Jun-Air 2xOF302-40B, Operating Manual

Page: 8 / 54

8
Preventive maintenance (all)
Weekly Monthly Annually
Drain condensate from air receiver.
If equipped with autodrain, this will
take place automatically, however,
drain bottle has to be emptied.
If compressor is fitted with outlet
filter, check and empty for water
by pressing the black button at the
bottom. If fitted with autodrain, this
will take place automatically.
Check motor, air tubes, hoses and
equipment for leaks, and check the
pumping time.
Clean unit or wipe with a soft, damp
cloth. If necessary, use paraffin on
rag to remove sticky adhesions.
Dust and dirt prevent cooling.
Check intake filter. Clean or replace
if necessary. Min. annually or every
2000 hours whichever comes first.
Replace silencer (intake filter), if
necessary (fig 1 - Loosen air filter
using e.g. a large coin (1)) + (14
- Replace and tighten new air filter
using a coin (2)).
Check the O-ring in the non-return
valve and replace, if necessary.
Note! Empty receiver of air before
dismounting.
Check filter and filter elements for
optimum efficiency.
Test the safety valve by gently
pulling the ring with pressure in the
receiver.
d) Vacuum filter is clogged. Clean or replace filter element.
e) Leaks in fittings, hoses or equipment. May be located by
closing inlet cock. Dead-end vacuum is to correspond to
the charts on page 41.
f) Vacuum gauge defective. Replace.
4. Compressor works, but pressure does not increase:
a) Intake filter clogged. Replace.
b) 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.
c) Check the piston gaskets. Replace, if necessary.
d) Defective valve plate. Contact your JUN-AIR distributor.
e) Failure in non-return valve which is creating a flow
restriction.
f) Leaks in fittings, tubes or pneumatic equipment. Check
unit by letting unit stay overnight with disconnected
mains. Vacuum switch is not to drop to 0 bar.
5. Loud noise from compressor:
a) Dirt or failure in non-return valve. Clean or replace.
6. Motor gets very hot:
a) Leaks. See point 4b.
b) Clogged vacuum filter. See point 4a.
c) Too high ambient temperature. Ensure adequate
ventilation if the vacuum pump is installed in a cabinet.
d) Overloaded. Ensure compressor is correct model for
work load.
7. Compressor starts when no air is being tapped:
a) Leaks. See point 4b.
8. Vacuum pump starts when no vacuum is being used:
a) Leaks. See point 4f.
9. Vacuum pump starts and stops more frequently than
usual:
a) Leaks. See point 4f.
10. Vacuum pump does not start at minimum vacuum or
does not stop at stop vacuum:
The following points only apply to units with vacuum gauge:
a) Vacuum switch defective. Replace.
b) Vacuum switch is not adjusted correctly. Adjust correctly.
11. Compressor does not switch on against pressure or
does not switch off at max. pressure:
a) Defective pressure switch. Replace.
Test the non-return valve
·
Once a year.
·
Switch off compressor on the main switch and pull out the plug.
·
Pull the ring at the end of the safety valve (fig. 17).
Warning:
Loud noise!
·
Let pressure fall to 0 bar. The pressure is to be read on the
pressure gauge for receiver pressure (fig. 12).
·
If the compressor is mounted with a TÜV-approved safety
valve, the receiver is emptied by loosening the screw at the
end of the safety valve (fig. 19).
·
Dismount non-return valve from receiver (fig. 25).
·
Disassemble non-return valve and remove O-ring from
piston (fig. 26 and 27).
·
Clean non-return valve.
·
Mount new O-rings and re-assemble non-return valve (fig.
28). (Two O-rings in non-return valve)
Replace coal brushes on DC motors 2000 hours
Please note: Vacuum pumps without air receiver are not supplied with vacuum filter.
Check the pumping time (Comp.)
The pumping time indicates the condition of the compressor
provided that there are no leaks in the system where the
compressed air may leak. Test the compressor as follows:
1. Empty the air receiver of compressed air (the pressure
gauge shows 0 bar).
2. Close the outlet on the air receiver and check that the drain
cock is closed.
. Start the compressor and note how long it takes until it
switches off.
Ensure that the pressure in the air receiver is 8 bar/120 psi
as deviations may indicate the wrong results (see Technical
Specifications for pumping time).
Important!
Always test the compressor when cold as the time
indicated refers to the pumping time of a cold
compressor. The pumping time of a warm compressor
is much longer and consequently, the result would be
misleading.
Operating manual
GB