Trouble

Probable Cause

Remedy

 

 

TROUBLESHOOTING COOLING UNIT REFRIGERATION SYSTEM

 

 

 

 

COMPRESSOR DOES NOT

A. Glycol (coolant) sufficiently

A. Refrigeration not called for.

OPERATE.

cooled.

 

 

B. Cooling Unit POWER switch in

B. Place Cooling Unit POWER

 

‘‘OFF’’ (down) position.

switch in ‘‘ON’’ (up) position.

C.No power source (blown fuse or tripped circuit breaker).

D.Low voltage.

C.Replace blown fuse or reset circuit breaker.

D.Voltage must be at least 103 VAC at compressor terminals when compressor is trying to start.

E.Loose, disconnected, or broken wiring.

F.Overload protector cut out; overheated compressor. Condenser fan motor not operating as required.

G.Inoperative overload protector or start relay.

H.Inoperative contactor.

I.Inoperative control board.

J.Evaporator or condenser outlet temperature sensor inoperative (open).

K.No voltage to control board.

E.Tighten connections or replace broken wiring.

F.Compressor will cool enough to restart. Refer to ‘‘CONDENSER FAN MOTOR NOT OPERATING’’ in this section;

G.Replace inoperative part.

H.Replace contactor.

I.Replace control board.

J.Replace inoperative temperature sensor.

K.Check for loose or broken wiring. Check transformer for 24 ± VAC output.

 

L.

Inoperative compressor.

L.

Replace compressor.

 

 

 

 

 

COMPRESSOR WILL NOT

A.

Glycol tank temperature

A.

Replace temperature control

STOP AFTER GLYCOL

 

control inoperative.

 

sensor.

(COOLANT) HAS BEEN

B.

Circuit board inoperative.

B.

Replace circuit board.

SUFFICIENTLY COOLED.

 

 

 

 

 

COMPRESSOR OPERATES

A.

Cooling Unit located in

A.

Refer to IMPORTANT note at

CONTINUOUSLY BUT DOES

 

excessively hot area.

 

start of SELECTING COOLING

NOT COOL GLYCOL

 

 

 

UNIT LOCATION in

(COOLANT) SUFFICIENTLY.

 

 

 

INSTALLATION SECTION.

 

B.

Air circulation through Cooling

B.

Clean air filter on back of Cooling

 

 

Unit restricted.

 

Unit as instructed.

 

 

 

 

 

CONDENSER FAN MOTOR

A. Jumper cord loose or

NOT OPERATING.

disconnected from condenser

 

fan motor or compressor

 

terminals. Broken wire in cord.

A.Tighten connections or replace cord.

B.

Fan blade obstructed.

B.

Remove obstruction.

C.

Inoperative condenser fan

C.

Replace condenser fan motor.

 

motor.

 

 

NOTE: If overload protector cuts out compressor,condenser fan motor will continue to operate; otherwise, troubleshooting condenser fan motor problems are same as for ‘‘COMPRESSOR DOES NOT OPERATE’’ paragraph plus the preceding:

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Cornelius 1550 Compressor does not, Operate, Compressor will not, Stop After Glycol, Coolant has Been, Sufficiently Cooled