Installation guide

ManualsBrandsCarrier ManualsHeating & cooling combined unitOfficial Carrier heat pump

wireY)andECMboard(throughunitwireG)

acrossthe24-v.secondaryoftransformer(TRAN).

ThermidistatorThermostatandHumidistat:

Whentheroomtemperaturerisestoapointthatis

slightlyabovethecoolingcontrolsettingofthe

thermostat,thethermostatcompletesthecircuit

betweenthermostatterminalRtoterminalsY,O,

DH,andG.Thesecompletedcircuitsthroughthe

thermostatconnectcontactorcoil(C)(throughunit

wireY)andECMboard(thoughunitwireG)

acrossthe24-v.secondaryoftransformer

(TRANS).

(3.)PlacesystemswitchorMODEcontrolinHEAT

position.Setcontrolaboveroomtemperature.

Observethatcompressor,outdoorfan,andindoor

blowermotorsstart.Observethatheatingcycle

shutsdownaccordingtotimedelayselectedonthe

EasySelectboard(SeeEasySelectSection)when

controlsettingissatisfied.

(4.)Whenusinganautomaticchangeoverroom

thermostatplacebothSYSTEMorMODEcontrol

andFANmodeswitchesinAUTOpositions.

ObservethatunitoperatesinCoolingmodewhen

temperaturecontrolissetto"callforCooling"

(belowroomtemperature),andunitoperatesin

Heatingmodewhentemperaturecontrolissetto

"callforHeating"(aboveroomtemperature).

NOTE:Oncethecompressorhasstartedandthenhasstopped,it

shouldnotbestartedagainuntil5 minutes have elapsed. The

cooling cycle remains "on" until the room temperature drops to

point that is slightly below the cooling control setting of the room

thermostat. At this point, the thermostat "breaks" the circuit

between thermostat terminal R to terminals Y and G. These open

circuits de-energize contactor coil C and ECM board. The

condenser and compressor motors stop. After the time delay setting

selected on the Easy Select board (See Easy Select Section) , the

blower motor stops. The unit is in a "standby" condition, waiting

for the next "call for cooling" from the room thermostat. The 5

minute compressor delay also applies to heat pump heating mode.

Step 2 -- Check for Refrigerant Leaks

Locate and repair refrigerant leaks and charge the unit as follows:

1. 1. Use both high- and low-pressure ports to relieve system

pressure and reclaim remaining refrigerant.

2. Repair leak following accepted practices.

NOTE: Install a bi-flow filter drier whenever the system has been

opened for repair.

3. Check system for leaks using an approved method.

4. Evacuate refrigerant system and reclaim refrigerant if no

additional leaks are found.

5. Charge unit with R-410A refrigerant, using a

volumetriccharging cylinder or accurate scale. Refer to unit

rating plate for required charge.

Step 3 -- Start-Up Adjustments

Complete the required procedures given in the Pre-Start-Up

section before starting the unit. Do not jumper any safety devices

when operating the unit. Do not operate the unit in Cooling mode

when the outdoor temperature is below 40°F (4°C) (unless

accessory low-ambient kit is installed). Do not rapid-cycle the

compressor. Allow 5 rain. between "on" cycles to prevent

compressor damage.

CHECKING COOLING AND HEATING CONTROL

OPERATION

Start and check the unit for proper control operation as follows:

1. Place room thermostat SYSTEM switch or MODE control

in OFF position. Observe that blower motor starts when

FAN mode is placed in FAN ON position and shuts down

within 60 sec (030-060 size) or 30 sec (024 size) when

FAN MODE switch is placed in AUTO position.

2. Place system switch or MODE control in HEAT position.

Set control above room temperature. Observe that

compressor, outdoor fan, and indoor blower motors start.

Observe that heating cycle shuts down when control setting

is satisfied.

LEGEND

OUTDOORCOIL

I-"

1-"

Bypass

Position

TXV in Meterin(

Position

r-q

LCS

NNDOOR COIL

HPS - High Pressure Switch

LCS - Loss of Charge Switch

_ _ _i}_Accuratet_Metering Device

f}-] Arrow indicates direction of flow

Fig. 23 - Typical Heat Pump Operation, Cooling Mode

C03011