Hussmann Ingersoll Rand User Manual page 251

Troubleshooting - Motor Burnout (Clean-up Procedure)
When a hermetic motor burns out, the stator winding decomposes forming carbon, water,
and acid, which contaminate refrigerant systems. These contaminants must be removed
from the system to prevent repeat motor failures.
Warning! Before attempting any service work on the compressor, see safety
precautions listed on page 12 of this section. Failure to follow these instructions could
result in serious personal injury.
a. Determine cause of burnout and make any necessary corrections. Check control box
for blown fuses, welded starter contacts, welded overload contacts or burned out
heater elements. Check compressor terminal plate for burned or damaged terminals
and insulation, also check for shorted or grounded terminals. Check unit wiring for
loose power connections. Check for high or low voltage.
b. Close compressor suction and discharge service valves and bleed refrigerant from
compressor. Save remaining refrigerant in system.
c. Remove suction and discharge service valves and all other connections from the
damaged compressor. Remove damaged compressor and replace with a new
compressor. On severe motor burnouts, be sure shut-off valves and suction or
discharge lines are not contaminated. If they are, they should be thoroughly cleaned
or replaced before connecting to replacement compressor.
d. Install new liquid line filter-drier and if the system has a suction line filter-drier, also
replace that core.
e. Evacuate and dehydrate replacement compressor and check to see that oil in
compressor is at proper level.
f. Place compressor in operation. After 2-4 hours of operation, check compressor oil for
discoloration and/or acidity. If oil shows signs of contamination, replace oil charge,
replace filter-driers, and clean suction strainer.
g. Check oil daily for discoloration and acidity. If oil stays clean and acid-free, the
system is clean. If oil shows signs of contamination, change oil, change filter-drier,
and clean suction strainer. If filter-drier or strainer is dirty or discolored, repeat this
step until system is cleaned.
Installation and Start-up 17