Porter-Cable C7501M - Manual (Page 20)

20 - ENG N020206
TROUBLESHOOTING
Risk of Unsafe Operation. Unit cycles automatically when
power is on. When servicing, you may be exposed to voltage sources, com-
pressed air, or moving parts. Before servicing unit unplug or disconnect elec-
trical supply to the air compressor, bleed tank of pressure, and allow the air
compressor to cool.
PROBLEM CAUSE CORRECTION
Excessive
tank pressure
- safety valve
pops off
Pressure switch does
not shut off motor when
compressor reaches
"cut-out" pressure.
Move Auto/Off lever to the "Off"
position, if the unit does not shut off
contact a Trained Service Technician.
Pressure switch "cut-
out" too high.
Contact a Trained Service Technician.
Air leaks at
fittings
Tube fittings are not
tight enough.
Tighten fittings where air can be
heard escaping. Check fittings
with soapy water solution.
DO NOT OVER TIGHTEN.
Air leaks at
or inside
check valve
Check valve seat
damaged.
A defective check valve results in
a constant air leak at the pressure
release valve when there is pressure
in the tank and the compressor
is shut off. Replace check valve.
Refer the To Replace or Clean
Check Valve in the Service
and Adjustments section.
Air leaks at
pressure switch
release valve
Defective pressure
switch release valve.
Contact a Trained Service Technician.
Air leaks in air
tank or at air
tank welds
Defective air tank. Air tank must be replaced.
Do not repair the leak.
Risk of bursting.
Do not drill into, weld or otherwise
modify air tank or it will weaken.
The tank can rupture or explode.
Air leaks
between head
and valve plate
Leaking seal. Contact a Trained Service Technician.
Pressure
reading on
the regulated
pressure gauge
(if equipped)
drops when
an accessory
is used
It is normal for "some"
pressure drop to occur.
If there is an excessive amount of
pressure drop when the accessory
is used, adjust the regulator as
instructed in the Operation section.
NOTE: Adjust the regulated
pressure under flow conditions
(while accessory is being used).
Air leak from
safety valve
Possible defect in
safety valve.
Operate safety valve manually
by pulling on ring. If valve still
leaks, it should be replaced.