Troubleshooting - North Star M459231B.1 Installation, Operation And Maintenance Manual

This section provides a list of the more frequently encountered compressor malfunctions, their
causes and corrective actions. Some corrective actions can be performed by the operator or
maintenance personnel, and others may require assistance of a qualified electrician or Service
Center.
PROBLEM
Motor does not turn.
Motor overload trips or draws excessive current.
Excessive noise, vibration, knocking or rattling.
Lights flicker or dim when running.
Air delivery drops off.
Compressor does not come up to speed.
Compressor is slow to come up to speed.
Compressor will not unload cycle.
Compressor will not unload when stopped.
Excessive starting or stopping.
Moisture in crankcase, "milky" substance in oil.
Oil in discharge air.
Safety/relief valve "pops".
Low interstage pressure.
High interstage pressure.
POSSIBLE CAUSE
A.) Circuit breaker on motor tripped.
B.) Supply line circuit breaker tripped.
C.) Wiring or electric service panel too small.
D.) Compressor wired incorrectly.
E.) Poor contact on motor terminals or starter connections
F.) Compressor viscosity too high for ambient temperature.
G.) Poor ground.
H.) Belt tension too tight or sheaves not aligned.
I.) Air leaks in discharge piping.
J.) Poor power regulation.
K.) Compressor components leaky, broken, loose.
L.) Loose flywheel or motor pulley, excessive end play in motor shaft
or loose drive belts.
M.) Leaking check valve or check valve seat blown out.
N.) Clogged or dirty inlet and/or discharge line.
O.) Defective safety/relief valve.
P.) Pressure switch unloader leaks or does not work.
Q.) Inadequate ventilation around flywheel.
R.) Leaking, broken or worn inlet unloader parts at check valve.
S.) Excessive condensation in receiver tank.
T.) Detergent lubricant/water in crankcase.
U.) Light duty cycle.
V.) Lubricant level too high.
W.) Worn cylinder finish.
X.) Low pressure inlet valve leaking.
Y.) High pressure inlet valve leaking.

Troubleshooting

POSSIBLE SOLUTION
Push button located on back of motor.
Reset circuit breaker.
Install properly sized wire or service box. Contact electrician.
Check wiring, contact electrician.
Ensure good contact on motor terminals or starter connections.
Drain existing lubricant and refill with proper lubricant.
Check all ground connections.
Check tension/alignment.
Check tubing connections, Tighten joints or replace as required.
Contact power company.
Inspect components. Clean or replace as required.
Check flywheel, motor pulley, crankshaft drive belt tension/alignment.
Replace or repair as required.
Replace check valve.
Clean or replace.
Replace.
Replace.
Relocate compressor for better air flow.
Inspect parts and replace as required.
Drain receiver tank.
Replace with proper lubricant.
Increase duty cycle.
Drain excess lubricant.
Deglaze cylinder with 180 grit flex-hone.
Inspect, clean or repair as required.
Inspect, clean or repair as required.
12
POSSIBLE CAUSE
A, B, C, D, E
D, G, M
H, I, K, L, N, O, P, R, W
C, D, E, J, M
I, P, L, M, N, O, P, R, W, X, Y
C, D, F, H, L, M, P
C, D, F, H, L, M, N
I, N, P, R
I, N, P, R
D, E, G, P, S, U
T
V
N, O, P
Y
X