Lenze EVS9332xS - Manual (Page 87)

Function library
Function blocks
3.2.13 Holding brake (BRK)
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l
EDSVS9332S−EXT EN 2.0
3.2.13 Holding brake (BRK)
Danger!
Condition for using the BRK function block
Triggering the holding brake solely via the function block BRK is not permissible!
The safe triggering of the holding brake additionally requires a second switch−off path. Unsafe
triggering creates the risk of severe personal injury and danger to material assets!
Applications with active loads
When the DC−bus voltage increases (e.g. by braking processes), the torque limitation may be
activated via code C0172. The torque limitation becomes active if for instance the brake resistor is
defective or the switching threshold set on the brake chopper or the brake module is not correctly
adjusted.
Code C0172 is a pre−stage of the monitoring function OU" (overvoltage of the DC−bus voltage).
Code C0172 defines the voltage difference to OU causing a reduction in torque. In the Lenze setting,
the torque is reduced to "0" if the DC−bus voltage reaches 760 V (770 V − 10 V):
l OU threshold = 770V (C0173 = 0...3)
– Exception: OU threshold 800 V for C0173 = 4 (see description in code table)
l C0172 = 10 V
l No message is generated.
Only after the DC−bus voltage has decreased below the OU reconnection threshold, the torque is
reconnected.
With unchanged basic conditions the continuously "chopping" drive behaviour may lead to
undefined motions.
Remedy
1. Set C0172 = 0 V
2. MONIT−OU has to generate EEr−TRIP (e.g. by C0871/0 = 15011).
– By this, the standstill brake is engaged via controller inhibit (CINH) if the braking energy
cannot be dissipated.