Trouble Analysis - Trane CGA-SVX01A-EN Installation, Operation And Maintenance Manual

A. Compressor Neither Starts Nor Hums
Probable Cause
(1) No power to unit
(2) No call for cooling
(3) Compressor start delay (TR1,TR2) timer has not timed out time out
(4) Unit locked out by reset relay (CR)
(5) Compressor contactor will not close
(6) Compressor winding stat open
B. Compressor Hums, But Will Not Start
Probable Cause
(1) Low voltage at compressor
(2) Defective compressor
(3) Insufficient starting voltage (Single-Phase Units Only)

TROUBLE ANALYSIS

Check for followings:
a. Disconnect switch open
b. Fuse(s) blown
Check for followings:
a. Defective thermostat
b. Broken or improper control wiring
c. Blown control power fuse
Wait at least 2 minutes for the timer to time out
Check for the followings:
a. Excessive discharge pressure
b. Defective high pressure control
c. Low charge; Low pressure cut-out
d. Gate/water valve not open causing flow switch or anti-freeze
cutoff to trip
e. Fan motor internal temperature switch open
f . Defective reset relay contact
Check for the followings:
a. Defective compressor contactor
b. Improper wiring
c. Reset relay (CR) open
d. Low pressure cut-out open
Check compressor amp draw
Check for the followings:
a. Single blown fuse
b. Low line voltage
c. Defective compressor contactor
d. Loose wiring connections
Check for the followings:
a. Open motor winding
b. Excessive amp draw on all phases
Check for the followings:
a. Defective start capacitor
b. Defective start relay
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Recommended Action
Recommended Action
CGA-SVX01A-EN