spanesi PONYBENCH BEPLUS, Operating And Service Manual

Page: 85 / 242

85
GB
• OPERATION:
When the contacts of the master switch (FR1) are closed,
the current fl ows in both circuits. The transformer (TM),
connected to two phases of the power circuit by means of
the two-pole knife switch fuse-carrier (F3-F4) lowers the
voltage from 400/230 V to 24 V in order to feed the auxiliary
circuit. In this way only the control unit motor power supply
circuit is powered by the line voltage 400/230.
The pump is rotated by the electric motor when the
contacts of the contactor (KP) are closed by the use of the
<ascent> (PS) or <descent> (PD) buttons. The closing of
the <ascent> button contacts also energises the <ascent>
solenoid (EV1) of the hydraulic solenoid valve at the same
time.
The closing of the <descent> button contacts
simultaneously energises the <descent> solenoid (EV2) of
the hydraulic solenoid valve and the solenoid (EV1) of the
pneumatic solenoid valve that releases the safety hook.
The auxiliary control circuit is disabled when the contacts
of the mushrooms-haped emergency (FR1) that stop all
movement are opened by the operator. This disconnects
voltage from both the auxiliary circuit and the motor of
the electrohydraulic unit (MP). In order for normal system
operation to return, the mushroom-shaped emergency
button must be released and the and the magneto-thermal
overload cutout (FR1) must be reset.