Bosch 4306 Service Manual download pdf (Page 28)

• DOK-POWER*-KDV*2.3****-ANW1-EN-E1,44 • 06.97

4. Control circuits

Circuit design

4.3. DC bus short-circuiting switch

The DC bus short-circuit switch recommended by INDRAMAT is conceived to

protect either machine or plant against damage in the event of a drive failure.

This can be used to brake motors with permanent magnetic excitation even

in the event of drive control failure. This function cannot, however, be the only

safety device used to protect personnel.

This DC bus short-circuit contactor can switch the "short-circuit current" on but

not off. The DC bus short-circuit contactor may not be re-applied, once

released, until the DC bus has discharged. The following recommended

circuits (section 4.4) will make interference-free operations possible.

Programming the PLC appropriately does not guarantee the correct switching

sequence. The varying contactor actuating times can possibly trigger the

mains contactor before the DC bus short-circuit contactor is opened. This

means that the mains contactor should additionally be locked by means of an

auxiliary contact of the DC bus short-circuit contactor.

The DC bus short-circuit resistor is not secured against accidental

contact. There is the danger of high-voltages (greater than 50 V).

Electrical shock resulting from contact

==>

use an appropriate cover, see that it is in place or properly mounted

Thermal damage caused by DC bus short-circuit contactor and

resistor in the event of faults in the control or contactor is possible.

Damage or loss due to fire is possible inside the control cabinet.

==> use an appropriate cover, see that it is in place or properly mounted

DANGER

CAUTION

Fig. 4.3: Suitable covers and unit arrangements for the DC bus short-circuit

275

130

150

DC bus

short-circuit

resistance

170

Minimum distance

to the front

DC bus

short-

circuit

contactor

cable

routing

from below

AbdKDV23

Cover

min. 50

1 2 ... 23 24 25 26 27 28 29 30 31 32 33 ... 56 57

Comments to this Manuals

No comments

Bosch 4306 Service Manual Page 28

Comments to this Manuals

Related products and manuals for Dishwashers Bosch 4306