Fault Finding And Repair - Jun-Air 6-4 Modo De Empleo

FAULT FINDING AND REPAIR

Important!
Switch off and isolate from electrical supply before removing any
parts from the compressor.
Empty air receiver of air before dismantling any parts of
compressor unit's pressure system.
1. Compressor does not start:
a) No power from mains. Check fuses and plug.
b) Breakage or loose joints in electrical connections.
c) The starting relay is defective. Contact your JUN-AIR distributor.
d) The pressure switch is defective and does not switch on the compressor.
e) The thermal protection has switched off the compressor due to overheating.
When cooled the compressor will automatically turn on at a suitable operation
temperature. Go through the points in section 4.
f) Pressure in the air receiver is too high for activation of the pressure switch.
The pressure switch makes circuit only when pressure has dropped to preset
start pressure. Empty the receiver.
g) The compressor has not been unloaded and there is back pressure on the
piston. Dismount and check unloader valve (fig. 1). The back pressure may be
due to a leaking non-return valve causing the compressed air in the receiver to
leak back into the compressor motor. Dismount the non-return valve and clean
or change O-ring (fig. 2).
h) Capacitor defective.
2. Compressor operates, but pressure does not increase in tank (or
increases too slowly):
a) The cap on the intake tube has not been removed and replaced by the intake
filter (fig. 3).
b) Intake filter is clogged. Replace.
c) Leaks in fittings, tubes or pneumatic equipment. Check with soapy water or by
letting unit stay overnight with disconnected mains. Pressure drop is not to
exceed 1 bar.
d) Clogged non-return valve or pressure pipe. Clean or replace the parts
(fig. 2).
e) Air leaks from the unloader valve when the compressor is operating. Check or
replace the unloader valve (fig. 1).
f) Defective valve plate. Contact your JUN-AIR distributor.
3. Loud noise from compressor:
a) Most likely broken suspension spring(s). Replace the spring and ensure that
motor position is horizontal.
b) The internal pressure pipe touches the rib cover or the cylinder block.
Dismount the rib cover and bend the pressure pipe away.
4. Compressor gets very hot and/or uses a lot of oil:
a) Incorrect oil level. The level must appear in the oil level glass (fig. 4).
b) Wrong oil has been filled in the compressor. Use only SJ-27 synthetic lubricant
which has the correct viscosity.
c) Leaks. See point 2c.
d) Clogged intake filter. See point 2b.
e) Too high ambient temperature. Do not install the compressor in a cabinet
unless adequately ventilated (fig. 5).
f) The compressor is overloaded (i.e. it is operating more than 50% of the
operation time). Contact your JUN-AIR distributor.
5. Compressor starts when no air is being used:
a) Leaks. See point 2c.
6. Compressor starts and stops more frequently than usual:
a) Condensate in the air receiver. Empty the receiver by means of the drain cock
(fig. 6).
b) Leaks. See point 2c.
Operating manual
(fig. 1)
(fig. 2)
(fig. 3)
(fig. 4)
(fig. 5)
(fig. 6)
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