Instruction Manual PMC-2
BA * PMC-2 * EN * 01/98 Page 35
4.4.4 DC-circuit
The rectification of the power supply and the storage of the electrical energy in the PMC-2 takes place
in the so-called direct current circuit. The DC-circuit essentially consists of a rectification and
capacitors. With the PMC-2 the DC-circuit voltage is laid on the power plug X1.
CAUTION
DC-Voltage can be up to 725V!
Isolation of the flexes has to be sufficient!
Do not earth the DC-circuit!
DC-circuit stress limit
In brake operation the servo motor functions as generator and feeds back energy into the DC-circuit
via motor dc.-ac. converter. The energy is stored in the DC-circuit capacitors, in this connection the
voltage of the dc-circuit increases. If the capacitance of the capacitors is not sufficient to consume the
energy incurring, it has to be secured that the DC-circuit voltage does not become too high.
The voltage monitoring registers the DC-circuit voltage and - in case of exceeding a certain limit
value - switches the DC-circuit via power transistor to a bleeder, in which the brake energy is
transformed into heat. If the DC-circuit voltage drops below the switching threshold (approximately
700 V) the power resistor will be switched-off again.
CAUTION
When utilising the max. braking power the air outlet temperature of the bleeder
module can be > 100°C.
Connection of the external bleeder:
To Next Page
Loading...