Hussmann Ingersoll Rand, User Manual

Page: 248 / 346

Installation and Start-up 14
Observation Possible Cause Remedy
Excessive water flow
through condenser Adjust water regulating valve
Suction service valve
partially closed Open the valve
Leaky compressor suction
valves Pump down, remove the
cylinder head, examine valves
and seats; replace if necessary
6. Low discharge pressure
Worn piston rings Replace compressor
Improper system piping
allows liquid to compressor Correct piping
Defrost cycle improperly
set or not operating
correctly Do not allow more than 1/3 of
the system to be on defrost at
any given time. Check operation
of defrost system.
Defective or improperly set
expansion valve Increase superheat or replace
valve
7. Flooding
Evaporator fan failure Correct problem or replace fan
Insufficient refrigerant in
system Add refrigerant
Evaporator fan failure Correct problem or replace fan
8. Low suction pressure
Plugged filter drier Replace filter
Slugging due to flood back
of refrigerant See No. 7 (Flooding)
Hydraulic knock due to
excess oil in circulation a. Remove excess oil
b. Recheck oil return system
Bearings wiped because of
loss of oil a. Add oil
b. Check oil return system
c. See No. 15 (Oil return) and
No.11 (Oil pressure)
d. Check for defective oil
failure control
Improper support or
isolation of piping Provide sufficient right angle
bends in piping to absorb
vibration and support firmly
with suitable hangers
Compressor not firmly
mounted Check for loose mounts
Unit not properly isolated
or vibration pad defective Add vibration isolation or check
for defection isolation pads
9. Compressor noisy
Broken connecting rods,
valves, or running gear Replace compressor