Preparing the motor (motor only), Adjustment of pressure switch (comp.), Adjustment of vacuum switch (vacuum) – Инструкция по эксплуатации JUN-AIR OF300 Series [no cabinet]

Страница 7: Fault finding and repair (all)

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7

Preparing the motor (motor only)

Mounting of vibration dampers OF301 - 50Hz
• Mount the unbraco bolts and nuts in holes on dampers, as

shown (fig. 7).

• Tighten the bolts when the dampers have been correctly

placed, by the protection covers at both ends of the motor
as shown (fig. 8).

• Fasten the motor to the correct mounting, using 4 M6*10

bolts and nuts.

Adjustment of pressure switch (comp.)

Warning!

If maximum pressure is exceeded, reduced lifetime may
result. Contact JUN-AIR for information on operation
at higher pressure.

• All AC and DC motors may run at 100% continuous

operation, but 50% operation is recommendable to prolong
lifetime.

• Do not lubricate the oil-less motor with oil, as this will

destroy important components.

• OF02 may be delivered with one cylinder for vacuum and

one for compression, please contact JUN-AIR for further
information.

• Start the compressor using the 0/1 switch on the pressure

switch (fig. 9). The compressor will automatically switch off
at the preset pressure. If the motor does not start it may
be due to pressure in the receiver, and the motor will then
start automatically when the pressure reduces to approx. 6
bar/87 psi.

• Adjustment of pressure (fig. 10):

A: Max. pressure adjustment (cut-out)

B: Differential adjustment (cut-in)

The cut-in pressure (normally 6 bar) is set by adjustment
of differential screw B. Turn clockwise to reduce cut-in
pressure. The cut-out pressure is set by even adjustment of
the two screws A. (Cut-in pressure + differential = cut-out
pressure). Turn clockwise to increase cut-out pressure.
The switch is normally factory set for operation at 6-8 bar
(approx. 90-120 psi).

Adjustment of vacuum switch (vacuum)

Note!

Vacuum switch is only mounted on units with receiver.

Before adjusting the vacuum switch, adjust the left screw, see (fig.
11) (turn clockwise), so that the indicator on the left scale is all
the way to the top and adjust the right screw, so that the indicator
on the right scale is all the way at the bottom as shown (fig. 12).
This base adjustment results in continuous operation and a
minimum differential pressure of the vacuum switch, e.g. approx.
150 mbar.
Subsequently, the exact adjustment may take place.

Adjustment of maximum vacuum (left screw)
Start vacuum - Differential vacuum = stop vacuum
The procedure below is based on the base adjustment

described above.
1. In practice, the vacuum pump is to operate until the vacuum

required is reached (see vacuum gauge).

2. Switch off the vacuum pump by turning the left screw

counter clockwise.

. Open the air inlet on the receiver in order to ensure

automatic start of the vacuum pump.

4. Close the air inlet in order to ensure automatic stop of the

vacuum pump at vacuum required.

5. Continue the process above (1-4) until the vacuum pump

stops at vacuum required.

Example:
If the vacuum required is e.g. 00 mbar, the vacuum pump will
not start operating until the vacuum is approx. 450* mbar. (The
difference of 150 mbar corresponds to the adjustment on the
differential scale).

* 450 mbar vacuum corresponds to -0.45 on the vacuum gauge.

Fault finding and repair (all)

Important!

Switch off and isolate from electrical supply before
removing any parts from the pump. Empty air receiver
of air before dismantling 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) Defective capacitor.

d) The thermal protection has switched off the pump due

to overheating. When cooled the pump will automatically
turn on at a suitable operation temperature. Go through
the points in section 6.

e) The compressor has not been unloaded and there

is back pressure on the piston. Make sure that the
compressor is unloaded each time it stops.

f) The pump is locked.

g) 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 receiver.

If the vacuum pump is fitted with receiver and vacuum
switch:

h) Vacuum in the receiver. Vacuum pump will switch on

when vacuum reaches the minimum vacuum preset on
the vacuum switch. Open the inlet cock on the receiver.

2. Compressor does not start, makes a buzzing sound

followed by a clicking noise (cannot start against high
pressure):

a) Leaky non-return valve. Remove the flexible pressure

pipe and clean to find out whether air leaks from the
valve. If so, clean or replace.

3. Vacuum pump operates, but does not evacuate

sufficiently:

a) Check the piston gaskets. Replace, if necessary.

b) Defective valve plate. Contact your JUN-AIR distributor.

c) Inlet cock defective. Replace.

If the vacuum pump is fitted with receiver, vacuum filter
or vacuum gauge:

Operating manual

GB

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