(fig. 15). Fit the plug in the power socket (fig. 12 - 13) and start the
compressor, turning the pressure switch knob into position "I". The
compressor is fully automatic, and is controlled by the pressure
switch which stops it when tank pressure reaches maximum value
and restarts it when it falls to minimum value. The pressure difference
between maximum and minimum values is usually about 2 bar (29
psi).
E.g.: the compressor stops when it reaches 8 bar (116 psi – maxi-
mum operating pressure) and restarts automatically when the pres-
sure inside the tank drops to 6 bar (87 psi).
After connecting the compressor to the power line, load it to maxi-
mum pressure and check exactly how the machine is operating.
COMPRESSORS WITH D STARTING CONTROL UNIT (fig. 16)
Fit the plug in the power socket (fig. 13) and turn the pressure switch
to position "I" (ON) (fig. 17). Turn the master power switch "A" on the
control unit to position I – power On is signalled by white indicator-
light "E" going on. Turn switch "B" to position 1 to start the compres-
sor. If the solenoid-valve indicator-light "D" and the motor (C) indica-
tor-light (C) go on in that order, this means the machine is operating
perfectly (fig. 18).
TANDEM COMPRESSORS WITH TIMED CONTROL UNIT (fi g. 17)
Fit the plug in the power socket (fi g. 13) and turn the pressure switch
to position "I" (ON). Turn the master power switch "A" on the control
unit to position I – power On is signalled by white indicator-light "E"
going on.
Turn switch "B" to start the compressor.
Pos. 1 pumping element n. 1 only is operating
Pos. 2 pumping element n. 2 only is operating
Pos. 3 both pumping elements are operating simultaneously, at stag-
gered starting times.
The compressor is fully automatic, and is controlled by the pressure
switch which stops it when tank pressure reaches maximum value
and restarts it when it falls to minimum value.
IMPORTANT
The electro-compressors must be connected to a power socket pro-
tected by a suitable differential switch (thermal-breaker). The motor of
coaxial compressors is equipped with an automatic thermal breaker
located inside the winding – this stops the compressor when motor
temperature reaches excessively high values.
If the breaker is tripped, the compressors restarts automatically af-
ter 10 to 15 minutes. The motors of compressor models coaxial dou-
ble cylinders are supplied with a manually resetting automatic am-
perometric thermal-breaker, located outside the terminal board cover.
When the breaker is tripped, wait for a few minutes and then reset
the breaker manually (fig. 20).
The motors of the belt drive series compressors are supplied with a
manually resetting amperometric thermal-breaker, located on the
terminal board cover. When the breaker is tripped, wait for a few
minutes and then reset the breaker manually (fig. 20).
The safety davice is automatic in three-phase and silent compres-
sors.
When the thermal-breaker is tripped, the pressure switch is released
to "0" (OFF) position.
Wait for a few minutes and return the pressure switch to "I" (ON) posi-
tion. For compressors supplied with a control unit, the thermal-
breaker is installed inside the control unit. When the thermal-breaker
is tripped, observe the following procedure (fig. 22):
• Turn the switches on the control unit cover to position "0", open the
cover and press push-button 1 of the thermal-breaker. Close the cov-
er of the control unit and restart the compressor, observing the opera-
tions described in the paragraph "Starting compressors with control
unit".
The same instructions apply to compressors powered at 60 Hz.
ADJUSTING OPERATING PRESSURE (fig. 23)
You do not have to use the maximum operating pressure at all times.
On the contrary, the pneumatic tool being used often requires less
pressure. On compressors supplied with a pressure reducer, operat-
ing pressure must be correctly adjusted.
Release the pressure reducer knob by pulling it up, adjust pressure to
the required value by turning the knob clockwise to increase pressure
and anti-clockwise to reduce it. When you have obtained optimum
pressure, lock the knob by pressing it downward (fig. 23). For pres-
15
sure reducers equipped without a pressure gauge, the set pressure
can be seen on the graduated scale located on the reducer body.
On pressure reducers equipped with a pressure gauge, pressure can
be seen on the gauge itself.
WARNING: Some pressure regulators do not have "push to lock",
therefore simply turn the knob to adjust the pressure.
Before attempting any maintenance jobs on the compressor, make
sure of the following:
– Master power switch in position "0".
– Pressure switch and the control unit switches all off, in position "0".
– No pressure in the air tank.
Every 50 hours of duty: we advise you to dismantle the suction filter
and clean the filtering element by blowing compressed air on it (fig.
24).
You are recommended to replace the filter element at least once if
the compressor operates in a clean environment, but more frequently
if in a dusty environment.
The compressor generates condensate water which accumulates in
the tank.
The condensate in the tank must be drained at least once a week, by
opening the drain tap (fig. 26) under the tank.
Take care if there is compressed air inside the cylinder, and water
could flow out with considerable force. Recommended pressure: 1 –
2 bar max.
Condensate of compressors that are oil lubricated must not be
drained into the sewer or dispersed in the environment as it contains
oil.
OIL CHANGES – TOPPING UP WITH OIL
The compressor is filled with synthetic oil.
We recommend a full change of oil in the pumping element within the
first 100 hours of duty.
Unscrew the oil drain plug on the housing cover, allow all the oil to
flow out, and re-screw the plug (fig. 27 - 28).
Pour oil into the upper hole of the housing cover (fig. 29 - 30) until it
reaches the level indicated on the stick (fig. 9) or indicator (fig. 11)
Pour oil into the upper hole of the head (fig. 30) in belt assisted units
designed for topping up in that area.
Once a week: check oil level of the pumping element (fig. 11) and
see if it needs topping up.
For operation at ambient temperature in the range -5°C to +40°C, use
synthetic oil. The advantage of this oil is that is does not lose its
characteristics either in winter or summer.
Do not drain used oil into the sewer or dispose of it in the environ-
ment.
OBSERVE THIS TABLE FOR OIL CHANGES
TYPE OF OIL
Synthetic Oil...................................500
Mineral Oil..................................100
WHAT TO DO IF SMALL MALFUNCTIONS OCCUR
Loss of air in valve under pressure switch
This trouble depends on poor tightness of the check valve – take the
following action (fig. 31):
– Discharge all pressure from the tank
- Unscrew the hexagon-head of the valve (A)
- Carefully clean both the rubber disk (B) and its seat.
- Refit all parts accurately.
Air losses
These can be caused by poor tightness of a union – check all unions,
wetting them with soapy water.
Compressor turns but does not load
Coaxial compressors: (fig. 32)
- this may be due to failure of the valves (C1 – C2) or of a seal (B1 –
B2): replace the damaged part.
Pulley drive compressors: (fig. 33)
- this may be due to failure of the valves F1 and F2 or of a seal (D1 –
D2): replace the damaged part.
Compressor no starting
If the compressor has trouble starting, check the following :
- Does mains power match that of the data-plate? (fig. 14)
- Are power cable extensions of adequate diameter or length?
- Is the work environment too cold? (under 0°C)
MAINTENANCE
HOURS OF DUTY
GB