].) This valve prevents
refrigerant migration (which causes oil dilution) to the
compressor during the off cycle, at low outdoor ambient
temperatures. Wire the solenoid according to the unit label
diagram.
EQUALIZER LINE
TXV
INDOOR
SENSING
BULB
COIL CKT 2
SIGHT GLASS
LOCATION
FILTER DRIER
LOCATION
TXV
AIRFLOW
15 DIAMS
CKT 2
10
MIN
DIAMS
8 DIAMS
MIN
TXV
SENSING
BULB
LIQUID
LINE
INDOOR
COIL CKT 1
SOLENOID
VALVE
TXV
AIRFLOW
15 DIAMS
MIN
CKT 1
10
DIAMS
8 DIAMS
MIN
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Failure to use a solenoid valve relay (SUR) accessory may
cause overload of Comfort Alert Diagnostic Module
(CADM) and compressor alarm lock out.
LEGEND
TXV — Thermostatic Expansion Valve
Fig.6 — Location of Sight Glass(es) and Filter Driers
(typical 38AUQ/40RUQ size 12 system)
CAPACITY CONTROL LIQUID LINE SOLENOID VALVE
Evaporator capacity control via liquid solenoid valve is not rec-
ommended for use with 38AUQ models.
Table 6 — Minimum Outdoor Air Operating Temperature
MINIMUM OUTDOOR
%
TEMP — F (C)*
EQUALIZER LINE
TXV
UNIT
COMPRESSOR
CAPACITY
Head Pressure
Control†
Standard Unit
INDOOR
SENSING
BULB
SIGHT GLASS
A LOCATION
COIL CKT
38AUQ07
38AUQ08
38AUQ12
35 (1.7)
35 (1.7)
35 (1.7)
–20 (–28.9)
–20 (–28.9)
–20 (–28.9)
FILTER DRIER
A
LOCATION
100
TXV
AIRFLOW
15 DIAMS
MIN
10
DIAMS
8 DIAMS
MIN
*Applies to Cooling mode of operation only.
LIQUID
LINE
†Wind baffles (field-supplied and field-installed) are recommended
for all units with low ambient head pressure control. Refer to Low
Ambient Control Installation Instructions (shipped with accessory)
for details.
SOLENOID
VALVE
LEGEND
TXV — Thermostatic Expansion Valve
Table 7 — Insulation for Vapor Line Exposed
to Outdoor Conditions
Fig.5 — Location of Sight Glass(es) and Filter Driers
(typical 38AUQ/40RUQ size 07 & 08 systems)
LENGTH OF EXPOSED
INSULATION THICKNESS†
VAPOR LINE*
ft
m
3
in.
mm
10
3
10
25
35
50
/
/
/
/
8
2
4
4
1
3
3
8
13
11
15
19
19
*Recommended vapor line insulation for piping exposed to outdoor
conditions to prevent loss of heating during heating cycle. When
vapor line goes through interior spaces, insulation should be
selected to prevent condensation on cooling cycle. Heating capac-
ity should be reduced 1000 Btuh (295 W) if over 35 ft (11 m) of
vapor line with 3/4 in. (19 mm) insulation is exposed to outdoor con-
ditions.
†Closed cell foam insulation with a thermal conductivity of: 0.28 Btu
• in./ft2 • h • °F (0.04 W/m • °C).
9
MAKE PIPING CONNECTIONS — Piping connections at
the 38AUQ unit are ball valves with stub tube extensions. Do
not open the unit service valves until all interconnecting tube
brazing as been completed.
The stub tube connections include ¼-in SAE service fittings
with Schrader valve cores (see Fig. 7). Before making any
brazed connections to the unit service valves, remove both
Schrader valve caps and cores and save for re-installation. Con-
nect a source for nitrogen to one of these service fittings during
tube brazing to prevent the formation of copper oxides inside
the tubes at brazed joints.
Example:
38AUQ*08
60-ft (18.3 m) linear line length
Equivalent line length 90-ft (27.4 m)
Liquid Lift: 20-ft (6.1 m)
Select line sizes from Table 2 (38AUQ):
1
Liquid / in
2
1
Suction 1- / in.
Charge 23.0 lbs (at 75-ft linear length)
8
80% of Operating Charge:
0.80 x 23.0 = 17.6 lbs
Field Service
Factory Shipping Charge: 12 lbs
Access Port
Factory
High-Flow
(Schrader core)
Field-charge quantity: 17.6 lbs –12.0 lbs = 5.6 lbs
Access Port
For linear line lengths longer than 100 ft (30.5 m), contact your
local Carrier representative for system charge value.
Service Valve
with Stem Cap
Sweat
Connection
Step 6 — Install Accessories
Accessories requiring modifications to unit wiring should be
completed now. These accessories may include Winter Start
controls, Low Ambient controls, phase monitor, Compressor
LOCout. Refer to the instructions shipped with the accessory.
Fig. 7 — Typical Piping Connection Assembly
When connecting the field tubing to the 38AUQ service valves,
wrap the valves in wet rags to prevent overheating
Pressure-test all joints from outdoor unit connections over to
the indoor coil, using nitrogen as pressure and with soap-and-
bubbles.
Step 7 — Complete Electrical Connections
When pressure-testing is completed, remove the nitrogen
source at the outdoor unit service valves and re-install the two
Schrader valve cores. Torque the cores to 2-3 in-lbs (23-34
N-cm).
Where vapor line is exposed to outdoor air, line must be
insulated. See Table 7 for insulation requirements.
EVACUATION/DEHYDRATION — Evacuate and dehydrate
the connected refrigeration system(s) (excluding the 38AUQ
unit) to 500 microns using a two-stage vacuum pump attached
to the service ports outside the 38AUQ service valves, follow-
ing description in GTAC II, Module 4, System Dehydration.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Do not use gas piping as an electrical ground. Unit cabinet
must have an uninterrupted, unbroken electrical ground to
minimize the possibility of personal injury if an electrical
fault should occur. This ground may consist of electrical
wire connected to unit ground lug in control compartment,
or conduit approved for electrical ground when installed in
accordance with NEC (National Electrical Code); ANSI/
NFPA 70, latest edition (in Canada, Canadian Electrical
Code CSA [Canadian Standards Association] C22.1), and
local electrical codes.
NOTE: Check all factory and field electrical connections
for tightness. Field-supplied wiring shall conform with the
limitations of 63°F (33°C) rise.
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
Puron® (R-410A) refrigerant systems operate at higher
pressures than standard R-22 systems. Do not use R-22
service equipment or components on Puron refrigerant
equipment.
Field Power Supply —
If equipped with optional Powered Convenience Outlet: The
power source leads to the convenience outlet's transformer pri-
mary are not factory connected. Installer must connect these
leads according to required operation of the convenience outlet.
If an always-energized convenience outlet operation is desired,
connect the source leads to the line side of the unit-mounted
disconnect. (Check with local codes to ensure this method is
acceptable in your area.) If a de-energize via unit disconnect
switch operation of the convenience outlet is desired, connect
the source leads to the load side of the unit disconnect. On a
unit without a unit-mounted disconnect, connect the source
leads to compressor contactor C and indoor fan contactor IFC
pressure lugs with unit field power leads.
All units except 208/230-v units are factory wired for the volt-
age shown on the nameplate. If the 208/230-v unit is to be con-
nected to a 208-v power supply, the control transformer must
be rewired by moving the black wire with the 1/4-in. female
spade connector from the 230-v connection and moving it to
the 208-v 1/4-in. male terminal on the primary side of the trans-
former. Refer to unit label diagram for additional information.
IMPORTANT: Charge in Cooling mode only!
PRELIMINARY CHARGE — Before starting the unit, charge
R-410A liquid refrigerant into the high side of each 38AUQ
circuit through the liquid service valve(s). The amount of
refrigerant added must be at least 80% of the operating charge
listed in Table 2 for LINEAR line length LESS the factory
charge quantity (if factory shipping charge has not been
removed). See the following example.
Allow high and low side pressures to equalize. If pressures do
not equalize readily, charge R-410A vapor (using special
service manifold with expansion device) into the suction line
service port for the low side of system to assure charge in the
evaporator. Refer to GTAC II, Module 5, Charging, Recover,
Recycling, and Reclamation for liquid charging procedures.
10
Field power wires are connected to the unit at line-side pres-
sure lugs on compressor contactor C and TB1 (see wiring dia-
gram label for control box component arrangement) or at facto-
ry-installed option non-fused disconnect switch. Max wire size
is #4 AWG (copper only).
Units Without Disconnect Option
C
TB1
11
13
NOTE: TEST LEADS - Unit may be equipped with short
leads (pigtails) on the field line connection points on con-
tactor C or optional disconnect switch. These leads are for
factory run-test purposes only; remove and discard before
connecting field power wires to unit connection points.
Make field power connections directly to line connection
pressure lugs only.
Disconnect
per
NEC
L1
L2
L3
208/230-3-60
460-3-60
575-3-60
Units With Disconnect Option
FIRE HAZARD
Failure to follow this warning could result in intermittent
operation or performance satisfaction.
Do not connect aluminum wire between disconnect switch
and condensing unit. Use only copper wire.
L1
2
1
Optional
Disconnect
Switch
Factory
Wiring
L2
L3
4
6
3
5
(See Fig. 8.)
Disconnect factory test leads; discard.
Fig. 9 — Power Wiring Connections
ELECTRIC
DISCONNECT
SWITCH
All field wiring must comply with the NEC and local
requirements.
COPPER
WIRE ONLY
Voltage and Current Balance -
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See Table 10.
On 3-phase units, voltages between phases must be balanced
within 2% and the current within 10%. Use the formula shown
in the legend for Table 8, Note 5 (see page 14) to determine the
percent of voltage imbalance. Operation on improper line
voltage or excessive phase imbalance constitutes abuse and
may cause damage to electrical components. Such operation
would invalidate any applicable Carrier warranty.
ALUMINUM
WIRE
Fig. 8 — Disconnect Switch and Unit
Units Without Factory-Installed Disconnect —
When installing units, provide a disconnect switch per NEC
(National Electrical Code) of adequate size. Disconnect sizing
data is provided on the unit informative plate. Locate on unit
cabinet or within sight of the unit per national or local codes.
Do not cover unit informative plate if mounting the disconnect
on the unit cabinet.
Convenience Outlets
Units with Factory-Installed Disconnect —
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Units with convenience outlet circuits may use multiple
disconnects. Check convenience outlet for power status
before opening unit for service. Locate its disconnect
switch, if appropriate, and open it. Tag-out this switch, if
necessary.
The factory-installed option disconnect switch is located in a
weatherproof enclosure located under the main control box.
The manual switch handle is accessible through an opening in
the access panel.
All units -
All field wiring must comply with NEC and all local codes.
Size wire based on MCA (Minimum Circuit Amps) on the unit
informative plate. See Fig. 9 for power wiring connections to
the unit power terminal block and equipment ground.
Maximum wire size is #4 ga AWG per pole.
Provide a ground-fault and short-circuit over-current protection
device (fuse or breaker) per NEC Article 440 (or local codes).
Refer to unit informative data plate for MOCP (Maximum
Over-current Protection) device size.
Two types of convenience outlets are offered on 38AUQ
models: Non-powered and unit-powered. Both types provide a
125-volt GFCI (ground-fault circuit-interrupter) duplex
receptacle rated at 15-A behind a hinged waterproof access
cover, located on the end panel of the unit. See Fig. 10.
11
Convenience
Outlet
GFCI
Pwd-CO
Fuse
Switch
Pwd-CO
Transformer
UNIT
VOLTAGE
CONNECT
AS
PRIMARY
CONNECTIONS
L1: RED + YEL
L2: BLU + GRA
TRANSFORMER
TERMINALS
H1 + H3
208,
230
240
H2 + H4
L1: RED
Splice BLU +
YEL
H1
H2 + H3
H4
460
575
480
Control Box
Access Panel
L2: GRA
L1: RED
L2: GRA
H1
H2
600
UNIT
VOLTAGE
CONNECT
AS
PRIMARY
CONNECTIONS
TRANSFORMER
TERMINALS
Fig. 10 — Convenience Outlet Location
Non-powered type: This type requires the field installation of
a general-purpose 125-volt 15-A circuit powered from a source
elsewhere in the building. Observe national and local codes
when selecting wire size, fuse or breaker requirements and
disconnect switch size and location. Route 125-v power supply
conductors into the bottom of the utility box containing the
duplex receptacle.
208,
230
L1: RED + YEL
L2: BLU + GRA
H1 + H3
H2 + H4
240
L1: RED
Splice BLU +
YEL
H1
H2 + H3
H4
460
575
480
L2: GRA
L1: RED
L2: GRA
H1
H2
600
Unit-powered type: A unit-mounted transformer is factory-
installed to stepdown the main power supply voltage to the unit
to 115-v at the duplex receptacle. This option also includes a
manual switch with fuse, located in a utility box and mounted
on a bracket behind the convenience outlet; access is through
the unit's control box access panel. See Fig. 10.
The primary leads to the convenience outlet transformer are not
factory-connected. Selection of primary power source is a
customer-option. If local codes permit, the transformer primary
leads can be connected at the line-side terminals on the unit-
mounted non-fused disconnect or HACR breaker switch; this
will provide service power to the unit when the unit disconnect
switch or HACR switch is open. Other connection methods
will result in the convenience outlet circuit being de-energized
when the unit disconnect or HACR switch is open. See Fig. 11.
Fig. 11 - Powered Convenience Outlet Wiring
Duty Cycle: the unit-powered convenience outlet has a duty
cycle limitation. The transformer is intended to provide power
on an intermittent basis for service tools, lamps, etc; it is not
intended to provide 15-amps loading for continuous duty loads
(such as electric heaters for overnight use). Observe a 50%
limit on circuit loading above 8-amps (i.e., limit loads
exceeding 8-amps to 30 minutes of operation every hour).
Test the GFCI receptacle by pressing the TEST button on the
face of the receptacle to trip and open the receptacle. Check for
proper grounding wires and power line phasing if the GFCI re-
ceptacle does not trip as required. Press the RESET button to
clear the tripped condition.
Fuse on power type: The factory fuse is a Bussman “Fusetron”
T-15, non-renewable screw-in (Edison base) type plug fuse.
Using unit-mounted convenience outlets: Units with unit-
mounded convenience outlet circuits will often require that two
disconnects be opened to de-energize all power to the unit.
Treat all units as electrically energized until the convenience
outlet power is also checked and de-energization is confirmed.
Observe National Electrical Code Article 210, Branch Circuits,
for use of convenience outlets.
Installing Weatherproof Cover
A weatherproof while-in-use cover for the factory-installed
convenience outlets is now required by UL standards. This
cover cannot be factory-mounted due its depth; it must be
installed at unit installation. For shipment, the convenience
outlet is covered with a blank cover plate.
The weatherproof cover kit is shipped in the unit's control box.
The kit includes the hinged cover, a backing plate and gasket.
DISCONNECT ALL POWER TO UNIT AND
CONVENIENCE OUTLET.
Remove the blank cover plate at the convenience outlet;
discard the blank cover.
Loosen the two screws at the GFCI duplex outlet, until
1
approximately / -in (13 mm) under screw heads are exposed.
2
12
Press the gasket over the screw heads. Slip the backing plate
over the screw heads at the keyhole slots and align with the
gasket; tighten the two screws until snug (do not over-tighten).
Mount the weatherproof cover to the backing plate as shown in
Fig. 12. Remove two slot fillers in the bottom of the cover to
permit service tool cords to exit the cover. Check for full
closing and latching.
Thermostat —
Install a Carrier-approved accessory thermostat according to
installation instructions included with the accessory. For
complete economizer function, select a two—stage cooling
thermostat. Locate the thermostat accessory on a solid wall in
the conditioned space to sense average temperature in
accordance with the thermostat installation instructions.
If the thermostat contains a logic circuit requiring 24-v power,
use a thermostat cable or equivalent single leads of different
colors with minimum of five leads. If the thermostat does not
require a 24-v source (no “C” connection required), use a
thermostat cable or equivalent with minimum of four leads.
Check the thermostat installation instructions for additional
features which might require additional conductors in the
cable.
COVER – WHILE-IN-USE
RECEPTACLE
WEATHERPROOF
NOT INCLUDED
For wire runs up to 50 ft. (15 m), use no. 18 AWG (American
Wire Gage) insulated wire (35°C minimum). For 50 to 75 ft.
(15 to 23 m), use no. 16 AWG insulated wire (35°C minimum).
For over 75 ft. (23 m), use no. 14 AWG insulated wire (35°C
minimum). All wire sizes larger than no. 18 AWG cannot be
directly connected to the thermostat and will require a junction
box and splice at the thermostat.
PremierLink (accessory installation) – Refer to Form 33CS-
58SI for details on connecting the PremierLink controller and
its various sensors.
BASE PLATE FOR
GFCI RECEPTACLE
Fig. 12 — Weatherproof Cover Installation
All Units —
R
G
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See Table 8.
On 3-phase units, voltages between phases must be balanced
within 2% and the current within 10%. Use the formula shown
in the legend for Table 8, Note 5 (see pages 14) to determine
the percent of voltage imbalance. Operation on improper line
voltage or excessive phase imbalance constitutes abuse and
may cause damage to electrical components. Such operation
would invalidate any applicable Carrier warranty.
Y1
O/B/Y2
(Notes 1, 2)
W1
Field Control Wiring —
38AUQ unit control voltage is 24 v. See Fig. 19 for typical
field control connections and the unit’s label diagram for field-
supplied wiring details. Route control wires to the 38AUQ unit
through the opening in unit’s end panel to the connections
terminal board in the unit’s control box.
W2
(Note 4)
C
(Note 3)
Remainder of the system controls connection will vary
according to the specific construction details of the indoor
section. Fig. 13 depicts typical connections to a Carrier 40RUQ
fan coil unit. Plan for field connections carefully and install
control wiring correctly per the project plan. Additional
components and supplemental transformer accessory may be
required.
The 38AUQ unit requires an external temperature control
device. This device can be a thermostat (field-supplied) or a
PremierLink controller (available as a field-installed accessory,
for use on a Carrier Comfort Network or as a stand alone
control).
Note 1: Typical multi-function marking. Follow manufacturer’s configuration
instructions to select Y2.
Note 2: Y2 to economizer required on single-stage cooling units when
integrated economizer function is desired
Note 3: Connect only if thermostat requires 24-vac power source.
Note 4: Connect W2 if supplemental heater installed
Field Wiring
Fig. 13 — Typical Remote Thermostat Connections
13
Table 8 — Electrical Data — 38AUQ*07-12 60 Hz Units
NOMINAL
VOLTAGE
VOLTAGE
POWER
SUPPLY
UNIT
SIZE
38AUQ
FACTORY-
INSTALLED
OPTION
COMPRESSOR
FAN MOTORS
‡
RANGE
V-Ph-Hz
MIN
MAX
RLA
LRA
FLA (ea)
QTY
MCA
MOCP
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
NONE OR DISCONNECT
CONVENIENCE OUTLET
26.8
31.6
13.9
16.1
10.5
12.2
34.3
39.1
17.1
19.3
12.5
14.2
40.6
45.4
22.5
24.7
16.5
18.2
45
208/230-3-60
187
414
518
187
414
518
187
414
518
253
506
633
253
506
633
253
506
633
19.0
123
1.5
2
2
2
2
2
2
2
2
2
50
20
25
15
15
50
60
25
30
20
20
60
60
30
30
25
30
460-3-60
575-3-60
9.7
7.4
62
50
0.9
0.6
1.5
0.9
0.6
1.5
0.8
0.6
*07
208/230-3-60
460-3-60
25.0
12.2
9.0
164
100
78
*08
575-3-60
208/230-3-60
460-3-60
30.1
16.7
12.2
225
114
80
*12
575-3-60
LEGEND
5. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is
greater than 2%. Use the following formula to determine the percentage
of voltage imbalance.
FLA
LRA
MCA
—
—
—
Full Load Amps
Locked Rotor Amps
Minimum Circuit Amps
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
MOCP —
Maximum Overcurrent
Protection
average voltage
Example: Supply voltage is 208/230-3-60
NEC
RLA
—
—
National Electrical Code
Rated Load Amps
AB = 224 v
BC = 231 v
AC = 226 v
‡
Units are suitable for use on electrical systems where voltage supplied to
the unit terminals is not below or above the listed limits.
NOTES:
(224 + 231 + 226)
3
681
3
1. The MCA and MOCP values are calculated in accordance with the NEC,
Article 440.
Average Voltage =
=
=
2. Motor RLA and LRA values are established in accordance with Underwriters’
Laboratories (UL), Standard 1995.
227
3. The 575-v units are UL, Canada-listed only.
4. Convenience outlet is available as a factory-installed option and is 115-v,
1 ph, 60 Hz.
Determine maximum deviation from average voltage.
(AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v
(AC) 227 – 226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
4
% Voltage Imbalance
= 100 x
= 1.76%
227
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
14
PRE-START-UP
START-UP
IMPORTANT: Before beginning Pre-Start-Up or Start-Up,
review Start-Up Checklist at the back of this book. The
Checklist assures proper start-up of a unit and provides a
record of unit condition, application requirements, system
information, and operation at initial start-up.
38AUQ Units
The compressor crankcase heater must be on for 24 hours
before start-up. After the heater has been on for 24 hours, the
unit can be started. If no time elapsed since the preliminary
charge step was completed, it is unnecessary to wait the 24-
hour period.
Preliminary Checks
1. Check that electric power supply agrees with unit
nameplate data.
2. Verify that the compressor crankcase heater is securely in
place.
3. Check that the compressor crankcase heater has been on
at least 24 hours.
UNIT DAMAGE HAZARD
Do not attempt to start the heat pump system, even
momentarily, until the following steps have been
completed. Compressor damage may result.
4. Recheck for leaks using the procedure outlined in the
Pre-Start-Up section, Leak Test and Dehydration. If any
leaks are detected, repair as required. Evacuate and
dehydrate as described in the Leak Test and Dehydration
section.
5. Ensure that the preliminary charge has been added as
described in the Pre-Start-Up section, Preliminary
Charge.
System Check
1. Check all indoor section and other equipment auxiliary
components. Consult the manufacturer’s instructions
regarding any other equipment connected to the con-
densing unit. If the unit has field-installed accessories,
be sure all are properly installed and correctly wired. If
used, the airflow switch must be properly installed.
2. Be sure the unit is properly leak checked and dehydrated.
3. Check tightness of all electrical connections.
4. Open the liquid line and suction line service valves.
5. Be sure the unit is properly charged. See “Preliminary
Charge”, below.
6. The electrical power source must agree with the unit’s
nameplate rating.
6. All internal wiring connections must be tight, and all
barriers and covers must be in place.
NOTE: The units are factory charged with the required
amount of oil. If recharging in required, use Emkarate
RL 32-3MAF.
Compressor Rotation
On 3-phase units with scroll compressors, it is important to be
certain that the compressor is rotating in the proper direction.
38AUQ units are equipped with a Comfort Alert Diagnostic
Module (CADM). Alert Code 7 indicates reverse power phas-
ing.
7. The crankcase heater must be firmly attached to the com-
pressor crankcase. Be sure the crankcase is warm (heater
must be on for 24 hours before starting compressor).
Turn On Crankcase Heater
To correct phase order:
1. Turn off power to the unit, tag disconnect.
2. Reverse any two of the unit power leads.
3. Reapply power to the compressor, verify correct pres-
sures.
Turn on the crankcase heater for 24 hours before starting the
unit to be sure all the refrigerant is out of the oil. To energize
the crankcase heater, proceed as follows:
1. Set the space thermostat set point above the space tem-
perature so there is no demand for cooling.
2. Close the field disconnect.
To verify the compressor is rotating in the proper direction:
1. Connect service gages to the suction and liquid pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the liquid pressure
should rise, as is normal on any start-up.
Preliminary Charge
Before starting the unit, charge liquid refrigerant into the high
side of the system through the liquid service valve. The amount
of refrigerant added must be at least 80% of the operating
charge listed in the Physical Data table (Tables 1A and 1B on
pages 4 and 5). Allow high and low side pressures to equalize
before starting compressor. If pressures do not equalize readily,
charge vapor on low side of system to assure charge in the
evaporator. Refer to GTAC II, Module 5, Charging, Recover,
Recycling, and Reclamation for liquid charging procedures.
Compressor Overload
This overload interrupts power to the compressor when either
the current or internal motor winding temperature becomes ex-
cessive, and automatically resets when the internal temperature
drops to a safe level. This overload may require up to 60 min-
utes (or longer) to reset. If the internal overload is suspected of
being open, disconnect the electrical power to the unit and
check the circuit through the overload with an ohmmeter or
continuity tester.
UNIT DAMAGE HAZARD
Prior to starting compressor, a preliminary charge of
refrigerant must be added to avoid possible compressor
damage.
15
Reset the space thermostat below ambient so that a call for
cooling is ensured.
Advanced Scroll Temperature Protection (ASTP)
A label located above the terminal box identifies Copeland
Scroll compressor models that contain this technology. See Fig.
14. Advanced Scroll Temperature Protection (ASTP) is a form
of internal discharge temperature protection, that unloads the
scroll compressor when the internal temperature reaches ap-
proximately 300°F. At this temperature, an internal bi-metal
disk valve opens and causes the scroll elements to separate,
which stops compression. Suction and discharge pressures bal-
ance while the motor continues to run. The longer the compres-
sor runs unloaded, the longer it must cool before the bi-metal
disk resets. See Fig. 15.
Never charge liquid into the low-pressure side of system.
Do not overcharge. During charging or removal of refriger-
ant, be sure indoor-fan system is operating. Ensure both
outdoor fan motors are running; bypass any Motormaster
function.
Adjust Refrigerant Charge
The unit must be charged in Cooling mode only. Refer to Cool-
ing Charging Charts, Fig. 16 through Fig. 18. For applications
with line lengths greater than 100 ft, contact Carrier representa-
tive. Vary refrigerant until the conditions of the chart are met.
The charts are based on charging the units to the correct sub-
cooling for the various operating conditions. Accurate pressure
gage and temperature sensing device are required. Connect the
pressure gage to the service port on the liquid line service
valve. Mount the temperature sensing device on the liquid line
close to the liquid line service valve, and insulate it so that out-
door ambient temperature does not affect the reading. Indoor
airflow must be within the unit’s normal operating range. Oper-
ate the unit for a minimum of 15 minutes. Ensure that pressure
and temperature readings have stabilized. Plot the liquid pres-
sure and temperature on chart and add or reduce the charge to
meet the curve. Adjust the charge to conform with the charging
chart, using the liquid pressure and temperature to read the
chart.
Fig. 14 — Advanced Scroll Temperature
Protection Label
Final Checks
Ensure that all safety controls are operating, control panel
covers are on, and the service panels are in place.
120
110
100
90
80
70
60
50
40
30
20
10
0
0
10
20
30
40
50
60
70
80
90
Compressor Unloaded Run Time (Minutes)
*Times are approximate.
NOTE: Various factors, including high humidity, high ambient
temperature, and the presence of a sound blanket will
increase cool-down times.
*Times are approximate.
NOTE: Various factors, including high humidity, high ambient
temperature, and the presence of a sound blanket will
increase cool-down times.
Fig. 15 — Recommended Minimum Cool-Down Time
After Compressor is Stopped
To manually reset ASTP, the compressor should be stopped
and allowed to cool. If the compressor is not stopped, the motor
will run until the motor protector trips, which occurs up to
90 minutes later. Advanced Scroll Temperature Protection will
reset automatically before the motor protector resets, which
may take up to 2 hours.
Start Unit
Set the space thermostat to a set point above space temperature
so that there is no demand for cooling. Close the 38 AUQ dis-
connect switch. Only the crankcase heater will be energized.
16
Fig. 16 — 38AUQ*07 Charging Chart
Fig. 17 — 38AUQ*08 Charging Chart
Fig. 18 — 38AUQ*12 Charging Chart
17
Fig. 19 — 38AUQ Wiring Diagram (208/230-3-60 shown)
18
Solenoid Valve Relay SVR and compressor contactor C.SVR
contacts close, energizing the external liquid line solenoid
valve. Solenoid valve LLSV opens. Compressor contactor C
closes, energizing the compressor motor. Compressor starts
and system runs in Heating mode, providing Stage 1 Heat.
When the space heating load is satisfied terminal W1 is
de-energized. Compressor and outdoor fan operations stop.
Liquid line solenoid LLSV is de-energized and valve closes.
CADM begins its three-minute anti-recycle time delay.
If either the Loss of Charge (LOC) Switch or High Pressure
Switch (HPS) opens while, the compressor contactor C and re-
lay SVR are de-energized; compressor stops and liquid line so-
lenoid is de-energized (valve closes). CADM initiates a TRIP
event (compressor demand sensed at CADM terminal Y but no
current is measured at T1, T2, T3 motor sensors); CADM relay
opens and RED LED is illuminated. TRIP condition maintains
lockout of compressor operation until CADM is manually re-
set. Reset CADM by cycling unit main power.
OPERATING SEQUENCE
Base Unit Controls —
Indoor (Supply) Fan
The indoor fan contactor (IFC) is remotely located at the fan
coil or fan section. If the thermostat fan operation is selected as
Continuous, the IFC is energized and the indoor (supply) fan
motor runs continuously. If the thermostat fan operation is
selected as Automatic, the IFC will be energized on a call for
Cooling or Heating; indoor (supply) fan motor runs. When
thermostat is satisfied, the IFC is de-energized and indoor
(supply) fan motor stops.
Cooling, Unit Without Economizer
When thermostat calls for Cooling, terminal Y1 is energized.
The 38AUQ’s Defrost Board (DFB) receives this input at P2-5.
DFB issues 24-v outputs at OF, P3-7 (RVS1) and P3-10
(COMP1). The OF output energizes outdoor fan relay (OFR);
both outdoor fan motors start and run. The output RVS1 ener-
gizes the reversing valve solenoid (RVS); Reversing valve
switches to Cooling position.
Reversing valve solenoid remains de-energized until the next
Cooling cycle is initiated.
Defrost Cycle
Output PL3-10 (COMP1, 24-v) is received at CADM terminal
Y. If anti-recycle time delay period has not expired, safety pres-
sure switches are open, and/or lockout alarms are active,
CADM relay will remain open, preventing compressor start.
When safety pressure switches are closed and CADM time de-
lay expires, the CADM relay closes, energizing Solenoid Valve
Relay SVR and compressor contactor C. SVR contacts close,
energizing the external liquid line solenoid valve. Solenoid
valve LLSV opens. Compressor contactor C closes, energizing
the compressor motor. Compressor starts and system runs in
Cooling mode.
When space cooling load is satisfied, terminal Y1 is de-enger-
ized. Compressor and outdoor fan motors stop. Liquid line so-
lenoid valve LLSV is de-energized and valve closes. CADM
begins its three-minute anti-recycle time delay.
If either the Loss of Charge (LOC) Switch or High Pressure
Switch (HPS) opens while Y1 remains energized, the compres-
sor contactor C and relay SVR are de-energized; compressor
stops and liquid line solenoid is de-energized (valve closes).
CADM initiates a TRIP event (cooling demand sensed at
CADM terminal Y but no current is measured at T1, T2, T3
motor sensors); CADM relay opens and RED LED is illumi-
nated. TRIP condition maintains lockout of compressor opera-
tion until CADM is manually reset. Reset CADM by cycling
unit main power.
During the Heating Mode, frost and ice can develop on the out-
door coil. Defrost sequence will clear the frost and ice from the
coil by briefly reversing the Heating sequence periodically.
A window to test for a need to run the Defrost cycle opens at a
fixed period after the end of the last Defrost cycle or the previ-
ous test window closed. The window period is determined by
the configuration settings on the DFB’s DIP switches (see unit
wiring diagram).
If the outdoor coil’s Defrost Thermostat switch (DFT) is closed
(shorting DFB terminals DFT1 and DFT1), the Defrost cycle
will start. Output at OF is removed; outdoor fans stop during
the Defrost cycle. Output P3–7 (RVS1) is energized; reversing
valve solenoid RVS is energized and reversing valve changes
position, placing the circuit in a Cooling mode flow, directing
hot gas into the outdoor coil where its heat melts the frost and
loosens the ice on the coil face.
During the Defrost cycle, output EHEAT is also energized (if
not already energized by a thermostat W2 demand); supple-
mental heater will be energized. During the Defrost Cycle,
LED1 on the DFB will be illuminated. The Defrost cycle ends
when DFT opens (as liquid temperature exiting the coil rises
above DFT setpoint) or the defrost cycle runs for 10 minutes.
Output at EHEAT is removed; supplemental heater will be
de-energized (unless thermostat has a W2 demand). Output at
OF is restored; outdoor fans start again. Output P3–7 (RVS1) is
removed; reversing valve returns to Heating position.
Reversing valve solenoid (RVS) is energized in Cooling
modes. This solenoid will remain energized until the next Heat-
ing mode is initiated.
Defrost cycle is fixed at a maximum 10 minute duration limit.
The period to test and initiate a Defrost cycle can be configured
for 30, 60, 90 or 120 minutes.
Cooling, Unit With Economizer
Refer to fan coil unit installation instructions and economizer
accessory installation instructions for operating sequences
when system is equipped with accessory economizer.
Supplemental Heat/Emergency Heat
Supplemental heat type is determined by 40RUQ indoor unit
options and accessories. This heat is initiated when the indoor
unit W2 terminal is energized by the thermostat. (Or as detailed
in “Defrost Cycle” on page 19.) The thermostat may energizes
W2 as supplemental (2nd stage) heat at larger space heating de-
mand, or when selected as emergency heat mode. When the
space heating demand decreases below the 2nd stage limit, or
emergency heat is turned off, W2 is de-energized, and supple-
mental heat is turned off.
Heating
When the thermostat calls for first stage heating, terminal W1
is energized. The 38AUQ’s Defrost Board (DFB) receives this
input at P2-7. The DFB removes the output at P3-7 (RVS1); the
reversing valve solenoid is de-energized and the reversing
valve moves to Heating position.
DFB issues outputs at OF and P3-10 (COMP1). Outdoor fan
relay OFR is energized; both outdoor fan motors run.
Cooling and Heating Shutdown
Output PL3-10 (COMP1, 24-v) is received at CADM terminal
Y. If anti-recycle time delay period has not expired and/or
safety pressure switches are open, outdoor lockout alarms are
active, CADM relay will remain open, preventing compressor
start. When safety pressure switches are closed and CADM
time delay expires, the CADM relay closes, energizing
Partial or complete cooling or heating functions may shutdown
caused by loss of main power, open pressure switches, diag-
nostic alarms, or open internal compressor protections. See
Service section for further details.
19
ROUTINE SYSTEM MAINTENANCE
SERVICE
These items should be part of a routine maintenance program,
to be checked every month or two, until a specific schedule for
each can be identified for this installation:
Refrigeration System
Quarterly Inspection
(and 30 days after initial start)
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
This system uses Puron® refrigerant which has higher
pressures than R-22 and other refrigerants. No other refrig-
erant may be used in this system. Gage set, hoses, and re-
covery system must be designed to handle Puron®. If you
are unsure consult the equipment manufacturer.
Indoor section
• Coil cleanliness checked.
• Return air filter replacement
• Belt tension checked
• Belt condition checked
• Pulley alignment checked
• Fan shaft bearing locking collar tightness checked
• Condensate drain checked
• Blower motor amperage
Compressor Oil
Outdoor Section
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
The compressor in a Puron system uses a polyolester
(POE) oil. This oil is extremely hygroscopic, meaning it
absorbs water readily. POE oils can absorb 15 times as
much water as other oils designed for HCFC and CFC re-
frigerants. Take all necessary precautions to avoid exposure
of the oil to the atmosphere.
• Fan motor mounting bolts tightness
• Compressor mounting bolts
• Fan blade positioning
• Control box cleanliness and wiring condition
• Wire terminal tightness
• Refrigerant charge level
Economizer or Outside Air Damper
• Inlet filters condition
Servicing Systems on Roofs With Synthetic
Materials — POE (polyolester) compressor lubricants are
known to cause long term damage to some synthetic roofing
materials. Exposure, even if immediately cleaned up, may
cause embrittlement (leading to cracking) to occur in one year
or more. When performing any service which may risk expo-
sure of compressor oil to the roof, take appropriate precautions
to protect roofing. Procedures which risk oil leakage include
but are not limited to compressor replacement, repairing refrig-
erants leaks, replacing refrigerant components such as filter
drier, pressure switch, metering device, coil, accumulator, or
reversing valve.
• Check damper travel (economizer)
• Check gear and dampers for debris and dirt
SYNTHETIC ROOF PRECAUTIONARY PROCEDURE
1. Cover extended roof working area with an impermeable
polyethylene (plastic) drop cloth or tarp. Cover an ap-
proximate 10 x 10 ft (3.3 x 3.3 m) area.
2. Cover area in front of the unit service panel with a terry
cloth shop towel to absorb lubricant spills and prevent
run-offs, and protect drop cloth from tears caused by tools
or components.
3. Place terry cloth shop towel inside unit immediately un-
der component(s) to be serviced and prevent lubricant
run-offs through the louvered openings in the base pan.
4. Perform required service.
5. Remove and dispose of any oil contaminated material per
local codes.
20
To check the indoor coil, disconnect the supply fan signal
(A04-A06 direct-drive fans) or contactor (IFC) coil, then start
the circuit in a Cooling Mode (jumper R to Y1 or Y2) and ob-
serve the frosting pattern on the face of the indoor coil. A frost
pattern should develop uniformly across the face of the indoor
coil starting at each tube at the Acutrol nipple locations.
To check the outdoor coil, disconnect the outdoor fan motor.
Start the circuit in a Heating Mode (jumper R to W1 or W2)
and observe the frost pattern on the face of the outdoor coil.
Liquid Line Filter Drier
The factory-provided reversible filter drier is specifically de-
signed to operate with Puron®. Replace the filter drier with
factory-authorized components only with a filter drier with
desiccant made from 100% molecular sieve grade XH-11. Fil-
ter drier must be replaced whenever the refrigerant system is
opened.
When removing a filter drier, use a tubing cutter to cut the drier
from the system. Do not unsweat a filter drier from the sys-
tem. Heat from unsweating will release moisture and contami-
nants from drier into system.
Failure to develop frost at an outlet tube can indicate a plugged
or a missing orifice.
Refrigerant System Pressure Access Ports
Field Refrigerant Access Ports
There are two access ports in each circuit - on the suction tube
near the compressor and on the discharge tube near the com-
pressor. These are brass fittings with black plastic caps. The
hose connection fittings are standard 1/4 SAE Male Flare cou-
plings.
The brass fittings are two-piece High Flow valves, with a re-
ceptacle base brazed to the tubing and an integral spring-closed
check valve core screwed into the base. (See Fig. 20.) This
check valve is permanently assembled into this core body and
cannot be serviced separately; replace the entire core body if
necessary. Service tools are available from RCD that allow the
replacement of the check valve core without having to recover
the entire system refrigerant charge. Apply compressor refrig-
erant oil to the check valve core's bottom o-ring. Install the fit-
ting body with 96 +/-10 in-lbs of torque; do not overtighten.
Field service access to refrigerant pressures is through the
access ports located at the service valves (see Figs 24, 26 and
28). These ports are ¼-in SAE Flare couplings with Schrader
check valves and service caps. Use these ports to admit
nitrogen to the field tubing during brazing, to evacuate the
tubing and evaporator coil, to admit initial refrigerant charge
into the low-side of the system and when checking and
adjusting the system refrigerant charge. When service activities
are completed, ensure the service caps are in place and secure;
check for leaks. If the Schrader check valve must be removed
and re-installed, tighten to 2-3 in-lbs (23-34 N-cm).
Outdoor Coil Metering Devices
The metering devices are multiple fixed–bore devices (Acu-
trol™) swaged into the horizontal outlet tubes from the liquid
header, located at the entrance to each evaporator coil circuit
path. These are non–adjustable. Service requires replacing the
entire liquid header assembly.
SEAT
CORE
(Part No. EC39EZ067)
1/2-20 UNF RH
0.596
45°
30°
WASHER
O-RING
DEPRESSOR PERARI720
1/2" HEX
+.01/-.035
.47
5/8” HEX
FROM FACE OF BODY
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
7/16-20 UNF RH
Fig. 20 — CoreMax Access Port Assembly
21
Control Circuit, 24-V
Heat Pump Controls
The control circuit is protected against overcurrent conditions
by a circuit breaker mounted on control transformer TRAN.
Reset is manual.
Compressor Protection
Compressor Overcurrent
The compressor has internal limbered motor protection.
Compressor Overtemperature
Crankcase Heater
The heater prevents refrigerant migration and compressor oil
dilution during shutdown whenever compressor is not operat-
ing. The heater is wired to cycle with the compressor; the heat-
er is off when compressor is running, and on when compressor
is off.
The crankcase heater will operate as long as the power circuit
is energized.
The compressor has an internal protector to protect it against
excessively high discharge gas temperatures.
High Pressure Switch
The system is provided with a high pressure switch mount-
ed on the discharge line. The switch is stem-mounted and
brazed into the discharge tube. Trip setting is 630 ± 10 psig
(4344 ± 69 kPa) when hot. Reset is automatic at 505 ± 20
psig (3482 ± 140 kPa).
IMPORTANT: Never open any switch or disconnect that
energizes the crankcase heater unless unit is being serviced
or is to be shut down for a prolonged period. After a pro-
longed shutdown on a service job, energize the crankcase
heater for 24 hours before starting the compressor.
Loss of Charge Switch
The system is protected against a loss of charge and low
evaporator coil loading condition by a loss of charge switch
located on the liquid line and a freeze protection thermostat on
the indoor coil. The switch is stem-mounted. Loss of Charge
Switch trip setting is 27 psig ± 3 psig (186 ±21 kPa). Reset is
automatic at 44 ±5 psig (303 ± 35 kPa).
Outdoor Fan Motor Protection
The outdoor fan motor is internally protected against overtem-
perature.
Commercial Defrost Control
The Commercial Defrost Control Board (DFB) coordinates
thermostat demands for supply fan control, 1 or 2 stage
cooling, 1 or 2 stage heating, emergency heating and defrost
control with unit operating sequences. See Fig. 22 for board
arrangement.
The DFB is located in the 38AUQ's main control box (see
Fig. 21). All connections are factory-wired. Refer to Table 12
for details of DFB Inputs and Outputs.
Table 12 —38AUQ Defrost Board I/O and Jumper Configurations
Inputs
Point Name
Type of I/O
DI, 24-vac
DI, 24-vac
DI, 24-vac
24-vac
Connection Pin Number
Unit Connection
Note
G Fan
P2-3
P2-5
Not used
Y1 Cool 1
TB-Y1
TB-W1
TRAN2
TRAN2
DFB
Wi Heat 1
P2-7
R Power
P3-1
C Common
DFT1 Defrost Switch
24-vac, ground
DI, 24-vac
P3-3
DFT-1 to DFT-1
Outputs
Point Name
OF OD Fan
RVS1
Type of I/O
DO, 24-vac
DO, 24-vac
DO, 24-vac
DO, 24-vac
DO, 24-vac
Connection Pin Number
OF
Unit Connection
OFR
Note
P3-7 to P3-5
P3-6 to P3-4
P3-10
RVS1
Energize in COOL
Energize in COOL
RVS2
RVS2
COMP 1
HEAT 2
CADM1-Y
HC-1 (TB4-1)
E-HEAT
Configuration
Point Name
Type of I/O
24-vac
Connection Pin Number
Unit Connection
Unit Connection
Note
Note
Select Jumper
1 Compressor
P1-1
P1-2
24-vac
Speed-Up Configuration
Point Name
Type of I/O
Connection Pin Number
Speed-Up Jumper
Speed-Up Jumper
JMP17
JMP18
Jumper for 1-3 secs: Factory Test, defrost runs for 12 seconds or less
Jumper for 5-20 secs: Forced Defrost, defrost runs for 30 secs if DFT2 is open
22
Fig. 21 — Defrost Control Board (DFB) Location
Defrost
The defrost control mode is a time/temperature sequence.
There are two time components: The continuous run period
and the test/defrost cycle period. The temperature component
is provided by the defrost thermostat (DFT1) mounted on the
outdoor coil.
The continuous run period is a fixed time period between the
end of the last defrost cycle (or start of the current Heating cy-
cle) during which no defrost will be permitted. This period can
be set at 30, 60, 90 or 120 minutes by changing the positions of
DIP switches SW1 and SW2 (see Fig. 23 and Table 13). The
default run period is 60 minutes.
DIP
Switches
Speed-Up
Jumpers
Fig. 22 — Defrost Control Board (DFB) Arrangement
Fig. 23 — DIP Switch Settings — Defrost Board
Reversing valve control
At the end of the continuous run period, the defrost control will
test for a need to defrost. On unit sizes 04-07 (single compres-
sor designs), DFT1 controls the start and termination of the de-
frost cycle. If DFT1 is still open, the defrost test/run window is
closed and the control repeats the continuous run period. If
DFT1 is closed, the defrost cycle is initiated. The defrost period
will end when DFT1 opens (indicating the outdoor coil has
been cleared of frost and ice) or a 10 minute elapsed period ex-
pires, whichever comes first.
The DFB has two outputs for unit reversing valve control. Op-
eration of the reversing valves is based on internal logic; this
application does not use an “O” or “B” signal to determine re-
versing valve position. Reversing valves are energized during
the Cooling stages and de-energized during Heating cycles.
Once energized at the start of a Cooling stage, the reversing
valve will remain energized until the next Heating cycle de-
mand is received. Once de-energized at the start of a Heating
cycle, the reversing valves will remain de-energized until the
next Cooling stage is initiated.
At the end of the unit defrost cycle, the unit will be returned to
Heating cycle for a full continuous run period.
If the space heating load is satisfied and compressor operation
is terminated, the defrost control will remember where the run
period was interrupted. On restart in Heating, the defrost con-
trol will resume unit operation at the point in the run period
where it was last operating.
Compressor control
The DFB receives inputs indicating Stage 1 Cooling and Stage
1 Heating from the space thermostat or unit control system
(PremierLink); it generates commands to start compressors
with or without reversing valve operation to produce Stage 1
Cooling (one compressor), or Stage 1 Heating (both compres-
sors run).
Table 13 —Dip Switch Position
Switch No.
1
2
1
2
1
2
1
2
3
1
0
■
1
0
■
1
0
1
0
■
■
1
0
On
Off
■
■
■
■
■
30 minutes
60 minutes
90 minutes
120 minutes
Fan Delay
23
Defrost Thermostats
Defrost Speedup Functions
These are temperature switches that monitor the surface tem-
perature of the outdoor coil circuits. These switches are mount-
ed on the liquid tube exiting the outdoor coil heating circuits.
These switches close on temperature drop at 30°F (-1°C) and
reset open on temperature rise at 80°F (27°C).
The DFB permits the servicer to speed-up the defrost cycle.
There are two speed-up sequences: relative speed-up and an
immediate forced defrost. Speed-up sequences are initiated by
shorting jumper wires JMP17 and JMP18 together (see
Fig. 22); use a straight-edge screwdriver.
Shorting the jumpers for a period of 1 to 3 secs reduces the de-
frost timer periods by a factor of 0.1 sec/minute. (For example,
the 90 min run period is reduced to 9 secs.) The DFB will step
the unit through a Heating cycle and a Defrost cycle using
these reduced time periods. This mode ends after the Defrost
cycle.
Shorting the jumpers for a period of 5 to 20 secs bypasses the
remaining continuous run period and places the unit in a
Forced Defrost mode. If the controlling DFT is closed when
this mode is initiated, the unit will complete a normal defrost
period that will terminate when the controlling DFT opens or
the 10 minute defrost cycle limit is reached. If the controlling
DFT is open when this mode is initiated, the Defrost cycle will
run for 30 secs. Both modes end at the end of the Defrost cycle.
Indoor Fan Off Delay
The DFB can provide a 30 sec delay on Indoor Fan Off if the
thermostat's fan selector switch is set on AUTO control. DIP
Switch SW3 on the DFB selects use of the fan off time delay
feature. Setting SW3 in the OPEN position turns the Fan Off
Delay feature on; setting SW3 in the CLOSED position dis-
ables this feature. The delay period begins when Y1 demand or
W1 demand by the space thermostat is removed.
24
Fans
Service
Valves
Fig. 24 — 38AUQ*07 Exterior
Outdoor Coil
Defrost
Thermostat
(DFT)
LOC
HPS
High Flow
Access Ports
Fig. 25 — 38AUQ*07 Interior
25
Fans
Service
Valves
Fig. 26 — 38AUQ*08 Exterior
Outdoor Coil
Defrost
Thermostat
(DFT)
LOC
HPS
High Flow
Access Ports
Fig.27 — 38AUQ*08 Interior
26
Fans
Service
Valves
Fig. 28 — 38AUQ*12 Exterior
Outdoor Coil
Defrost
Thermostat
(DFT)
LOC
HPS
High Flow
Access Ports
Fig. 29 — 38AUQ*12 Interior
27
COMFORT ALERT DIAGNOSTIC
MODULE
POWER
(GRN)
The Comfort Alert Diagnostic Module (CADM) monitors and
®
analyzes data from the Copeland Scroll three-phase compres-
sor and the thermostat demand. The CADM also provides a
3-minute anti-recycle time delay to compressor cycling.
The CADM detects causes for electrical and system related
failures. Flashing LEDs communicate the Alert codes to guide
service technicians in accurately and quickly troubleshooting
the system and determining root cause for the failure.
Inputs to the CADM include 24-vac power, demand signal Y,
compressor contactor coil (common side) and compressor
power leads (from the compressor contactor).
ALERT
(YEL)
TRIP
Input
Control Power
Terminal Voltage
(RED)
R
C
24-V
24-V
Fig. 30 — CADM Housing/LED Locations
Control
Common
The ALERT LED indicates an abnormal condition exists in the
system through a flash code. The ALERT LED will blink a
number of times consecutively, pause and the repeat the
process. The number of blinks, defined in Table 14, correlates
to a particular abnormal condition; troubleshooting tips are
provided for each Alert code. Reset of the ALERT may be
automatic or manual. If the fault condition causing the Alert is
self-corrected, the Alert code will be removed and the CADM
will automatically reset and allow the system to restart
normally. Manual reset for lockouts requires that main power
to the 38AUQ unit be recycled after the cause for the Alert
condition has been detected and corrected.
The TRIP LED indicates either a time-delay period is currently
active (RED LED is blinking) or the module has locked out the
compressor (RED LED is on steady). A lockout condition will
occur for some faults as identified in Table 14. Reset of the
TRIP LED requires that unit main power be recycled after the
loss of power to the compressor condition has been detected
and corrected.
Demand
Y
P
T1
T2
T3
24-V
24-V
Line
Line
Line
Contactor Coil
Compressor T1
Compressor T2
Compressor T3
Control of the compressor contactor coil is through a contact
between terminals P and C.
Communications of status and alert conditions is through three
LEDs located on the top edge of the module housing (see
Fig. 30): POWER (green), ALERT (yellow), and TRIP (red).
The POWER LED indicates the presence of control power to
the CADM.
Simultaneous Blinking of YELLOW and RED LEDs indicates
control power input to the CADM is low. Check control circuit
transformer and wiring.
Troubleshooting the CADM Wiring – Flashing LEDs also
indicate wiring problems to the CADM. See Table 15 for
discussion of additional LED flash codes and troubleshooting
instructions.
28
Table 14 — LED Status Codes
Status LED
Status LED Description
Status LED Troubleshooting Information
Green “POWER” Module has power
Supply voltage is present at module terminals
Red “TRIP”
LED On Solid
Thermostat demand signal Y 1. Compressor protector is open
is present, but the
2. Condensing unit power disconnect is open
3. Compressor circuit breaker or fuse(s) is open
compressor is not running.
4. Broken supply wires or connector is not
making contact
5. Compressor power wires not routed through
Comfort Alert
6. Compressor contactor has failed open
Red “TRIP” LED The anti-short cycle timer (3 minutes), in module is preventing compressor
Flashing restart.
Module locks out compressor when compressor damaging ALERT code appears.
Lockout ALERT codes are noted in the Status LED Description.
During a compressor lock out, 24VAC power must be removed from module to manually reset.
Yellow “ALERT”
LED On Solid
A short circuit or over current 1. Compressor contactor coil shorted
condition exists on PROT
2. Electrical load too high for PROT circuit
terminal.
(maximum 1 Amp)
3. 24 V AC wired directly to PROT terminal
Yellow “ALERT”
Flash Code 2
System Pressure Trip
Discharge pressure out of
limits or compressor
overload (if no high pressure
switch in system)
1. High head pressure
2. Condenser coil poor air circulation (dirty,
blocked, damaged)
3. Condenser fan is not running
LOCKOUT
4. If low pressure switch is open:
Refer to Code 3 for troubleshooting
Yellow “ALERT”
Flash Code 3
Short Cycling
Compressor is running only
briefly LOCKOUT
1. If low pressure switch is open:
a. Low refrigerant charge
b. Evaporator blower is not running
c. Evaporator coil is frozen
d. Faulty metering device
e. Condenser coil is dirty
f. Liquid line restriction (filter drier blocked if
present)
2. If high pressure switch is open, go to Flash
Code 2 information
3. Intermittent thermostat demand signal
4. System or control board defective
Yellow “ALERT”
Flash Code 4
Locked Rotor
LOCKOUT
1. Low line voltage to compressor
2. Excessive liquid refrigerant in compressor
3. Compressor bearings are seized
Yellow “ALERT”
Flash Code 5
Open Circuit
1. Condensing unit power disconnect is open
2. Compressor circuit breaker or fuses are open
3. Compressor contactor has failed open
4. High pressure switch is open and requires
manual reset
5. Broken supply wires or connector is not
making contact
6. Unusually long compressor protector reset
time due to extreme ambient temperature
7. Compressor windings are damaged
1. Compressor fuse is open on one phase
2. Broken wire or connector on one phase
3. Compressor motor winding is damaged
4. Utility supply has dropped one phase
Yellow “ALERT”
Flash Code 6
Missing Phase
LOCKOUT
Yellow “ALERT”
Flash Code 7
Reverse Phase
LOCKOUT
1. Compressor running backward due to supply
phase reversal
Yellow “ALERT”
Flash Code 8
Welded Contactor
Compressor always runs
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to
module
Yellow “ALERT”
Flash Code 9
Low Voltage
Control circuit < 18VAC
1. Control circuit transformer is overloaded
2. Low line voltage to compressor
29
Table 15 — CADM Troubleshooting
Miswired Module Indication
Recommended Troubleshooting Action
Green LED is not on,
module does not power up
Determine if both R and C module terminals are
connected. Verify voltage in present at module’s R and C
terminals.
NOTE: The CADM requires a constant nominal 24VAC
power supply. The wiring to the module’s R and C
terminals must be directly from the control transformer.
The module cannot receive its power from another device
that will interrupt the 24VAC power supply. See Fig. 19,
the 38AUQ Wiring Diagram.
Green LED Intermittent,
module powers up only
when compressor runs
Determine if R and Y terminals are wired in reverse. Verify
module’s R and C terminals have a constant source. See
“NOTE” above for details on R and C wiring.
TRIP LED is on but system
and compressor check OK
Verify Y terminal is wired properly per the 38AUQ wiring
diagram (see Fig. 19). Verify voltage at contactor coil falls
below 0.5VAC when off. Verify 24VAQC is present across
Y and C when thermostat demand signal is present. If not,
R and C are reverse wired.
TRIP LED and ALERT LED
flashing together
Verify R and C terminals are supplied with 19-28VAC.
ALERT Flash Code 3
(Compressor Short Cycling)
displayed incorrectly
Verify Y terminal is connected to 24VAC at contactor coil.
Verify voltage at contactor coil falls below 0.5VAC when
off.
ALERT Flash Code 5 or 6
(Open Circuit, Missing Phase)
displayed incorrectly
Check that compressor T1 and T3 wires are through
module’s current sensing holes. Verify Y terminal is
connected to 24VAC at contactor coil. Verify voltage at
contactor coil falls below 0.5VAC when off.
Alert Flash Code *
(Welded Contactor)
displayed incorrectly
Determine if module’s Y terminal is connected. Verify Y
terminal is connected to 24VAC at contactor coil. Verify
24VAC is present across Y and C when thermostat
demand signal is present. If not, R and C are reverse
wired. Verify voltage at contactor coil falls below 0.5VAC
when off.
Lubrication
FAN MOTORS have sealed bearings. No provisions are made
for lubrication.
COMPRESSOR has its own oil supply. Loss of oil due to a
leak in the system should be the only reason for adding oil after
the system has been in operation.
PERSONAL INJURY AND UNIT DAMAGE
HAZARD
Failure to follow this caution may result in personal injury
or equipment damage.
Only approved cleaning is recommended.
Outdoor Coil Maintenance and Cleaning
Recommendation
Routine Cleaning of Indoor Coil Surfaces
Periodic cleaning with Totaline environmentally sound coil
Routine cleaning of coil surfaces is essential to maintain proper
operation of the unit. Elimination of contamination and remov-
al of harmful residues will greatly increase the life of the coil
and extend the life of the unit. The following maintenance and
cleaning procedures are recommended as part of the routine
maintenance activities to extend the life of the coil.
®
cleaner is essential to extend the life of coils. This cleaner is
available from Carrier Replacement Components Division as
part number P902-0301 for one gallon container, and part num-
ber P902-0305 for a 5 gallon container. It is recommended that
all coils, including standard aluminum, pre-coated, copper/cop-
per or E-coated coils be cleaned with the Totaline environmen-
tally sound coil cleaner as described below. Coil cleaning
should be part of the unit's regularly scheduled maintenance
procedures to ensure long life of the coil. Failure to clean the
coils may result in reduced durability in the environment.
Remove Surface Loaded Fibers
Surface loaded fibers or dirt should be removed with a vacuum
cleaner. If a vacuum cleaner is not available, a soft non-metallic
bristle brush may be used. In either case, the tool should be
applied in the direction of the fins. Coil surfaces can be easily
damaged (fin edges can be easily bent over and damage the
coating of a protected coil) if the tool is applied across the fins.
Avoid the use of
• coil brighteners
NOTE: Use of a water stream, such as a garden hose,
against a surface loaded coil will drive the fibers and dirt
into the coil. This will make cleaning efforts more difficult.
Surface loaded fibers must be completely removed prior to
using low velocity clean water rinse.
• acid cleaning prior to painting
• high pressure washers
• poor quality water for cleaning
Totaline environmentally sound coil cleaner is nonflammable,
hypoallergenic, non bacterial, and a USDA accepted biode-
gradable agent that will not harm the coil or surrounding com-
ponents such as electrical wiring, painted metal surfaces, or in-
sulation. Use of non-recommended coil cleaners is strongly
discouraged since coil and unit durability could be affected.
Periodic Clean Water Rinse
A periodic clean water rinse is very beneficial for coils that are
applied in coastal or industrial environments. However, it is
very important that the water rinse is made with very low ve-
locity water stream to avoid damaging the fin edges. Monthly
cleaning as described below is recommended.
30
Clean coil as follows:
1. Turn off unit power, tag disconnect.
2. Remove top panel screws on outdoor coil end of unit.
3. Remove coil corner post. To hold top panel open, place
coil corner post between top panel and center post.
4. Remove screws securing coil to compressor plate and
compressor access panel.
5. Use a water hose or other suitable equipment to flush
down the coil to remove dirt and debris. Clean the outer
surfaces with a stiff brush in the normal manner.
6. Remove the coil corner post from between the top panel
and center post. Reinstall the coil corner post and replace
all screws.
Totaline Environmentally Sound Coil Cleaner
Application Instructions
1. Proper eye protection such as safety glasses is recom-
mended during mixing and application.
2. Remove all surface loaded fibers and dirt with a vacuum
cleaner as described above.
3. Thoroughly wet finned surfaces with clean water and a
low velocity garden hose, being careful not to bend fins.
1
4. Mix Totaline environmentally sound coil cleaner in a 2 /
2
gallon garden spryer according to the instructions includ-
ed with the cleaner. The optimum solution temperature is
100°F (38°C).
NOTE: Do NOT USE water in excess of 130°F (54°C), as
the enzymatic activity will be destroyed.
Totaline Environmentally Sound Coil Cleaner
5. Thoroughly apply Totaline environmentally sound coil
cleaner solution to all coil surfaces including finned area,
tube sheets and coil headers.
6. Hold garden sprayer nozzle close to finned areas and ap-
ply cleaner with a vertical, up-and-down motion. Avoid
spraying in horizontal pattern to minimize potential for
fin damage.
7. Ensure cleaner thoroughly penetrates deep into finned ar-
eas.
8. Interior and exterior finned areas must be thoroughly
cleaned.
9. Finned surfaces should remain wet with cleaning solution
for 10 minutes.
10. Ensure surfaces are not allowed to dry before rinsing. Re-
apply cleaner as needed to ensure 10-minute saturation is
achieved.
Application Equipment
1
• 2- / gallon garden sprayer
2
• Water rinse with low velocity spray nozzle
UNIT DAMAGE HAZARD
Failure to follow this caution may result in corrosion and
damage to the unit.
Harsh chemicals, household bleach or acid or basic clean-
ers should not be used to clean outdoor or indoor coils of
any kind. These cleaners can be very difficult to rinse out of
the coil and can accelerate corrosion at the fin/tube inter-
face where dissimilar materials are in contact. If there is dirt
below the surface of the coil, use the Totaline environmen-
tally sound coil cleaner as described above.
11. Thoroughly rinse all surfaces with low velocity clean wa-
ter using downward rinsing motion of water spray nozzle.
Protect fins from damage from the spray nozzle.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
performance.
High velocity water from a pressure washer, garden hose,
or compressed air should never be used to clean a coil. The
force of the water or air jet will bend the fin edges and in-
crease airside pressure drop.
Service Parts
Listings of service parts for all units are available from the Re-
placement Components Division’s Electronic Parts Informa-
tion Catalog (EPIC). EPIC is available at Totaline stores, dis-
tributor and service office parts departments and on-line at
HVACPartners.com.
When entering EPIC, the full unit model number is required.
The model number includes the Design Revision reference val-
ue (see Fig. 2, Position 13). The unit model number is available
from the unit’s information data plate. (Do not use the “catalog
number” when using EPIC. The “catalog number” suppresses
the Design Revision value; failure to include Design Revision
value may cause an incorrect unit parts list to be displayed.)
When using EPIC, enter first four digits of the model number
only. Find appropriate model from sales packages listed. Be
sure to choose correct voltage and Design Revision.
EPIC is a product of RCD. To comment of the EPIC program,
use the “Comment” button inside the EPIC program.
FASTENER TORQUE VALUES
Table 16 — Torque Values
Compressor mounting bolts
65–75 in–lbs
20 ±2 in–lbs
84 ±2 in–lbs
96 ±10 in–lbs
2–3 in–lbs
(734–847 N–cm)
(226 ±23 N–cm)
(949 ±136 N–cm)
(1085 ±23 N–cm)
(23–34 N–cm)
Condenser fan motor mounting bolts
Condenser fan hub setscrew
High-flow service port
Schrader-type service check valve
31
TROUBLESHOOTING
PROBLEM
CAUSE
REMEDY
Compressor and
Outdoor Fan
Will Not Start.
Power failure.
Call power company.
Fuse blown or circuit breaker tripped.
Replace fuse or reset circuit breaker. Determine root cause.
Replace component.
Defective thermostat, contactor, transformer,
control relay, or capacitor.
Insufficient line voltage.
Determine cause and correct.
Incorrect or faulty wiring.
Check wiring diagram and rewire correctly.
Lower thermostat setting below room temperature.
See problem ``Excessive head pressure.''
Check system for leaks. Repair as necessary.
See problem ``Suction pressure too low.''
Thermostat setting too high.
High pressure switch tripped.
Low pressure switch tripped.
Freeze-up protection thermostat tripped.
Compressor Will Not
Start But Outdoor
Fan Runs.
Faulty wiring or loose connections in compressor Check wiring and repair or replace.
circuit.
Compressor motor burned out, seized, or
internal overload open.
Determine cause. Replace compressor or allow enough time for
internal overload to cool and reset.
Defective run/start capacitor, overload, start
relay.
Determine cause and replace compressor.
One leg of 3-phase power dead.
Refrigerant overcharge or undercharge.
Defective compressor.
Replace fuse or reset circuit breaker. Determine cause.
Recover refrigerant, evacuate system, and recharge to nameplate.
Replace and determine cause.
Compressor Cycles
(Other Than
Normally Satisfying
Thermostat).
Insufficient line voltage.
Determine cause and correct.
Blocked outdoor coil or dirty air filter.
Determine cause and correct.
Defective run/start capacitor, overload, or start
relay.
Determine cause and replace.
Defective thermostat.
Replace thermostat.
Replace.
Faulty outdoor-fan (cooling) or indoor-fan
(heating) motor or capacitor.
Restriction in refrigerant system.
Locate restriction and remove.
Replace filter.
Compressor Operates Dirty air filter.
Continuously.
Unit undersized for load.
Decrease load or increase unit size.
Reset thermostat.
Thermostat set too low (cooling).
Low refrigerant charge.
Locate leak; repair and recharge.
Recover refrigerant, evacuate system, and recharge.
Clean coil or remove restriction.
Air in system.
Outdoor coil dirty or restricted.
Compressor rotating in the wrong direction.
Compressor Makes
Excessive Noise.
Reverse the 3-phase power leads as described in
Start-Up.
Excessive Head
Pressure.
Dirty outside air or return air filter (heating).
Dirty outdoor coil (cooling).
Replace filter.
Clean coil.
Refrigerant overcharged.
Recover excess refrigerant.
Recover refrigerant, evacuate system, and recharge.
Determine cause and correct.
Check for leaks; repair and recharge.
Replace compressor.
Air in system.
Condensing air restricted or air short-cycling.
Low refrigerant charge.
Head Pressure
Too Low.
Compressor scroll plates defective.
Restriction in liquid tube.
Remove restriction.
Excessive Suction
Pressure.
High heat load.
Check for source and eliminate.
Replace compressor.
Compressor scroll plates defective.
Refrigerant overcharged.
Recover excess refrigerant.
Replace filter.
Suction Pressure
Too Low.
Dirty air filter (cooling).
Dirty or heavily iced outdoor coil (heating).
Low refrigerant charge.
Clean outdoor coil. Check defrost cycle operation.
Check for leaks; repair and recharge.
Remove source of restriction.
Increase air quantity. Check filter and replace if necessary.
Reset thermostat.
Metering device or low side restricted.
Insufficient indoor airflow (cooling mode).
Temperature too low in conditioned area.
Field-installed filter drier restricted.
Outdoor ambient below 25°F (cooling).
Outdoor fan motor(s) not operating (heating).
Replace.
Install low?ambient kit.
Check fan motor operation.
32
• Do not install a suction-line filter drier in liquid-line.
• POE oils absorb moisture rapidly. Do not expose oil to
atmosphere.
• POE oils may cause damage to certain plastics and
roofing materials.
APPENDIX A
AIR CONDITIONER AND HEAT PUMP WITH
PURON® — QUICK REFERENCE GUIDE
®
• Puron (R-410A) refrigerant operates at 50 percent to
70 percent higher pressures than R-22. Be sure that
servicing equipment and replacement components are
• Wrap all filter driers and service valves with wet cloth
when brazing.
• A factory approved, liquid-line filter drier is required on
every unit.
®
designed to operate with Puron .
®
• Puron refrigerant cylinders are rose colored.
• Recovery cylinder service pressure rating must be 400
• Do not use an R-22 TXV.
psig, DOT 4BA400 or DOT BW400.
• If indoor unit is equipped with a TXV, it must be
®
®
• Puron
systems should be charged with liquid
changed to a Puron TXV.
refrigerant. Use a commercial type metering device in
the manifold hose when charging into suction line with
compressor operating.
• Never open system to atmosphere while it is under a
vacuum.
• When system must be opened for service, recover
refrigerant, break vacuum with dry nitrogen before
opening system.
• Manifold sets should be 700 psig high side and 180 psig
low side with 550 psig low-side retard.
• Use hoses with 700 psig service pressure rating.
• Always replace filter drier after opening system for
service.
• Leak detectors should be designed to detect HFC
refirgerant.
®
• Do not vent Puron into the atmosphere.
®
• Puron , as with other HFCs, is only compatible with
• Do not use capillary tube coils.
POE oils.
• Observe all warnings, cautions, and bold text.
• Vacuum pumps will not remove moisture from oil.
• Use only factory specified liquid-line filter driers with
rated working pressures greater than 600 psig.
®
• All Puron heat pumps must have indoor TXV.
®
• Do not leave Puron suction line driers in place for
more than 72 hours.
APPENDIX B
WIRING DIAGRAM LIST
38AUQ
Size
*07
Electrical Characteristics
208/230-3-60
460-3-60
Diagram Number
38AU500363
38AU500362
38AU500435
38AU500363
38AU500362
38AU500435
38AU500363
38AU500362
38AU500435
575-3-60
208/230-3-60
460-3-60
575-3-60
208/230-3-60
460-3-60
*08
*12
575-3-60
33
APPENDIX C
MOTORMASTER SENSOR LOCATIONS
MOTOR MASTER SENSOR
MUST BE POSITIONED
ON VAPOR STUB
MOTOR MASTER SENSOR
MUST BE POSITIONED
ON VAPOR STUB
MOTOR MASTER SENSOR
MUST BE POSITIONED
BETWEEN METERING DEVICE
(SECOND FROM TOP)
(FOURTH FROM TOP)
(FOURTH FROM TOP)
AND TUBE SHEET
6T HEAT PUMP
7.5T HEAT PUMP
10T HEAT PUMP
Fig. 31 Motormaster Sensor Locations per Unit Size
Copyright 2009 Carrier Corp • 7310 W. Morris St. • Indianapolis, IN 46231
Printed in U.S.A.
Edition Date: 09/09
Catalog No: 38AUQ-01SI
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Replaces: New
34
III. START UP
START-UP CHECKLIST
I. PRELIMINARY INFORMATION
OUTDOOR: MODEL NO.
SERIAL NO.
SERIAL NO.
INDOOR: AIR HANDLER MANUFACTURER
MODEL NO.
ADDITIONAL ACCESSORIES
II. PRE-START-UP
OUTDOOR UNIT
IS THERE ANY SHIPPING DAMAGE?
IF SO, WHERE:
(Y/N)
WILL THIS DAMAGE PREVENT UNIT START-UP?
(Y/N)
CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT?
(Y/N)
HAS THE GROUND WIRE BEEN CONNECTED?
(Y/N)
HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY?
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY?
(Y/N)
(Y/N)
CONTROLS
ARE THERMOSTAT AND INDOOR FAN CONTROL WIRING CONNECTIONS MADE AND CHECKED?
(Y/N)
ARE ALL WIRING TERMINALS (including main power supply) TIGHT?
HAS CRANKCASE HEATER BEEN ENERGIZED FOR 24 HOURS?
(Y/N)
(Y/N)
INDOOR UNIT
HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE?
ARE PROPER AIR FILTERS IN PLACE? (Y/N)
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT?
(Y/N)
(Y/N)
DO THE FAN BELTS HAVE PROPER TENSION?
(Y/N)
HAS CORRECT FAN ROTATION BEEN CONFIRMED?
(Y/N)
PIPING
ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE INDOOR COILS AS REQUIRED?
(Y/N)
HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR, OUTDOOR AND INDOOR COILS,
TXVs (Thermostatic Expansion Valves), SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS
WITH A LEAK DETECTOR?
(Y/N)
LOCATE, REPAIR, AND REPORT ANY LEAKS.
HAVE LIQUID LINE SERVICE VALVES BEEN OPENED?
HAVE SUCTION SERVICE VALVES BEEN OPENED?
(Y/N)
(Y/N)
CHECK VOLTAGE IMBALANCE
LINE-TO-LINE VOLTS:
(AB + AC + BC)/3 = AVERAGE VOLTAGE =
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE =
AB
V
AC
V
BC
V
V
V
VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =
IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!
CALL LOCAL POWER COMPANY FOR ASSISTANCE.
CL-1
CHECK INDOOR UNIT FAN SPEED AND RECORD.
CHECK OUTDOOR UNIT FAN SPEED AND RECORD.
AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:
SUCTION PRESSURE
SUCTION LINE TEMP
LIQUID PRESSURE
LIQUID LINE TEMP
ENTERING OUTDOOR UNIT AIR TEMP
LEAVING OUTDOOR UNIT AIR TEMP
INDOOR UNIT ENTERING-AIR DB (dry bulb) TEMP
INDOOR UNIT ENTERING-AIR WB (wet bulb) TEMP
INDOOR UNIT LEAVING-AIR DB TEMP
INDOOR UNIT LEAVING-AIR WB TEMP
COMPRESSOR AMPS (L1/L2/L3)
/
/
NOTES:
Copyright 2009 Carrier Corp • 7310 W. Morris St. • Indianapolis, IN 46231
Printed in U.S.A.
Edition Date: 11/09
Catalog No: 38AUQ-01SI
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Pg CL-2
Replaces: New
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