Carrier 50LJ User Manual download pdf (Page 34)

a. Disconnect CLO sensor wires connected to CL02 at

the control board. Check wires for continuity. If there

is no continuity, replace the sensor.

b. Connect the multimeter to read voltage between Pin

X on plug PI and ground.

c. Turn unit power on and check the multimeter. Within

a few seconds the meter should indicate 24 v. If it

does not, the control board is defective and must be

replaced.

d. Turn unit power off. Connect a fresh 1.5-v battery to

terminal marked CL02 as shown in Fig. 34.

8. To verify compressor lockout logic;

A CAUTION

The negative (-Ve) pole of the battery must be

connected to the inner terminal and the positive (+ Ve)

pole must be connected to the outer terminal as shown

in Fig. 34

e. Turn unit power on. Make and break the connection

between the outer CL02 terminal and the positive

( + Ve) pole of the battery.

f. If the multimeter shows 24 v when the battery is dis

connected and no voltage when the battery is con

nected, the CLO logic is good. If the multimeter shows

no change, the CLO logic is defective and the board

must be replaced. Remove all jumpers and replace all

plugs except plug PI. (Replace plug PI only if no

further troubleshooting is required.)

Symptom: First or Second Stage of Heating Will Not

Operate.

1. Turn unit power off. Disconnect plugs PI and P3.

2. Check continuity between Pin W1 at plug PI and Pin 5

at plug P3. If there is continuity, the board is good and

the problem is either the connection at P3, or external to

the control board. If there is continuity, the control board

is defective and must be replaced.

3. Check continuity between Pin W2 at plug PI and Pin 7

at plug P3. If there is continuity, the board is good and

the problem is either at the connection at plug P3 or ex

ternal to the board. If there is no continuity, the board is

defective and must be replaced. Reconnect plug P3 to

the control board. (Reconnect plug PI only if no further

troubleshooting is required.)

Symptom: Evaporator Fan Will Not Energize On a Call

For Heat.

1. Turn unit power off. Disconnect plug PI and plug P4.

2. Install jumper wire between Pin R and Pin W1 at plug

PI.

3. Turn unit power on. Check for continuity between Pin 6

and Pin 3 at plug P4 on control board.

4. If there is no continuity between these points, the board

is defective and must be replaced.

NOTE: The control board (part number HK37AA001)

has no time delay.

5. If there is continuity between these points, the problem

is at the connection at plug P4 or external to the control

board.

6. Turn unit power off. Reconnect plugs PI and P4.

ECONOMIZER BOARD CONTINUITY CHECK - The

economizer board is connection board that is used to inter

face the economizer circuit with the base unit and thermo

stat. There are no electronic components or logic built into

this board.

1. Disconnect plugs PI and P5 at the economizer control

board. Disconnect the harness going from the econo

mizer board to the unit control board.

2. Check continuity between points shown below. (See Fig.

35 for identification of points on the board.)

Pl-1 to P4-1

Pl-2 to P4-2

Pl-2 to P5-5

Pl-3 to P4-3

PI-4 to P5-2

P4-4 to P5-3

Pl-5 to P5-1

P4-5 to P5-4

PI-6 to P4-6

Pl-7 to P4-7

Pl-8 to P4-8

Pl-9 to P4-9

P4-10 to P5-6

3. If there is continuity between the above points, the econ

omizer board is good. Reconnect plugs PI and P5 to the

eeonomizer board and eonnect the economizer harness

to the unit control board.

If there is no continuity between the above points, the

economizer board is defective. Replace board.

1 2 ... 29 30 31 32 33 34 35 36 37 38

Comments to this Manuals

No comments

Carrier 50LJ User Manual Page 34

Comments to this Manuals

Related products and manuals for Conditioners Carrier 50LJ