Prebena TWINMAX 420 Manual Original página 16

All three-phase compressors are equipped with a 16A / 32A phase-
reversing plug. After connection to the mains, the direction of rotation
must be observed.
HP kW Power supply volt/ph
2 – 3 – 4 1.5 – 2.2 – 3
5.5 – 7.5 – 10 4 – 5.5 – 7.5
NOTE: The equipment must be connected to a maximum impedance
of 0.37 Ω.
NOTE: Compressors installed on the 500 lt tank, with capacity
of HP7.5/5.5 kW and HP10/7.5 kW can be supplied a star/triangle
starting control unit.
Installation instructions:
– Secure the control unit box on a wall or on a fixed support, and
provide it with a power cable with plug, of a diameter in proportion to
its length.
– Any damage caused by incorrect connections of the power line
to the mains, automatically excludes warranty of electrical parts.
To avoid connection errors, we advise you to contact a specialised
technician.
IMPORTANT:
Never use the ground socket instead of the neutral wire. The ground
connection must be made to meet safety standards (EN 60204). The
plug of the power cable must not be used as a switch, but must be
fitted in a power socket controlled by a suitable differential switch
(thermal-breaker).
STARTING
Check that the mains power matches that indicated on the electrical
data-plate (fig.14) the permissible tolerance range is +/-5%. When
first starting compressors operating on 3-phase voltage, check the
rotation direction of the cooling fan by comparing it with the direction
of the arrow on the belt guard or on the protective housing. Turn or
press into position "0" (according to the type of pressure switch fitted
on the appliance) the knob located on the upper section (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 – maximum
operating pressure) and restarts automatically when the pressure
inside the tank drops to 6 bar (87 psi). After connecting the compressor
to the power line, load it to maximum pressure and check exactly how
the machine is operating.
When the temperature is <10 ° C it is recommended to make the
first start with the tank unloaded (0 bar); it is recommended to
depressurize the tank again, in case the compressor has stopped at
low temperature within 30 minutes from the first start up.
COMPRESSORS WITH λD 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 compressor.
If the solenoid-valve indicator-light "D" and the motor indicator-light
"C" go on in that order, this means the machine is operating perfectly
(fig. 18).
COMPRESSORS WITH TIMED
CONTROL UNIT (fig. 17)
Fit the plug in the power socket (fig. 13) and turn the pressure switch
to position "I" (ON). Turn the master power switch "A" on the
Plug model
220/380/3
230/400/3 16A 3 pole + ground
220/380/3
230/400/3 32A 3 pole + ground
control unit to position 1 – 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 staggered 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.
NOTE: The head/cylinder/delivery tube unit can reach high
temperatures. Take care when working near these parts, and do not
touch them to avoid possible burns (fig. 18 - 19).
The electro-compressors must be connected to a power socket
protected by a suitable differential switch (thermal-breaker). If the
breaker is tripped, the compressors restarts automatically after 10
to 15 minutes. The motors of compressor models TWINMAX 420 /
TWINSTAR 470 are supplied with a manually resetting automatic
amperometric 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 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 device is automatic in three-phase and Silent compressors.
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) position. 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 cover of the control unit and restart the compressor,
observing the operations 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,
operating 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 pressure 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.
MAINTENANCE
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
16
IMPORTANT
EN