Jun-Air 1000 motor, Operating Manual

5

Preventive compressor maintenance

An hour meter is installed on all "BD" and "PD" models. 
Observe after 1 month how many hours the compressor has 
performed in order to obtain an impression of the maintenance 
intervals ­ which are every 2000 working hours. However, at 
least once every year.

Weekly

Monthly Annually

If compressor is not fitted with dryer, 
drain condensate from air receiver 
(at a pressure of max. 2 bar/0 psi). 
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 in the 
bottom. If fitted with autodrain, this 
will take place automatically.

Make sure that the fan at the top 
of the cover works. Fan starts at a 
motor temperature of 2°C/89°F and 
runs continuously until temperature 
has fallen, although compressor 
does not work. 

Check compressor, air tubes and 
equipment for leaks, and check the 
pumping time.

Inspect and replace intake filter, if 
necessary.

Clean the compressor with a soft, 
damp cloth. Dust and dirt prevent 
cooling.

Check dryer function according to 
instructions in the "Adsorption Dryer 
Manual".

Check the O­ring in the non­return 
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.

Replace the air intake filters after each 2000 working hours
1.  Switch off current.
2.  Lift off the upper part of the cabinet (is locked with screws). 

Be careful not to unplug the cable for the fan (this only 
applies to model „P“) (fig. 5).

.  Pull out the filters by means of inserting a screwdriver below 

the rubber part. The new filters can then be pressed into 
place (fig. 6).

Compressors with adsorption dryer:
1.  Test that the automatic dryer/filter works satisfactorily 

by opening the manual control drain cock, which has an 
internal tube leading to the bottom of the air receiver. If 
water comes out, the dryer needs to be serviced. (See 
"Adsorption Dryer Manual").

2.  In order to avoid pressure loss due to saturated filter 

element, the pre and after filters are equipped with a pop­
up indicator. When the filter element needs replacement, 
the indicator turns red instead of green. Under normal 
conditions the filter element must be replaced after 
approx. 4000 working hours. If the environment is very 
contaminated, intervals for changing filter element may be 
2000 working hours. See "Adsorption Dryer Manual" for 
further information.

.  After 2000 to 4000 working hours dependent on the working 

conditions or when desiccant in inspection glass changes 
color, the desiccant in the dryer system must be replaced, 
see "Adsorption Dryer Manual".

Check the pumping time
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. 
Make sure that the pressure in the air receiver is 8 bar/
120 psi as deviations may indicate the wrong results (see 
technical details).

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.

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 (no sound):
 

a)  No power from mains. Check fuses and plug.

b)  Breakage or loose joints in electrical connections.

c)  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. 

d)  Capacitor defective.

2.  Compressor does not start, makes a buzzing sound 

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

a)  Leaky non­return valve. Remove the flexible pressure 

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

3.  Compressor works, but pressure does not increase in 

tank (or increases too slowly):

a)  Intake filter clogged. Replace.

b)  Leaks in fittings, tubes or pneumatic equipment. Check 

with soapy water. Pressure drop is not to exceed 1 bar 
per hour.

Operating manual

GB