Carrier 38AUQ16-25 Dimensions and installation guide

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53380048-01 Printed in U.S.A. Form 38AUQ-16-25-02SI Pg 1 1-23 Replaces: 38AUQ-16-25-01SI
Installation, Start-Up and Service Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Rated Indoor Airflow (cfm) . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION GUIDELINE . . . . . . . . . . . . . . . . . . . . 2
Replacement /Retrofit — R-22 to Puron Refrigerant 2
•ACIDTEST
• INSTALLATION
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Jobsite Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Step 1 — Step 1 — Plan for Unit Location . . . . . . . . 9
Step 2 — Complete Pre-Installation Checks . . . . . . . 9
• CHECK UNIT ELECTRIC CHARACTERISTIC
• UN-CRATE UNIT
• INSPECT SHIPMENT
• CONSIDER SYSTEM REQUIREMENTS
Step 3 — Prepare Unit Mounting Support . . . . . . . . 9
• SLAB MOUNT
Step 4 — Rig and Mount the Unit . . . . . . . . . . . . . . . 9
•RIGGING
Step 5 — Complete Refrigerant Piping 
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
• CHECK VERTICAL SEPARATION
• PROVIDE SAFETY RELIEF
• REFRIGERANT LINE SIZING
• INSTALL FILTER DRIERS AND MOISTURE
INDICATORS
• INSTALL LIQUID LINE SOLENOID VALVES
• CAPACITY CONTROL LIQUID LINE SOLENOID
VALVE
• MAKE PIPING CONNECTIONS
• EVACUATION/DEHYDRATION
• PRELIMINARY CHARGE
Step 6 — Install Accessories . . . . . . . . . . . . . . . . . . 12
Step 7 — Complete Electrical Connections . . . . . . 12
• FIELD POWER SUPPLY
• UNITS WITHOUT FACTORY-INSTALLED
DISCONNECT
• UNITS WITH FACTORY-INSTALLED DISCONNECT
• ALL UNITS
• VOLTAGE AND CURRENT BALANCE
Convenience Outlets . . . . . . . . . . . . . . . . . . . . . . . . 13
Installing Weatherproof Cover . . . . . . . . . . . . . . . . . 14
• ALL UNITS
• FIELD CONTROL WIRING
• THERMOSTAT
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . 17
Preliminary Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 17
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
38AUQ Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
• PRELIMINARY CHECKS
• COMPRESSOR ROTATION
• COMPRESSOR OVERLOAD
• ADVANCED SCROLL TEMPERATURE PROTECTION
(ASTP)
•STARTUNIT
• ADJUST REFRIGERANT CHARGE
•FINALCHECKS
OPERATING SEQUENCE . . . . . . . . . . . . . . . . . . . . .20
Base Unit Controls . . . . . . . . . . . . . . . . . . . . . . . . . . .20
• INDOOR (SUPPLY) FAN
• COOLING, UNIT WITHOUT ECONOMIZER
• COOLING, UNIT WITH ECONOMIZER
• HEATING
• DEFROST CYCLE
• SUPPLEMENTAL HEAT/EMERGENCY HEAT
• COOLING AND HEATING SHUTDOWN
• FAN CYCLING
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Quarterly Inspection 
(and 30 days after initial start) . . . . . . . . . . . . . . .21
• INDOOR SECTION
Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . .21
• AIR CONDITIONING
ROUTINE SYSTEM MAINTENANCE . . . . . . . . . . . . .22
Quarterly Inspection 
(and 30 days after initial start) . . . . . . . . . . . . . . .22
• INDOOR SECTION
• OUTDOOR SECTION
• ECONOMIZER OR OUTSIDE AIR DAMPER
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . .22
•COMPRESSOROIL
• SERVICING SYSTEMS ON ROOFS WITH SYNTHETIC
MATERIALS
• LIQUID LINE FILTER DRIER
• FIELD REFRIGERANT ACCESS PORTS
• OUTDOOR COIL METERING DEVICES
• REFRIGERANT SYSTEM PRESSURE ACCESS PORTS
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . .24
• COMPRESSOR OVERCURRENT
• COMPRESSOR OVERTEMPERATURE PROTECTION
(IP)
• CRANKCASE HEATER
• HIGH PRESSURE SWITCH
• LOSS OF CHARGE SWITCH
• OUTDOOR FAN MOTOR PROTECTION
• CONTROL CIRCUIT, 24-V
Commercial Defrost Control . . . . . . . . . . . . . . . . . . .24
• REVERSING VALVE CONTROL
• COMPRESSOR CONTROL
•DEFROST
38AUQ16-25
Heat Pump Condensing Units
with Puron®(R-410A) Refrigerant

2
• DEFROST THERMOSTATS
• INDOOR FAN OFF DELAY
• DEFROST SPEEDUP FUNCTIONS
Comfort Alert Diagnostic Module . . . . . . . . . . . . . . 28
Outdoor Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
•FANMOTORS
• COMPRESSOR
Outdoor Coil Maintenance and Cleaning
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . 30
• REMOVE SURFACE LOADED FIBERS
• PERIODIC CLEAN WATER RINSE
• ROUTINE CLEANING OF INDOOR COIL SURFACES
FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . . 32
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . 33
APPENDIX A — AIR CONDITIONER AND HEAT PUMP
WITH PURON®— QUICK REFERENCE GUIDE . 34
APPENDIX B — WIRING DIAGRAM LIST . . . . . . . . . 34
APPENDIX C — LOW AMBIENT OPTION — 
FACTORY INSTALLED . . . . . . . . . . . . . . . . . . . . . 42
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . CL-1
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service, mainte-
nance, 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 mod-
ifying 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 extin-
guisher available. Read these instructions thoroughly and follow
all warnings or cautions attached to the unit. Consult local build-
ing 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 safety-
alert symbol . When you see this symbol on the unit and in in-
structions or manuals, be alert to the potential for personal injury.
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.
GENERAL
See Fig. 1-2 for unit dimensions. For physical data, see Tables 2-3.
For model number nomenclature, see Fig. 3. For date of unit man-
ufacture, see Fig. 4.
Rated Indoor Airflow (cfm)
Table 1below lists the rated indoor airflow used for the AHRI ef-
ficiency rating for the units covered in this document.
INSTALLATION GUIDELINE
Replacement /Retrofit — R-22 to Puron
Refrigerant
Split system heat pumps are intended to be installed with
matching indoor sections only. The 38AUQ heat pump outdoor
units are matched only with same-size 40RUQ indoor sections.
Existing R-22 indoor coils cannot be converted to R-410A heat
pump duty. Only the existing refrigerant piping is a candidate
for retrofit use.
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause in personal injury or
death.
Before performing service or maintenance operations on unit,
always turn off main power switch to unit and install lockout
tag. Unit may have more than one power switch.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
R-410A refrigerant systems operate at higher pressures than
standard R-22 systems. Do not use R-22 service equipment or
components on R-410A refrigerant equipment.
WARNING
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could cause personal injury or
death.
Relieve pressure and recover all refrigerant before system
repair or final unit disposal.
Wear safety glasses and gloves when handling refrigerants.
Keep torches and other ignition sources away from
refrigerants and oils.
CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing, safety glasses and gloves
when handling parts and servicing units.
Table 1 — 38AUQ with 40RUQ
MODEL NUMBERS FULL LOAD AIRFLOW (cfm)
38AUQT/U16 - 40RUQ*16 5625
38AUQT/U25 - 40RUQ*25 7500

3
ACID TEST
If the existing system is being replaced because of a compres-
sor electrical failure, assume acid is in system. If system is be-
ing replaced for any other reason, use an approved acid test kit
to determine acid level. If even low levels of acid are detected,
install a 100 percent activated alumina suction line filter drier
in addition to the replacement liquid-line filter drier. Operate
this system in COOLING ONLY. Remove the suction line filter
drier as soon as possible, with a maximum of 72 hours of
operation.
Recommendation: Install a ball valve in the liquid line at the
filter drier location when installing a suction filter in the suc-
tion line.
INSTALLATION
1. Remove the existing evaporator coil or fan coil and install the
replacement coil.
2. Drain oil from low points and traps in suction line tubing
if they were not replaced.
3. Remove the existing outdoor unit. Install the new outdoor
unit according to these installation instructions.
4. Install the factory-supplied liquid-line filter drier at the
indoor coil just upstream of the TXV.
5. If required, install a 100% activated alumina suction line
filter drier at the outdoor unit.
6. Evacuate and charge the system according to the instruc-
tions in this installation manual.
7. Operate the system for 10 hr. Monitor the pressure drop
across the suction line filter drier. If pressure drop exceeds
3 psig (21 kPa), replace suction-line and liquid-line filter
driers. Be sure to purge system with dry nitrogen and
evacuate when replacing filter driers. Continue to monitor
the pressure drop across suction-line filter drier. Repeat
filter changes is necessary. Never leave suction-line filter
drier in system longer than 72 hours (actual time).
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Never install suction-line filter drier in the liquid-line of an
R-410A system.

4
Fig. 1 — 38AUQ*16 Unit Dimensions
13-1/4
[338]
3-3/4
[95]
16-3/8
[418]
4-5/8
[117]
13-1/2
LEFT SIDE VIEW
SEE DETAIL A
1-3/8 [34.5] POWER ENTRY
WITH 50.0/58.0/65.0 MM K.O.
7/8 [22.2] FIELD
ENTRY SERVICE PORT
ELECTRICAL
DISCONNECT
LOCATION
1-3/4 [44.5]
GUAGE ACCESS
[344]
Y
X
45-1/8
[1148]
CG
CORNER "B"
CORNER "A" CORNER "D"
CORNER "C"
TOP VIEW
SUCTION CONNECTIONS
(SEE CHART FOR SIZE)
6-1/8
[155]
11-1/8
[282]
5-7/8
[149]
DETAIL A
(NOTE POSITION OF CKT 1)
CKT 2 HP CKT 1 HP
LIQUID CONNECTIONS
(SEE CHART FOR SIZE)
OPTIONAL
FACTORY
INSTALLED
DISCONNECT
Z
85
[2158]
86-3/8
[2193]
CG
COMPRESSOR
ACCESS PANEL
H
SERVICE VALVE CONNECTIONS
UNIT SUCTION LIQUID
38AUQ16 1-3/8 [34.9] 1/2 [12.7]
QTY
2 EA
CENTER OF GRAVITY
DIRECTION OF AIR FLOW
DIMENSIONS IN [ ] ARE IN MM
CG
NOTES:
1. MINIMUM CLEARANCE (LOCAL CODES OR JURISDICTION MAY
PREVAIL):
A. BOTTOM TO COMBUSTIBLE SURFACES: 0 INCHES.
B. OUTDOOR COIL, FOR PROPER AIR FLOW: 36 INCHES
ONE SIDE, 12 INCHES THE OTHER. THE SIDE GETTING THE
GREATER CLEARANCE IS OPTIONAL.
C. OVERHEAD: 60 INCHES, TO ASSURE PROPER OUTDOOR FAN
OPERATION.
D. BETWEEN UNITS: CONTROL BOX SIDE, 42 INCHES PER NEC.
E. BETWEEN UNIT AND UNGROUNDED SURFACES: CONTROL BOX
SIDE, 36 INCHES PER NEC.
F. BETWEEN UNIT AND BLOCK OR CONCRETE WALLS AND OTHER
GROUNDED SURFACES: CONTROL BOX SIDE, 42 INCHES PER NEC.
2. WITH EXCEPTION OF THE CLEARANCE FOR THE OUTDOOR
COIL AS STATED IN NOTE 1B, A REMOVABLE FENCE
OR BARRICADE REQUIRES NO CLEARANCE.
3. UNITS MAY BE INSTALLED ON COMBUSTIBLE FLOORS MADE
FROM WOOD OR CLASS A, B OR C ROOF COVERING MATERIAL.
UNIT STD. UNIT WT. CORNER A CORNER B CORNER C CORNER D CENTER OF GRAVITY
LBS. KG. LBS. KG. LBS. KG. LBS. KG. LBS. KG. X Y
38AUQ16 768 348 236 107 183 83 153 69 196 89 39 [990.6] 20 [508] 23 [584.2] 50-3/8 [1279.2]
UNIT HEIGHT
ZH

5
Fig. 2 — 38AUQ*25 Unit Dimensions