Carrier 38TDB instruction manual Start-Up, A01192, A00430

Reversing Valve

Connection

Low/High Speed

Contactor Connection

SS0ID

HP/AC

C

SEV RVS

C

HI

LO

CEBD430439-03A

R38

C2

Low Pressure

J1

R33

R9

PL1

PL2

1

LPS

Switch Connector

R61

1

PL3

HPS

High Pressure

C31

Switch Connector

1

PL4

OAT

R65

DEFROST

FORCED

OCT

Thermistor

PL5

Connection

PWM2

DEFROST

Defrost Time 30

TIME (MIN)

60

R39

S1

120

R44

PWM1

R42

Selectors

60

1 2

30

C18

BRN

VC

R36

C16

To Run

90

BLU

0

VH

Capacitor

Y2

Thermostat

Y1

C O M M S T A T U S

BLK

ODF

W1

O.D.F. Connection

Low Voltage RC

D51

D52

CEPL130439-01

YEL

CCH L2

Connector

R85

R91

K1

RED

Crankcase Heater

R89

R86

R87

Connection

A

B

C D

H K 3 8 E A 0 0 1

Reserved for

Future Use

A01192

Fig. 12—Control Board

THERMISTOR CURVE

	90
(KOHMS)	80
	70
	60
RESISTANCE	50
	20
	40
	30

10

0

0 20 40 60 80 100 120

TEMPERATURE (DEG. F)

A91431

Fig. 13—Resistance Values Versus Temperature

Step 10—Start-Up

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.

Control Box

Side of Unit

THERMISTOR PLACED UNDERNEATH BASE PAN (ATTACHED TO BASE PAN WITH ADHESIVE)

A00430

Fig. 14—View from Top of Base Pan

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 (counterclockwise) valve stem before removing gage port cap.

Do not vent refrigerant to atmosphere. Recover during system repair or final unit disposal.

Follow these steps to properly start up the system:

1.The outdoor unit is equipped with a crankcase heater which operates when the compressor is off. Energize crankcase heater 24 hr before starting unit. To energize heater only, set indoor thermostat to OFF position and close power disconnect to unit.

NOTE: Starting the compressor without a minimum of 12 hr of crankcase heat prior to initial start-up, may result in a compressor chattering noise and possible damage to the compressor.

2.Fully back seat (open) liquid and vapor tube 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 (back seated). Replace caps finger tight and tighten additional 1/12 turn (20 ft-lb torque) with wrench.

4.Close electrical disconnects to energize system.

5.Set room thermostat at desired temperature. Be sure set point is below indoor ambient and is set low enough to energize desired speed.

NOTE: Carrier electronic thermostats are equipped with a 15- minute staging timer. This timer prevents the two-speed system from operating at high speed until unit has been operating in low speed for 15 minutes unless there is at least a 5°F difference between room temperature and thermostat set point. To force high speed (after a minimum of 2 minutes in low speed), adjust the set point at least 5° below room ambient.

6.Set room thermostat to COOL and fan control to AUTO or ON as desired. Wait for appropriate time delay(s). Operate unit for 15 minutes. Check refrigerant charge.

NOTE: If unit has not operated within the past 12 hr or following a unit power-up, upon the next thermostat high- or low-speed demand, unit operates for a minimum of 5 minutes in high speed.

10