Carrier Heat Pump 38YCX User Manual

38YCX—50 Hz

Heat Pump—Outdoor Section

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Installation and Start-Up Instructions

NOTE: Read the entire instruction manual before starting the

installation.

This symbol → indicates a change since the last issue.

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 pack-

aged with the kits or accessories when installing.

IP24

Follow all safety codes. Wear safety glasses and work gloves. Use

quenching cloth for brazing operations. Have fire extinguisher

available. Read these instructions thoroughly and follow all

warnings or cautions attached to the unit. Consult local building

codes and the national electric codes for special installation

requirements.

Recognize safety information. This is the safety-alert symbol

When you see this symbol on the unit or in instructions and

manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, and CAU-

TION. These words are used with the safety-alert symbol. DAN-

GER 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 would 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.

A97005

Fig. 1—Model 38YCX

When installing, allow sufficient space for airflow clearance,

wiring, refrigerant piping, and service. Allow 30-in. (762mm)

clearance to service end of unit and 48 in. (1219mm) above unit.

For proper airflow, a 6-in. (152mm) clearance on 1 side of unit and

12 in. (305mm) on all remaining sides must be maintained.

Maintain a distance of 24 in. (610mm) between units. Position so

water, snow, or ice from roof or eaves cannot fall directly on unit.

Before installing, modifying, or servicing system, main elec-

trical disconnect switch must be in the OFF position. There

may be more than 1 disconnect switch. Lock out and tag

switch with a suitable warning label. Electrical shock can

cause personal injury or death.

On rooftop applications, locate unit at least 6 in. (152mm) above

roof surface. Place unit above a load-bearing wall and isolate unit

and tubing set from structure.

Arrange supporting members to adequately support unit and

minimize transmission of vibration to building. Consult local

codes governing rooftop applications.

INSTALLATION

Step 1—Check Equipment and Job Site

Step 3—Elevate Unit

UNPACK UNIT — Move to final location. Remove carton taking

care not to damage unit.

INSPECT EQUIPMENT — File claim with shipping company

prior to installation if shipment is damaged or incomplete. Locate

unit rating plate on unit corner panel. (See Fig. 2.) It contains

information needed to properly install unit. Check rating plate to

be sure unit matches job specifications.

Accumulation of water and ice in base pan may cause

equipment damage.

In areas where prolonged freezing temperatures are encountered,

elevate unit per local climate and code requirements to provide

clearance above estimated snowfall level and ensure adequate

drainage of unit. (See Fig. 3.)

Step 2—Install on a Solid, Level Mounting Pad

If conditions or local codes require the unit be attached to pad, tie

down bolts should be used and fastened through knockouts

provided in unit base pan. Refer to unit mounting pattern in Fig. 2

to determine base pan size and knockout hole location.

Step 4—Replace Indoor AccuRater® Piston (if required)

Check indoor coil piston to see if it matches the required piston

shown on outdoor unit rating plate. (See Fig. 2.) If it does not

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book

Tab 5a 5a

PC 101

Catalog No. 003-880

Printed in U.S.A.

Form 38YCX-C3SI

Pg 1

2-02

Replaces: 38YCX-C2SI

Table 1—Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters

LIQUID

VAPOR

UNIT SIZE

Connection Dia.

In. mm

Tube Dia.

Connection DIia.

Vapor Dia.

In.

3/8

In.

5/8

024

036

048

060

3/8

9.53

5/8

3/4

7/8

15.88

19.05

22.23

15.88

19.05

22.23

28.58

3/4

7/8

1-1/8

NOTES: 1. Tube diameters are for lengths up to 50 ft (15.24m). For tubing lengths greater than 50 ft (15.24m), consult Long-Line Application Guideline.

2. Do not apply capillary tube indoor coils to these units.

NOTE:Avoid contact between tubing and structure.

OUTDOOR WALL

CAULK

INDOOR WALL

To prevent compressor damage DO NOT bury more than 36

in. of refrigerant tubing. If ANY tubing is buried, provide 6

in. vertical rise at service valve.

LIQUID TUBE

To prevent damage to unit or service valves observe the

following:

• Use a brazing shield.

• Wrap service valves with wet cloth or use a heat sink

material.

VAPOR TUBE

JOIST

INSULATION

THROUGH THE WALL

Outdoor units may be connected to indoor section using accessory

tubing package or field-supplied refrigerant grade tubing of correct

size and condition. For tubing requirements beyond 50 ft (15.24m),

consult Long-Line Application Guideline which is available from

your local distributor.

HANGER STRAP

(AROUND VAPOR

TUBE ONLY)

INSULATION

VAPOR TUBE

NOTE: In some cases noise in the living area has been traced to

gas pulsations from improper installation of equipment.

INSTALLATION RECOMMENDATIONS

1. Locate unit away from windows.

1″ MIN

2. Ensure that vapor and liquid tube diameters are appropriate to

capacity of unit. (See Table 1.)

(25 mm)

LIQUID TUBE

SUSPENSION

3. Run refrigerant tubes as directly as possible by avoiding

unnecessary turns and bends.

A94330

4. Leave some slack between structure and unit to absorb

vibration.

Fig. 4—Piping Installation

5. When passing refrigerant tubes through the wall, seal opening

with RTV or other pliable silicon-based caulk. (See Fig. 4.)

PISTON BODY

6. Avoid direct tubing contact with water pipes, ductwork, floor

joists, wall studs, floors, and walls.

7. Do not suspend refrigerant tubing from joists and studs with a

rigid wire or strap which comes in direct contact with tubing.

(See Fig. 4.)

8. Ensure that tubing insulation is pliable and completely sur-

rounds vapor tube.

PISTON

9. When necessary, use hangar straps which are 1 in. (25mm)

wide and conform to shape of tubing insulation. (See Fig. 4.)

PISTON RETAINER

10. Isolate hangar straps from insulation by using metal sleeves

bent to conform to shape of insulation.

SWEAT/FLARE ADAPTER

If refrigerant tubes or indoor coil is exposed to atmosphere, it must

be evacuated to 500 microns to eliminate contamination and

moisture in the system.

A94029

Fig. 5—Service Valve with Sweat Adapter Tube

OUTDOOR UNIT CONNECTED TO FACTORY-APPROVED

INDOOR UNIT — Outdoor unit contains correct system refriger-

ant charge for operation with indoor unit of same size when

connected by 15 ft (4.55m) of field-supplied or factory-accessory

tubing. Check refrigerant charge for maximum efficiency.

REFRIGERANT TUBING — Connect tubing to fittings on out-

door unit vapor and liquid service valves. (See Fig. 2 and 5.)

The unit cabinet must have an uninterrupted or unbroken

ground to minimize personal injury if an electrical fault

should occur. The ground may consist of electrical wire or

metal conduit when installed in accordance with existing

electrical codes. Failure to follow this warning can result in an

electric shock, fire, or death.

SWEAT CONNECTION — Use refrigerant grade tubing. Service

valves are closed from factory and ready for brazing. After

wrapping service valve with a wet cloth, tubing set can be brazed

to service valve using either silver bearing or non-silver bearing

brazing material. Consult local code requirements. Refrigerant

tubing and indoor coil are now ready for leak testing. This check

should include all field and factory joints.

NOTE: Use No. 18 AWG (American Wire Gage) color-coded,

insulated (35°C minimum) wires. If thermostat is located more

than 100 ft (30.5m) from unit (as measured along the control

voltage wires), use No. 16 AWG color-coded wires to avoid

excessive voltage drop.

Step 6—Make Electrical Connections

To avoid personal injury or death, do not supply power to unit

with compressor terminal box cover removed.

CONNECT CONTROL WIRING — Route 24-v control wires

through control wiring grommet and connect leads to control

wiring terminal board. (See Fig. 7.)

Be sure field wiring complies with local and national fire, safety,

and electrical codes, and voltage to system is within limits shown

on unit rating plate. Contact local power company for correction of

improper voltage. See unit rating plate for recommended circuit

protection device.

Use furnace transformer, fan coil transformer, or accessory trans-

former for control power, 24-v/40-va minimum.

NOTE: Use of available 24-v accessories may exceed the mini-

mum 40-va power requirement. Determine total transformer load-

ing and increase the transformer capacity or split the load with an

accessory transformer as required.

NOTE: Operation of unit on improper line voltage constitutes

abuse and could affect unit reliability. See unit rating plate. Do not

install unit in system where voltage may fluctuate above or below

permissible limits.

NOTE: The defrost timer is factory set for 90-minute cycles. The

timer can be field set for 30- and 50-minute cycles depending on

defrost conditions in your geographic location.

NOTE: Use copper wire only between disconnect switch and

unit.

Step 7—Compressor Crankcase Heater

NOTE: Install branch circuit disconnect per local codes to handle

unit starting current. Locate disconnect within sight from and

readily accessible from unit per local codes.

When equipped with a crankcase heater, energize heater a mini-

mum of 24 hr before starting unit. To energize heater only, set

thermostat to OFF and close electrical disconnect to outdoor unit.

ROUTE GROUND AND POWER WIRES — Remove access

panel and control box cover to gain access to unit wiring. Extend

wires from disconnect through power wiring hole provided and

into unit control box. (See Fig. 2.) Size wires per local codes but

not smaller than minimum wire size shown on unit rating plate.

A crankcase heater is required if the refrigerant tubing is longer

than 50 ft.

Step 8—Install Electrical Accessories

Refer to the individual instructions packaged with the kits or

accessories when installing.

CONNECT GROUND AND POWER WIRES — Connect ground

wire to ground connection in control box for safety. Connect

power wiring to contactor as shown in Fig. 6.

Step 9—Start-up and Check Charge

DISCONNECT PER

IEC AND/OR

To prevent compressor damage or personal injury, observe

the following:

• Do not overcharge system with refrigerant.

• Do not operate unit in a vacuum or at negative pressure.

• Do not disable low-pressure switch

In scroll compressor applications:

LOCAL CODES

FIELD POWER

CONTACTOR

WIRING

L2/N

N FOR 1-PHASE ONLY

3-PHASE ONLY

• Dome temperatures may be hot.

L2/N

To prevent personal injury wear safety glasses, protective

clothing, and gloves when handling refrigerant and observe

the following:

• Back seating service valves are not equipped with Schrader

valves. Fully back seat (counter clockwise) valve stem before

removing gage port cap.

GROUND

LUG

• Front seating service valves are equipped with Schrader

valves.

A96650

Fig. 6—Line Power Connections

FB4ASX

HEAT PUMP

FAN COIL

THERMOSTAT

ODTS

BLU

SYSTEMS WITH ONE

OUTDOOR THERMOSTAT

SYSTEMS WITHOUT

OUTDOOR THERMOSTAT

A97053

A97054

FB4ASX

FAN COIL

THERMOSTAT

HEAT PUMP

ODTS1

BLU

VIO

ODTS2

EMERGENCY HEAT RELAY

SYSTEMS WITH TWO

OUTDOOR THERMOSTATS

A97052

Fig. 7—24-v Control Circuit Connections

Do not vent refrigerant to atmosphere. Recover during system

repair or final unit disposal.

1. If equipped with a crankcase heater, energize a minimum of

24 hr before starting unit. To energize heater only, set

thermostat OFF and close electrical disconnect to outdoor

unit.

2. Fully open liquid and vapor service valves.

3. Unit is shipped with valve stem(s) front seated and caps

installed. Replace stem caps after system is opened to refrig-

erant flow. Replace caps finger tight and tighten additional 1/6

turn using a backup wrench on valve body flats to prevent

distortion of sheet metal.

A00010

Fig. 8—Phase Monitor Control

4. Close electrical disconnects to energize system.

5. Set room thermostat at desired temperature.

Table 2—Phase Monitor LED Indicators

LED

OFF

STATUS

6. Set room thermostat to HEAT or COOL and fan to ON or

AUTO mode, as desired. Operate unit for 15 minutes. Check

system refrigerant charge.

No call for compressor

operation

FLASHING

Reversed phase

Normal

7. Factory charge is shown on unit rating plate. Adjust charge in

cooling mode by following procedure shown in charging

table. Check charge in heating mode by following procedure

shown on heating check chart. Both are located on unit.

Should the temperature continue to fall, R-W2 is made through the

second-stage room thermostat bulb. Circuit R-W2 energizes a

sequencer, bringing on the first bank supplemental electric heat

and providing electrical potential to the second heater sequencer (if

used). If outdoor temperature falls below the setting of the outdoor

thermostat (field-installed option), contacts close to complete the

circuit and bring on the second bank of supplemental electric heat.

• 3-phase scroll compressors are rotation sensitive.

• A flashing LED on phase monitor indicates reverse rotation.

(See Fig. 8 and Table 2.)

• This will not allow contactor to be energized.

• Disconnect power to unit and interchange 2 field wiring

leads on unit contactor.

When the thermostat is satisfied, its contacts open, de-energizing

contactor and sequencer. All heaters and motors should stop.

→ ^{Quiet Shift}

SEQUENCE OF OPERATION — With power supplied to indoor

and outdoor units, transformer is energized. Defrost control board

is equipped with 5-minute lockout timer which may be initiated

upon any interruption of power.

Quiet Shift is a field-selectable defrost mode, which will eliminate

occasional noise that could be heard at the start of the defrost cycle

and restarting of heating cycle. It is selected by placing DIP switch

3 (on defrost board) in ON position.

Cooling

When Quiet Shift switch is placed in ON position, and a defrost is

initiated, the following sequence of operation will occur. Revers-

ing valve will energize, compressor will turn off for 30 sec, then

turn back on to complete defrost. At the start of heating cycle after

conclusion of defrost mode, reversing valve will de-energize, the

compressor will turn off for another 30 sec, and the fan will turn

off for 40 sec, before starting in the heating mode.

On a call for cooling, the thermostat makes circuits R-O, R-Y, and

R-G. Circuit R-O energizes reversing valve, switching it to cooling

position. On three phase models with scroll compressors, the units

are equipped with a phase monitor to detect if the incoming power

is correctly phased for compressor operation. (See Fig. 8 and Table

2.) If phasing is correct, circuit R-Y energizes contactor, starting

outdoor fan motor and compressor circuit. R-G energizes indoor

unit blower relay, starting indoor blower motor on high speed.

→ ^Defrost

The defrost control is a time/temperature control which includes a

field-selectable time period (DIP switch 1 and 2 on the board)

between defrost cycles of 30, 60, 90, or 120 minutes (factory set at

90 minutes).

NOTE: If the phasing is incorrect, the contactor will not be

energized. To correct the phasing, interchange any two of the three

power connections on the field side.

When thermostat is satisfied, its contacts open, de-energizing

contactor and blower relay. Compressor and motors stop.

To initiate a forced defrost, two options are available depending on

the status of the defrost thermostat.

NOTE: If indoor unit is equipped with a time-delay relay circuit,

the blower runs an additional 90 sec to increase system efficiency.

If defrost thermostat is closed, speedup pins (J1) must be shorted

by placing a flat head screwdriver in between for 5 sec and

releasing, to observe a complete defrost cycle. When the Quiet

Shift switch is selected, compressor will be turned off for two 30

sec intervals during this complete defrost cycle as explained

previously. When Quiet Shift switch is in factory default OFF

position, a normal and complete defrost cycle will be observed.

Heating

On a call for heating, the thermostat makes circuits R-Y and R-G.

If phasing is correct, circuit R-Y energizes contactor, starting

outdoor fan motor and compressor. Circuit R-G energizes indoor

blower relay, starting blower motor on high speed.

If defrost thermostat is in open position, and speedup pins are

shorted (with a flat head screwdriver) for 5 sec and released, a

short defrost cycle will be observed (actual length is dependent

upon the selected Quiet Shift position). When Quiet Shift switch is

in ON position, the length of defrost is 1 minute (30 sec

compressor off period followed by 30 sec of defrost with com-

pressor operation). On return to heating operation, compressor will

again turn off for an additional 30 sec and the fan for 40 sec. When

the Quiet Shift is in OFF position, only a brief 30 sec cycle will be

observed.

If it is desirable to observe a complete defrost in warmer weather,

the thermostat must be closed as follows:

1. Turn off power to outdoor unit.

CESO130076–00

2. Disconnect outdoor fan motor lead from OF2 on control board

(See Fig. 9.) Tape to prevent grounding.

Speedup

Pins

Quiet

Shift

Defrost interval

DIP switches

A99442

3. Restart unit in heating mode, allowing frost to accumulate on

outdoor coil.

Fig. 9—Defrost Control

CARE AND MAINTENANCE

4. After a few minutes in heating mode, liquid line temperature

should drop below closing point of defrost thermostat (ap-

proximately 30°F).

For continuing high performance and to minimize possible equip-

ment failure, periodic maintenance must be performed on this

equipment.

NOTE: Unit will remain in defrost until defrost thermostat

reopens at approximately 80°F coil temperature at liquid line or

remainder of defrost cycle time.

Leave User’s Manual with owner. Explain system operation and

periodic maintenance requirements outlined in manual. Frequency

of maintenance may vary depending upon geographic areas, such

as coastal applications.

5. Turn off power to outdoor and reconnect fan motor lead to

OF2 on control board after above forced defrost cycle.

38ycxc3si