Carrier 38AUQ User Manual

38AUQ

Heat Pump Condensing Units
60 Hz

®

with Puron

(R-410A) Refrigerant

Sizes 07, 08, and 12

Installation, Start-Up and

Service Instructions

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

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)

SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 - 31

Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . 20

Compressor Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Servicing Systems on Roofs with

Synthetic Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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

. . . 7

. . 20

Comfort Alert Diagnostic Module . . . . . . . . . . . . . . 28

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

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
safety-alert symbol . When you see this symbol on the unit
and in instructions 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 safety­alert 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.

INSTALLATION GUIDELINE

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause 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.

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.

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.

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 38AUQ units.

Replacement /Retrofit – R22 to Puron

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.

Acid test – If the existing system is being replaced because of a
compressor electrical failure, assume acid is in system. If
system is being 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 hr of operation.

Recommendation: Install a ball valve in the liquid line at the
filter drier location when installing a suction filter in the suction
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.

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 a

®

Puron

system.

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 instruc­tions 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 (21kPa), 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 suction­line filter drier in system longer than 72 hr (actual time).

2

Fig. 1 — 38AUQ*07-12 Unit Dimensions

UNIT

Standard

Weight

Corner

A

Corner

B

Corner

C

Corner

D

Center of Gravity Unit Height

lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H

38AUQ*07

444 201 134 61 97 44 90 41 123 56

23

[584]

26

[660]

13

[330]

42-3/8
[1076]

38AUQ*08

483 219 162 74 110 50 85 39 125 57

20

[508]

24

[610]

13

[330]

42-3/8
[1076]

38AUQ*12

575 261 186 84 126 57 106 48 157 71

21

[533]

24

[610]

23

[584]

50-3/8
[1280]

3

Table 1A — Physical Data — 38AUQ*07-12 Units — 60 Hz English

UNIT SIZE 38AUQ *07 *08 *12
NOMINAL CAPACITY (tons)
OPERATING WEIGHTS (lb)

Aluminum-Fin Coils 444 483 575

REFRIGERANT TYPE

Operating Charge, Typical (lb)

‡

†

Shipping Charge (lb) 10.0 12.0 15.0

COMPRESSOR

Qty...Type 1...Scroll 1...Scroll 1...Scroll

OUTDOOR FANS

Qty...Rpm 2...1100 2...1100 2...1100
Motor Hp
Diameter (in) 22 22 22
Nominal Airflow (Cfm Total) 6,000 6,000 6,000
Watts (Total) 610 610 610

OUTDOOR COIL (Qty)

Face Area (sq ft total) 17.5 23.0 28.1
Rows/Fins per inch (FPI) 2/17 2/17 2/17

CONTROLS

Pressurestat Settings (psig)

High Cutout 630 ±10 630 ±10 630 ±10

Cut-in 505 ±20 505 ±20 505 ±20

Low Cutout 27 ±3 27 ±3 27 ±3

Cut-in 44 ±5 44 ±5 44 ±5

PIPING CONNECTIONS (in. ODS)

Qty...Vapor 1...1
Qty...Liquid

67.510

R-410A

18.0 21.0 27.0

1

/

4

1

/

4

1

/

4

1...Round Tube/Plate Fin (RTPF)

1

/

1...

1...11/

8

3

/

8

1...1/

1...13/

8

2

1...1/

8

2

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
NOMINAL CAPACITY (kW)
OPERATING WEIGHT (kg)

Aluminum-Fin Coils 201 219 261

REFRIGERANT TYPE

Operating Charge, Typical (kg)

‡

†

Shipping Charge (kg) 4.5 5.9 6.8

COMPRESSOR

Qty...Type 1...Scroll 1...Scroll 1...Scroll

CONDENSER FANS

Qty...r/s 2...18 2...18 2...18
Motor Hp NEMA
Diameter (mm) 560 560 560
Nominal Airflow (L/s) 2832 2832 2832
Watts (Total) 610 610 610

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 4344 ±70 4344 ±70 4344 ±70

Cut-in 3482 ±138 3482 ±138 3482 ±138

Low Cutout 186 ±21 186 ±21 186 ±21

Cut-in 303 ±35 303 ±35 303 ±35

PIPING CONNECTIONS (in. ODS)

Qty...Vapor 1...1
Qty...Liquid

21.1 26.4 35.1

R-410A

8.2 9.5 12.2

1

/

4

1

/

4

1

/

4

1...Round Tube/Plate Fin (RTPF)

1

/

1...

1...11/

8

3

/

8

1...1/

1...13/

8

2

1...1/

2

8

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

38AUQA12A0C6–0A0A0

Model Type Packaging

38AU= Carrier Condensing Unit

R--- 410A Refrigerant

0=Standard

Type o f Co il

Electrical Options

Q = Heat Pump Scroll Compressor

A=None

C = Non-Fused Disconnect

1=LTL

Service Options

0=None
1=

Not Used

A=PlaceHolder

Base Unit Controls

0 = Electro-Mechanical Controls

Design Revision

Voltage

1 = 575/3/60
5 = 208 / 230/3/60
6 = 460/3/60

2 = Powered Convenience Outlet

Puronr

1 = Un-powered Convenience Outlet

_____________ ____

Nominal Tonnage

07 = 6 Tons
08 = 7.5 Tons
12 = 10 Tons

Refrigerant Options

A = None
B = Low Ambient

A = Initial Rev (Discrete Model Number)

Not Used

A=Not Used

Not Used

0=Not Used

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

Coil Options

A= Al/Cu
B = Precoat Al/Cu
C = E-Coat Al/Cu
E= Cu/Cu

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POSITION NUMBER
TYPICAL

Year of manufacture (”09” = 2009)3−4

Fig. 2 — Model Number Nomenclature

Fig. 3 — Serial Number Nomenclature

6

REAR:
Min 18” (457 mm)
requried for service

Note: Observe requirements for 39” (914 mm) operating clearance
on either Left or Rear coil opening.

RIGHT:
Min 18” (457 mm)
requried for service

LEFT:
Min 18” (457 mm)
requried for service

FRONT:
42” (1067 mm)

.INSTALLATION

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 in­terfere with unit lifting or rigging.

Step 1 — Plan for Unit Location

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.

NOTE: Consider also the effect of adjacent units on airflow
performance and control box safety clearance.

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 (out­door unit above indoor unit), liquid line lift (outdoor unit below
indoor unit) and hot gas bypass line. Relocate sections to mini­mize the length of interconnecting tubing.

DO NOT BURY REFRIGERATION LINES.

Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto the
unit.

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.

INSPECT SHIPMENT — File a claim with shipping com­pany if the shipment is damaged or incomplete.

CONSIDER SYSTEM REQUIREMENTS

• 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) air­flow 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.

NOTE: If vibration isolators are required for a particular
installation, use the data in Fig. 1 to make the proper
selection.

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.

Step 4 — Rig and Mount the Unit

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.

.

RIGGING — These units are designed for overhead rigging.
Refer to the rigging label for preferred rigging method. Spread­er bars are not required if top crating is left on the unit. All pan­els 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.

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.

Step 5 — Complete Refrigerant Piping
Connections

Refrigerant lines must be carefully designed and constructed to
ensure equipment reliability and efficiency. Line length, pres­sure drop, compressor oil return, and vertical separation are
several of the design criteria that must be evaluated. See
Tab le 2.

IMPORTANT: Do not bury refrigerant piping underground.

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)

R-410A Equivalent Length

Ft 0-38 38-75 75-113 113-150

Model
Nominal Capacity

38AUQ*07 Liquid Line

38AUQ*08 Liquid Line

38AUQ*12 Liquid Line

Legend:

Length Equiv Equivalent tubing length, including effects of refrigeration specialties devices
Liquid Line Tubing size, inches OD.
Max Lift

Cooling

Heating
Suction Line Tube size, inches OD
Charge Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger

NOTE:

Length Linear
Length Equiiv

Max Lift

Cool
Heat

Suction Line

0-25
0-38

3

/

8

25
25

7

/

8

25-50
38-75

3

/

8

50
50

7

/

8

50-75
75-113

3

/

8

48
46

1-1/

8

1

75
60

75-100
113-115

3

/

2

/

39
31

1-1/

8

8

Charge (lbs) 17.8 18.8 20.3 22.6 21.4 24.5

1

/

2

1

/

2

1

/

2

1

/

2

Max Lift

Cool
Heat

Suction Line

25
25

7

/

8

50
50

1-1/81-1/

75
60

8

1-1/

8

100
60

1-1/

8

Charge (lbs) 20.9 23.0 24.9 26.8

Max Lift

Cool
Heat

Suction Line

1

25
25

7

/

2

/

8

1-1/81-1/

1

50
50

/

2

1

/

2

75
60

8

1-1/

8

1

/

2

85
60

1-1/81-3/

Charge (lbs) 26.8 28.8 30.7 33.4 37.2

Maximum liquid lift at maximum permitted liquid line pressure drop

• Indoor unit ABOVE outdoor unit

• Indoor unit BELOW outdoor unit

suction line size (where applicable)
For applications with linear length greater than 100 ft (30.5 m), contact your local Carrier representative.

1

/

2

100
60

5

/

8

100
60

8

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.

IMPORTANT: A refrigerant receiver is not provided
with the unit. Do not install a receiver.

Table 3 — Maximum Vertical Separation*

UNIT 38AUQ UNIT 40RUQ

07 07 50 (15.2)
08 08 60 (18.3)
12 12 60 (18.3)

*Vertical distance between indoor and outdoor units.

DISTANCE FT (M)

Unit 38AUQ

Above Unit 40RMQ

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)

Model-Size Qty

38AUQ*07 1
38AUQ*08 1
38AUQ*12 1

Liquid

Line OD

3

/8-in 8 cu. in. KH43LG091

1

/2-in 16 cu. in. KH43LG085

1

/2-in 16 cu. in. KH43LG085

Desiccant

Vol ume

Part

Number Ref

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.

8

Table 5 — Refrigerant Specialties Part Numbers.

LIQUID LINE

SIZE (in.)

3

/

8

1

/

2

5

/

8

†

38AUD units require TWO sets of parts.

LIQUID LINE

SOLENOID VALVE (LLSV)

ALC-066208 AMG-24/50-60 HMI-1TT3

ALC-066209

†

ALC-066212 AMG-24/50-60 HMI-1TT5

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.

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.

CAPACITY CONTROL LIQUID LINE SOLENOID VALVE
Evaporator capacity control via liquid solenoid valve is not rec­ommended for use with 38AUQ models.

8 DIAMS

MIN

LEGEND

EQUALIZER LINE

SIGHT GLASS
A LOCATION

TXV

FILTER DRIER
A LOCATION

FLOW

LIQUID
LINE
SOLENOID
VALVE

INDOOR
COIL CKT

AIRFLOW

TXV
SENSING
BULB

15 DIAMS

MIN

10

DIAMS

TXV — Thermostatic Expansion Valve

Fig.5 — Location of Sight Glass(es) and Filter Driers

(typical 38AUQ/40RUQ size 07 & 08 systems)

LLSV
COIL

SIGHT

GLASS

AMG-24/50-60 HMI-1TT4

INDOOR
COIL CKT 2

AIRFLOW

INDOOR
COIL CKT 1

AIRFLOW

TXV
SENSING
BULB

15 DIAMS

MIN

TXV
SENSING
BULB

15 DIAMS

MIN

10

DIAMS

10

DIAMS

TXV — Thermostatic Expansion Valve

Fig.6 — Location of Sight Glass(es) and Filter Driers

(typical 38AUQ/40RUQ size 12 system)

Table 6 — Minimum Outdoor Air Operating Temperature

UNIT%COMPRESSOR

38AUQ07
38AUQ08 35 (1.7) –20 (–28.9)
38AUQ12 35 (1.7) –20 (–28.9)

*Applies to Cooling mode of operation only.

†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.

CAPACITY

100

Table 7 — Insulation for Vapor Line Exposed

LENGTH OF EXPOSED

VAP OR L INE*

ft m in. mm

10 3
25 8
35 11
50 15

*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 capac­ity should be reduced 1000 Btuh (295 W) if over 35 ft (11 m) of
vapor line with
ditions.

†Closed cell foam insulation with a thermal conductivity of: 0.28 Btu

2

• in./ft

• h • °F (0.04 W/m • °C).

3

/4 in. (19 mm) insulation is exposed to outdoor con-

FILTER

DRIER

Provided with unit

See Table 4

EQUALIZER LINE

TXV

CKT 2

8 DIAMS

MIN

TXV

CKT 1

8 DIAMS

MIN

LEGEND

MINIMUM OUTDOOR

TEMP — F (C)*

Standard Unit

35 (1.7) –20 (–28.9)

to Outdoor Conditions

INSULATION THICKNESS†

3

/

8

1

/

2

3

/

4

3

/

4

SIGHT GLASS
LOCATION

FILTER DRIER
LOCATION

Head Pressure

Control†

10
13
19
19

FLOW

LIQUID
LINE
SOLENOID
VALVE

9

MAKE PIPING CONNECTIONS — Piping connections at

Factory
High-Flow
Access Port

Service Valve
with Stem Cap

Field Service
Access Port
(Schrader core)

Sweat
Connection

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. Con­nect 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.

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-and­bubbles.

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, follow­ing description in GTAC II, Module 4, System Dehydration.

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
Suction 1-

/2 in

1

/8 in.

Charge 23.0 lbs (at 75-ft linear length)

80% of Operating Charge:

0.80 x 23.0 = 17.6 lbs
Factory Shipping Charge: 12 lbs
Field-charge quantity: 17.6 lbs –12.0 lbs = 5.6 lbs
For linear line lengths longer than 100 ft (30.5 m), contact your

local Carrier representative for system charge value.

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.

Step 7 — Complete Electrical Connections

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.

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.

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.

NOTE: Check all factory and field electrical connections
for tightness. Field-supplied wiring shall conform with the
limitations of 63°F (33°C) rise.

Field Power Supply —

If equipped with optional Powered Convenience Outlet: The
power source leads to the convenience outlet's transformer pri­mary 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 volt­age shown on the nameplate. If the 208/230-v unit is to be con­nected 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 trans­former. Refer to unit label diagram for additional information.

10

Field power wires are connected to the unit at line-side pres-

COPPER

WIRE ONLY

ELECTRIC

DISCONNECT

SWITCH

ALUMINUM

WIRE

11 1 3

L1

L2 L3

CTB1

208/230-3-60

460-3-60
575-3-60

Units Without Disconnect Option

Units With Disconnect Option

2

4

6

1

3

5

L1

L2

L3

Optional

Disconnect

Switch

Disconnect factory test leads; discard.

Factory

Wiring

Disconnect

per

NEC

sure lugs on compressor contactor C and TB1 (see wiring dia­gram label for control box component arrangement) or at facto­ry-installed option non-fused disconnect switch. Max wire size
is #4 AWG (copper only).

NOTE: TEST LEADS - Unit may be equipped with short
leads (pigtails) on the field line connection points on con­tactor 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.

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.

(See Fig. 8.)

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.

Units with Factory-Installed Disconnect —

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.

Fig. 9 — Power Wiring Connections

All field wiring must comply with the NEC and local
requirements.

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.

Convenience Outlets

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.

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

UNIT

VOLTAGE

CONNECTASPRIMARY

CONNECTIONS

TRANSFORMER

TERMINALS

208,

230

240

L1: RED + YEL
L2: BLU + GRA

H1 + H3
H2 + H4

460 480

L1: RED
Splice BLU +
YEL
L2: GRA

H1

H2 + H3

H4

575 600

L1: RED
L2: GRA

H1
H2

Outlet

GFCI

Pwd-CO

Fuse

Switch

Control Box

Access Panel

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.

Unit-powered type: A unit-mounted transformer is factory­installed 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 unit­mounted 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.

Pwd-CO

Transformer

UNIT

VOLTAGE

208,

CONNECT

230

460 480

575 600

240

AS

PRIMARY

CONNECTIONS

L1: RED + YEL
L2: BLU + GRA

L1: RED
Splic e BLU +
YEL
L2: GRA

L1: RED
L2: GRA

TRANSFORMER

TERMINALS

H1 + H3
H2 + H4

H2 + H3

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 re­ceptacle 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 unit­mounded 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
approximately

12

1

/2-in (13 mm) under screw heads are exposed.

H1

H4

H1
H2

Press the gasket over the screw heads. Slip the backing plate

RECEPTACLE
NOT INCLUDED

COVER – WHILE-IN-USE
WEATHERPROOF

BASE PLATE FOR
GFCI RECEPTACLE

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

R

Y1

G

O/B/Y2

C

W2

W1

(Notes 1, 2)

(Note 3)

(Note 4)

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.

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 33CS­58SI for details on connecting the PremierLink controller and
its various sensors.

Fig. 12 — Weatherproof Cover Installation

All Units —

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.

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 field­supplied 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.

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).

Fig. 13 — Typical Remote Thermostat Connections

13

Table 8 — Electrical Data — 38AUQ*07-12 60 Hz Units

Example: Supply voltage is 208/230-3-60

AB = 224 v
BC = 231 v
AC = 226 v

Average Voltage =

(224 + 231 + 226)

=

681

3

3

=227

Determine maximum deviation from average voltage.
(AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v
(AC)227–226=1v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.

% Voltage Imbalance = 100 x

4

227

=1.76%

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.

%VoltageImbalance =100x

max voltage deviation from average voltage

average voltage

NOMINAL
VO LTAGE

V-Ph-Hz MIN MAX RLA LRA FLA (ea) QTY MCA MOCP

208/230-3-60 187 253 19.0 123 1.5 2

460-3-60 414 506 9.7 62 0.9 2

575-3-60 518 633 7.4 50 0.6 2

208/230-3-60 187 253 25.0 164 1.5 2

460-3-60 414 506 12.2 100 0.9 2

575-3-60 518 633 9.0 78 0.6 2

208/230-3-60 187 253 30.1 225 1.5 2

460-3-60 414 506 16.7 114 0.8 2

575-3-60 518 633 12.2 80 0.6 2

FLA —
LRA —
MCA —
MOCP —

UNIT

SIZE

38AUQ

NONE OR DISCONNECT
CONVENIENCE OUTLET 31.6 50

*07

NONE OR DISCONNECT
CONVENIENCE OUTLET 16.1 25
NONE OR DISCONNECT
CONVENIENCE OUTLET 12.2 15
NONE OR DISCONNECT
CONVENIENCE OUTLET 39.1 60

*08

NONE OR DISCONNECT
CONVENIENCE OUTLET 19.3 30
NONE OR DISCONNECT
CONVENIENCE OUTLET 14.2 20
NONE OR DISCONNECT
CONVENIENCE OUTLET 45.4 60

*12

NONE OR DISCONNECT
CONVENIENCE OUTLET 24.7 30
NONE OR DISCONNECT
CONVENIENCE OUTLET 18.2 30

LEGEND

Full Load Amps
Locked Rotor Amps
Minimum Circuit Amps
Maximum Overcurrent

FACTORY-

INSTALLED

OPTION

Protection

NEC —
RLA —

‡

Units are suitable for use on electrical systems where voltage supplied to

NOTES:

1. The MCA and MOCP values are calculated in accordance with the NEC,

2. Motor RLA and LRA values are established in accordance with Underwriters’

3. The 575-v units are UL, Canada-listed only.

4. Convenience outlet is available as a factory-installed option and is 115-v,

National Electrical Code
Rated Load Amps

the unit terminals is not below or above the listed limits.

Article 440.

Laboratories (UL), Standard 1995.

1 ph, 60 Hz.

VOLTAGE

RANGE

COMPRESSOR FAN MOTORS

‡

POWER
SUPPLY

26.8 45

13.9 20

10.5 15

34.3 50

17.1 25

12.5 20

40.6 60

22.5 30

16.5 25

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.

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.

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.

System Check

1. Check all indoor section and other equipment auxiliary
components. Consult the manufacturer’s instructions
regarding any other equipment connected to the con­densing 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.

7. The crankcase heater must be firmly attached to the com­pressor crankcase. Be sure the crankcase is warm (heater
must be on for 24 hours before starting compressor).

Turn On Crankcase Heater

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 tem­perature so there is no demand for cooling.

2. Close the field disconnect.

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.

UNIT DAMAGE HAZARD

Prior to starting compressor, a preliminary charge of
refrigerant must be added to avoid possible compressor
damage.

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 24­hour 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.

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.

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 phas­ing.

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 pres­sures.

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.

Compressor Overload

This overload interrupts power to the compressor when either
the current or internal motor winding temperature becomes ex­cessive, and automatically resets when the internal temperature
drops to a safe level. This overload may require up to 60 min­utes (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.

15

Advanced Scroll Temperature Protection (ASTP)

0

10

20

30

40

50

60

70

80

90

100

110

120

0 10 20 30 40 50 60 70 80 90

Compressor Unloaded Run Time (Minutes)

Recommended Cooling 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.

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 ap­proximately 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 bal­ance while the motor continues to run. The longer the compres­sor runs unloaded, the longer it must cool before the bi-metal
disk resets. See Fig. 15.

Fig. 14 — Advanced Scroll Temperature

Protection Label

Reset the space thermostat below ambient so that a call for
cooling is ensured.

Never charge liquid into the low-pressure side of system.
Do not overcharge. During charging or removal of refriger­ant, 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 Cool­ing Charging Charts, Fig. 16 through Fig. 18. For applications
with line lengths greater than 100 ft, contact Carrier representa­tive. Vary refrigerant until the conditions of the chart are met.
The charts are based on charging the units to the correct sub­cooling 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 out­door ambient temperature does not affect the reading. Indoor
airflow must be within the unit’s normal operating range. Oper­ate the unit for a minimum of 15 minutes. Ensure that pressure
and temperature readings have stabilized. Plot the liquid pres­sure 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. 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 dis­connect switch. Only the crankcase heater will be energized.

Final Checks

Ensure that all safety controls are operating, control panel
covers are on, and the service panels are in place.

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

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 ener­gizes the reversing valve solenoid (RVS); Reversing valve
switches to Cooling position.

Output PL3-10 (COMP1, 24-v) is received at CADM terminal
Y. If anti-recycle time delay period has not expired, safety pres­sure 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 de­lay 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-enger­ized. Compressor and outdoor fan motors stop. Liquid line so­lenoid 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 compres­sor 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 illumi­nated. TRIP condition maintains lockout of compressor opera­tion until CADM is manually reset. Reset CADM by cycling
unit main power.

Reversing valve solenoid (RVS) is energized in Cooling
modes. This solenoid will remain energized until the next Heat­ing mode is initiated.

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.

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.

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

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 re­lay SVR are de-energized; compressor stops and liquid line so­lenoid 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 re­set. Reset CADM by cycling unit main power.

Reversing valve solenoid remains de-energized until the next
Cooling cycle is initiated.

Defrost Cycle

During the Heating Mode, frost and ice can develop on the out­door 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 previ­ous 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); supple­mental 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.

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.

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 de­mand, 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 supple­mental heat is turned off.

Cooling and Heating Shutdown

Partial or complete cooling or heating functions may shutdown
caused by loss of main power, open pressure switches, diag­nostic 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:

Quarterly Inspection
(and 30 days after initial start)

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

Outdoor Section

• 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

• Check damper travel (economizer)

• Check gear and dampers for debris and dirt

Refrigeration System

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 refrig­erant may be used in this system. Gage set, hoses, and re­covery system must be designed to handle Puron®. If you
are unsure consult the equipment manufacturer.

Compressor Oil

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 re­frigerants. Take all necessary precautions to avoid exposure
of the oil to the atmosphere.

Servicing Systems on Roofs With Synthetic
Materials —

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 expo­sure 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 refrig­erants leaks, replacing refrigerant components such as filter
drier, pressure switch, metering device, coil, accumulator, or
reversing valve.

SYNTHETIC ROOF PRECAUTIONARY PROCEDURE

1. Cover extended roof working area with an impermeable
polyethylene (plastic) drop cloth or tarp. Cover an ap­proximate 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 un­der 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.

POE (polyolester) compressor lubricants are

20

Liquid Line Filter Drier

1/2-20 UNF RH

30°

0.596

.47

5/8” HEX

SEAT

CORE

WASHER

DEPRESSOR PER ARI 720
+.01/-.035
FROM FACE OF BODY

7/16-20 UNF RH

O-RING

45°

1/2" HEX

This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.

(Part No. EC39EZ067)

The factory-provided reversible filter drier is specifically de­signed 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. Fil­ter 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 sys­tem. Heat from unsweating will release moisture and contami­nants from drier into system.

Field Refrigerant Access Ports

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 (Acu­trol™) 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.

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 ob­serve 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.

Failure to develop frost at an outlet tube can indicate a plugged
or a missing orifice.

Refrigerant System Pressure Access Ports

There are two access ports in each circuit - on the suction tube
near the compressor and on the discharge tube near the com­pressor. These are brass fittings with black plastic caps. The
hose connection fittings are standard 1/4 SAE Male Flare cou­plings.

The brass fittings are two-piece High Flow valves, with a re­ceptacle 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 refrig­erant oil to the check valve core's bottom o-ring. Install the fit­ting body with 96 +/-10 in-lbs of torque; do not overtighten.

Fig. 20 — CoreMax Access Port Assembly

21

Heat Pump Controls

Compressor Protection

Compressor Overcurrent

The compressor has internal limbered motor protection.

Compressor Overtemperature

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 mount­ed 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).

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 overtem­perature.

Control Circuit, 24-V

The control circuit is protected against overcurrent conditions
by a circuit breaker mounted on control transformer TRAN.
Reset is manual.

Crankcase Heater

The heater prevents refrigerant migration and compressor oil
dilution during shutdown whenever compressor is not operat­ing. The heater is wired to cycle with the compressor; the heat­er 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.

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 pro­longed shutdown on a service job, energize the crankcase
heater for 24 hours before starting the compressor.

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 Connection Pin Number Unit Connection Note

G Fan DI, 24-vac P2-3 Not used
Y1 Cool 1 DI, 24-vac P2-5 TB-Y1
Wi Heat 1 DI, 24-vac P2-7 TB-W1
R Power 24-vac P3-1 TRAN2
C Common 24-vac, ground P3-3 TRAN2
DFT1 Defrost Switch DI, 24-vac DFT-1 to DFT-1 DFB

Outputs

Point Name Type of I/O Connection Pin Number Unit Connection Note

OF OD Fan DO, 24-vac OF OFR
RVS1 DO, 24-vac P3-7 to P3-5 RVS1 Energize in COOL
RVS2 DO, 24-vac P3-6 to P3-4 RVS2 Energize in COOL
COMP 1 DO, 24-vac P3-10 CADM1-Y
HEAT 2 DO, 24-vac E-HEAT HC-1 (TB4-1)

Configuration

Point Name Type of I/O Connection Pin Number Unit Connection Note

Select Jumper 24-vac P1-1
1 Compressor 24-vac P1-2

Speed-Up Configuration

Point Name Type of I/O Connection Pin Number Unit Connection Note

Speed-Up Jumper JMP17
Speed-Up Jumper 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

DIP
Switches

Speed-Up
Jumpers

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 cy­cle) 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.

Fig. 22 — Defrost Control Board (DFB) Arrangement

Reversing valve control

The DFB has two outputs for unit reversing valve control. Op­eration of the reversing valves is based on internal logic; this
application does not use an “O” or “B” signal to determine re­versing 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 de­mand 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.

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 compres­sors run).

Table 13 —Dip Switch Position

Switch No.

12 12 12 12 3

■ 1 ■ 11■■1On

1
0

30 minutes 60 minutes 90 minutes 120 minutes Fan Delay

■ 0 ■ 0 ■■00■ Off

Fig. 23 — DIP Switch Settings — Defrost Board

At the end of the continuous run period, the defrost control will
test for a need to defrost. On unit sizes 04-07 (single compres­sor designs), DFT1 controls the start and termination of the de­frost 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 ex­pires, whichever comes first.

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 con­trol will resume unit operation at the point in the run period
where it was last operating.

23

Defrost Thermostats

These are temperature switches that monitor the surface tem­perature of the outdoor coil circuits. These switches are mount­ed 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).

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 dis­ables this feature. The delay period begins when Y1 demand or
W1 demand by the space thermostat is removed.

Defrost Speedup Functions

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 de­frost 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.

24

Fans

Service
Valves

LOC

HPS

High Flow
Access Ports

Outdoor Coil

Defrost
Thermostat
(DFT)

Fig. 24 — 38AUQ*07 Exterior

Fig. 25 — 38AUQ*07 Interior

25

Fans

LOC

HPS

High Flow
Access Ports

Outdoor Coil

Defrost
Thermostat
(DFT)

Service
Valves

Fig. 26 — 38AUQ*08 Exterior

Fig.27 — 38AUQ*08 Interior

26

Fans

Service
Valves

Defrost
Thermostat
(DFT)

Fig. 28 — 38AUQ*12 Exterior

Outdoor Coil

HPS

High Flow
Access Ports

LOC

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 compres­sor 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).

Input Terminal Voltage

Control Power

Control
Common

R 24-V

C 24-V

Demand Y 24-V
Contactor Coil P 24-V
Compressor T1 T1 Line
Compressor T2 T2 Line
Compressor T3 T3 Line

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.

ALERT
(YEL)

TRIP
(RED)

Fig. 30 — CADM Housing/LED Locations

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.

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

Red “TRIP” LED
Flashing

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

Yellow “ALERT”
Flash Code 2

Yellow “ALERT”
Flash Code 3

Yellow “ALERT”
Flash Code 4

Yellow “ALERT”
Flash Code 5

Yellow “ALERT”
Flash Code 6

Yellow “ALERT”
Flash Code 7

Yellow “ALERT”
Flash Code 8

Yellow “ALERT”
Flash Code 9

Thermostat demand signal Y
is present, but the
compressor is not running.

The anti-short cycle timer (3 minutes), in module is preventing compressor
restart.

A short circuit or over current
condition exists on PROT
terminal.

System Pressure Trip
Discharge pressure out of
limits or compressor
overload (if no high pressure
switch in system)
LOCKOUT

Short Cycling
Compressor is running only
briefly LOCKOUT

Locked Rotor
LOCKOUT

Open Circuit 1. Condensing unit power disconnect is open

Missing Phase
LOCKOUT

Reverse Phase
LOCKOUT

Welded Contactor
Compressor always runs

Low Voltage
Control circuit < 18VAC

1. Compressor protector is open

2. Condensing unit power disconnect is open

3. Compressor circuit breaker or fuse(s) is open

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

1. Compressor contactor coil shorted

2. Electrical load too high for PROT circuit
(maximum 1 Amp)

3. 24 V AC wired directly to PROT terminal

1. High head pressure

2. Condenser coil poor air circulation (dirty,
blocked, damaged)

3. Condenser fan is not running

4. If low pressure switch is open:

Refer to Code 3 for troubleshooting

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

1. Low line voltage to compressor

2. Excessive liquid refrigerant in compressor

3. Compressor bearings are seized

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

1. Compressor running backward due to supply
phase reversal

1. Compressor contactor has failed closed

2. Thermostat demand signal not connected to
module

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

Green LED Intermittent,
module powers up only
when compressor runs

TRIP LED is on but system
and compressor check OK

TRIP LED and ALERT LED
flashing together

ALERT Flash Code 3
(Compressor Short Cycling)
displayed incorrectly

ALERT Flash Code 5 or 6
(Open Circuit, Missing Phase)
displayed incorrectly

Alert Flash Code *
(Welded Contactor)
displayed incorrectly

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.

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.

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.

Verify R and C terminals are supplied with 19-28VAC.

Verify Y terminal is connected to 24VAC at contactor coil.
Verify voltage at contactor coil falls below 0.5VAC when
off.

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.

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.

Outdoor Coil Maintenance and Cleaning
Recommendation

Routine cleaning of coil surfaces is essential to maintain proper
operation of the unit. Elimination of contamination and remov­al 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.

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.

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.

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 ve­locity water stream to avoid damaging the fin edges. Monthly
cleaning as described below is recommended.

PERSONAL INJURY AND UNIT DAMAGE
HAZARD

Failure to follow this caution may result in personal injury
or equipment damage.

Only approved cleaning is recommended.

Routine Cleaning of Indoor Coil Surfaces

Periodic cleaning with Totaline® environmentally sound 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 num­ber P902-0305 for a 5 gallon container. It is recommended that
all coils, including standard aluminum, pre-coated, copper/cop­per or E-coated coils be cleaned with the Totaline environmen­tally 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.

Avoid the use of

• coil brighteners

• 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 biode­gradable agent that will not harm the coil or surrounding com­ponents such as electrical wiring, painted metal surfaces, or in­sulation. Use of non-recommended coil cleaners is strongly
discouraged since coil and unit durability could be affected.

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 Equipment

•2-1/2 gallon garden sprayer

• 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 clean­ers 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 inter­face where dissimilar materials are in contact. If there is dirt
below the surface of the coil, use the Totaline environmen­tally sound coil cleaner as described above.

Totaline Environmentally Sound Coil Cleaner
Application Instructions

1. Proper eye protection such as safety glasses is recom­mended 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.

4. Mix Totaline environmentally sound coil cleaner in a 2
gallon garden spryer according to the instructions includ­ed 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.

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 ap­ply 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 ar­eas.

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. Re­apply cleaner as needed to ensure 10-minute saturation is
achieved.

11. Thoroughly rinse all surfaces with low velocity clean wa­ter using downward rinsing motion of water spray nozzle.
Protect fins from damage from the spray nozzle.

1

/

2

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 in­crease airside pressure drop.

FASTENER TORQUE VALUES

Table 16 — Torque Values

Compressor mounting bolts 65–75 in–lbs (734–847 N–cm)
Condenser fan motor mounting bolts 20 ±2 in–lbs (226 ±23 N–cm)
Condenser fan hub setscrew 84 ±2 in–lbs (949 ±136 N–cm)
High-flow service port 96 ±10 in–lbs (1085 ±23 N–cm)
Schrader-type service check valve 2–3 in–lbs (23–34 N–cm)

Service Parts

Listings of service parts for all units are available from the Re­placement Components Division’s Electronic Parts Informa­tion Catalog (EPIC). EPIC is available at Totaline stores, dis­tributor 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 val­ue (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.

31

TROUBLESHOOTING

PROBLEM CAUSE REMEDY

Compressor and
Outdoor Fan
Will Not Start.

Compressor Will Not
Start But Outdoor
Fan Runs.

Compressor Cycles
(Other Than
Normally Satisfying
Thermostat).

Compressor Operates
Continuously.

Compressor Makes
Excessive Noise.

Excessive Head
Pressure.

Head Pressure
Too Low.

Excessive Suction
Pressure.

Suction Pressure
Too Low.

Power failure. Call power company.
Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker. Determine root cause.
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.
Thermostat setting too high. Lower thermostat setting below room temperature.
High pressure switch tripped. See problem ``Excessive head pressure.''
Low pressure switch tripped. Check system for leaks. Repair as necessary.
Freeze-up protection thermostat tripped. See problem ``Suction pressure too low.''
Faulty wiring or loose connections in compressor

circuit.
Compressor motor burned out, seized, or

internal overload open.
Defective run/start capacitor, overload, start

relay.
One leg of 3-phase power dead. Replace fuse or reset circuit breaker. Determine cause.
Refrigerant overcharge or undercharge. Recover refrigerant, evacuate system, and recharge to nameplate.
Defective compressor. Replace and determine cause.
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.
Defective thermostat. Replace thermostat.
Faulty outdoor-fan (cooling) or indoor-fan

(heating) motor or capacitor.
Restriction in refrigerant system. Locate restriction and remove.
Dirty air filter. Replace filter.
Unit undersized for load. Decrease load or increase unit size.
Thermostat set too low (cooling). Reset thermostat.
Low refrigerant charge. Locate leak; repair and recharge.
Air in system. Recover refrigerant, evacuate system, and recharge.
Outdoor coil dirty or restricted. Clean coil or remove restriction.
Compressor rotating in the wrong direction. Reverse the 3-phase power leads as described in

Dirty outside air or return air filter (heating). Replace filter.
Dirty outdoor coil (cooling). Clean coil.
Refrigerant overcharged. Recover excess refrigerant.
Air in system. Recover refrigerant, evacuate system, and recharge.
Condensing air restricted or air short-cycling. Determine cause and correct.
Low refrigerant charge. Check for leaks; repair and recharge.
Compressor scroll plates defective. Replace compressor.
Restriction in liquid tube. Remove restriction.
High heat load. Check for source and eliminate.
Compressor scroll plates defective. Replace compressor.
Refrigerant overcharged. Recover excess refrigerant.
Dirty air filter (cooling). Replace filter.
Dirty or heavily iced outdoor coil (heating). Clean outdoor coil. Check defrost cycle operation.
Low refrigerant charge. Check for leaks; repair and recharge.
Metering device or low side restricted. Remove source of restriction.
Insufficient indoor airflow (cooling mode). Increase air quantity. Check filter and replace if necessary.
Temperature too low in conditioned area. Reset thermostat.
Field-installed filter drier restricted. Replace.
Outdoor ambient below 25°F (cooling). Install low?ambient kit.
Outdoor fan motor(s) not operating (heating). Check fan motor operation.

Replace component.

Check wiring and repair or replace.

Determine cause. Replace compressor or allow enough time for
internal overload to cool and reset.

Determine cause and replace compressor.

Determine cause and replace.

Replace.

Start-Up.

32

APPENDIX A

AIR CONDITIONER AND HEAT PUMP WITH
PURON

•Puron® (R-410A) refrigerant operates at 50 percent to

•Puron

• Recovery cylinder service pressure rating must be 400

•Puron

• Manifold sets should be 700 psig high side and 180 psig

• Use hoses with 700 psig service pressure rating.

• Leak detectors should be designed to detect HFC

•Puron

• Vacuum pumps will not remove moisture from oil.

• Use only factory specified liquid-line filter driers with

®

— QUICK REFERENCE GUIDE

70 percent higher pressures than R-22. Be sure that
servicing equipment and replacement components are
designed to operate with Puron

®

refrigerant cylinders are rose colored.

®

.

psig, DOT 4BA400 or DOT BW400.

®

systems should be charged with liquid
refrigerant. Use a commercial type metering device in
the manifold hose when charging into suction line with
compressor operating.

low side with 550 psig low-side retard.

refirgerant.

®

, as with other HFCs, is only compatible with
POE oils.

rated working pressures greater than 600 psig.

• 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.

• Wrap all filter driers and service valves with wet cloth
when brazing.

• A factory approved, liquid-line filter drier is required on
every unit.

• Do not use an R-22 TXV.

• If indoor unit is equipped with a TXV, it must be
changed to a Puron

®

TXV.

• 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.

• Always replace filter drier after opening system for
service.

• Do not vent Puron

®

into the atmosphere.

• Do not use capillary tube coils.

• Observe all warnings, cautions, and bold text.

•All Puron

• Do not leave Puron

®

heat pumps must have indoor TXV.

®

suction line driers in place for

more than 72 hours.

APPENDIX B

WIRING DIAGRAM LIST

38AUQ

Size Electrical Characteristics Diagram Number
*07 208/230-3-60 38AU500363

460-3-60 38AU500362
575-3-60 38AU500435

*08 208/230-3-60 38AU500363

460-3-60 38AU500362
575-3-60 38AU500435

*12 208/230-3-60 38AU500363

460-3-60 38AU500362
575-3-60 38AU500435

33

APPENDIX C

MOTORMASTER SENSOR LOCATIONS

MOTOR MASTER SENSOR

MUST BE POSITIONED

BETWEEN METERING DEVICE

(SECOND FROM TOP)

AND TUBE SHEET

6T HEAT PUMP

MOTOR MASTER SENSOR

MUST BE POSITIONED

ON VAPOR STUB

(FOURTH FROM TOP)

7.5T HEAT PUMP

MOTOR MASTER SENSOR

MUST BE POSITIONED

ON VAPOR STUB

(FOURTH FROM TOP)

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.
INDOOR: AIR HANDLER MANUFACTURER

MODEL NO. SERIAL NO.

ADDITIONAL ACCESSORIES

II. PRE-START-UP

OUTDOOR UNIT

IS THERE ANY SHIPPING DAMAGE?
IF SO, WHERE:

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? (Y/N)
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY? (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? (Y/N)
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? (Y/N)
ARE PROPER AIR FILTERS IN PLACE? (Y/N)
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT? (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? (Y/N)
HAVE SUCTION SERVICE VALVES BEEN OPENED? (Y/N)

CHECK VOLTAGE IMBALANCE

LINE-TO-LINE VOLTS: AB
(AB + AC + BC)/3 = AVERAGE VOLTAGE =
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE = 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.

VAC VBCV

V

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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