Troubleshooting Chart - Jet JCP-803 Operating Instructions And Parts Manual

TROUBLESHOOTING CHART

Symptom Possible Cause(s)
Motor hums and runs 1. Low voltage or no voltage
slowly or not at all
2. Shorted or open motor winding
3. Malfunctioning check valve or
unloader valve
4. Malfunctioning pressure switch -
contacts will not close
Reset mechanism 1. Pressure switch set too high
cuts out repeatedly or
2. Malfunctioning check valve
fuses blow repeatedly
3. Incorrect fuse size or magnetic starter
heaters
4. Malfunctioning motor
5. Loose Wiring
Excessive noise in 1. Loose pulley, flywheel, belt, belt
operation guard, etc
2. Lack of oil in crankcase
3. Compressor floor mounting loose
4. Malfunctioning check valve
5. Unit not on vibration pads
Milky oil in oil 1. Low usage of compressor - water is
crankcase condensing in the crankcase
2. Wrong type of oil
3. Improper environment
4. Rotation incorrect
5. Slight leakage of tank check valve
Excessive oil 1. Be sure there is a problem
consumption or oil in
air lines
2. Restricted air intake
3. Wrong oil viscosity
4. Worn piston rings
5. Oil leaks
6. Scored cylinder
Water in discharge air 1. Excessive water in tank
2. Hot, humid weather
Air blowing out of inlet 1. Broken first stage inlet valve (two-
stage unit)
2. Broken inlet valve (single stage unit)
Insufficient pressure 1. Air demand too high
2. Leaks or restrictions in hoses or
piping
3. Slipping belts
Tank does not hold 1. Worn check valve
pressure when
compressor is off and
shutoff valve is closed
2. Check all connections and fittings for
tightness
3. Check tank for cracks or pin holes
12
Corrective Action
1. Check with voltmeter, check overload relay in magnetic starter or reset
switch on motor. If overload or reset switch trips repeatedly, find and
correct the cause. See next item
2. Replace motor
3. Replace check valve or unloader valve
4. Repair or replace pressure switch
1. Replace pressure switch
2. Clean or replace faulty valve
3. Be sure that fuses and heaters are rated properly
4. Replace motor
5. Check all electrical connections
1. Tighten
2. Check for damage to bearings, replenish oil
3. Shim to level and tighten or place on islolator pads
4. Replace check valve
5. Install vibration pads under compressor feet
1. Run the compressor continuously for 1 hour. The heat generated during
this running period will evaporate the moisture out of the oil
2. Do not use SAE-30 automotive type oil. Using the wrong oil can cause
various problems with the pump and will void the warranty. Only use the
oils that the operating manual recommends
3. Unit should not be installed in a poorly vented area or exposed to
extreme cold or hot conditions. Normal operating range should be
between 32°F and 100°F
4. Check to make sure the compressor is running the direction of the
flywheel arrow. Air flow should be so that the flywheel directs air across
the head of the pump. Standing in front of the compressor (non-belt
guard side) air should flow back to front
5. Air cools and condensates, then leaks back into the pump. Draining tank
of air after use will normally take care of this situation
1. Diagnose oil contamination problems by testing the discharge air or
measuring oil consumption from the crankcase
2. Clean or replace air filter
3. Drain oil. Refill with oil of proper viscosity
4. Replace rings
5. Tighten bolts, replace gaskets or o-rings
6. Replace cylinder
1. Drain tank
2. Purchase dryer
1. Replace valve assembly
2. Replace valve assembly
1. Limit air usage
2. Check for leaks or restriction in hose or piping
3. Tighten belts
1. Replace check valve
Do not disassemble check valve with air
in tank
2. Tighten
3. Replace tank. Never repair a damaged tank