Lenze E82xVxxxKxxxxx - Manual (Page 481)

DC−bus operation
Braking operation in a drive system
Possibilities
12
l
481 EDS82EV903−3.0
12.9 Braking operation in a drive system
12.9.1 Possibilities
If excessive braking energy is generated during operation in generator mode in the DC−bus
system, the voltage in the DC bus increases. If the maximum DC−bus voltage is exceeded,
the controllers will set a pulse inhibit (message "Overvoltage") and the drives will coast
torquelessly. The generated braking energy can be dissipated as follows:
Possible ways to dissipate braking energy
Application area Special features
934x regenerative power
supply module Long braking processes l Braking energy is fed back to the mains
l Low heat generation
Braking unit 8251, 8252
or 9351 Frequent braking with low power
Infrequent braking with medium power l Integrated brake resistor
l No additional switching measures
required
l Example: ( ¶ 480)
Brake chopper 8253 or
9352 Short braking processes with high power l External brake resistor required
l Brake resistor may become very hot,
special protective measures may become
necessary
l Example: ( ¶ 480)
Brake resistor on the
controller Frequent braking with low power
Infrequent braking with medium power
Short braking processes with high power l Only possible with 8200 vector because
it has an integrated brake transistor
l See also: ( ¶ 484)
(
Stop!
The components of the drive system may be destroyed if the following is not
observed:
ƒ Never combine the different possibilities for dissipating braking energy in
the drive system.
ƒ Never use a possibility more than once (e.g. two 935x braking units must
not be operated in parallel).
ƒ The mains voltage on the 93XX controllers and the 935X braking units must
always be set to the assigned value:
– For 93xx via C0173
– For 8200 vector via C0174
– For 935x via switches S1 and S2