Siemens SINAMICS G120 Operating Instructions Manual page 333

Caution
The connection between the brake on the motor and the Safe Brake Control Relay is
supervised at forced dynamisation but not during operation.
Prerequisite: P1215 = 1 and the optional Safe Brake Control Relay
To activate the Safe Brake Control function, the following parameters must be set: P9602 =
P9802 = 1 (factory setting is 0).
In case of P9602 = P9802 = 1 a test signal regarding the signal to the Safe Brake Control is
created. This tests the signal not the brake itself.
This test signal does not interfere with the normal function of the mechanical brake. If the
mechanical brake is fitted and the test fails, a fault condition will be indicated by the inverter.
Note
When carrying-out the forced dynamisation, the shutdown paths of the motor brake are also
tested. This results a brief opening command (2 ms to 28 ms) in the motor brake.
The mechanical part of the brake generally requires longer than 30 ms to open. This means
that this dynamic operation generally has no influence on the motor shaft itself. However it is
the user's responsibility to use brakes with opening times > 30 ms.
The SBC will be activated in the following cases:
● STO/LSTO
● SS1
The SBC state is indicated in P9772.14. If SBC is disabled by P9602 = P9802 = 0 then
P9772.14 is set to 0 (brake open) even if the brake is closed from a non-safe brake control
(e.g. MHB).
Control Units CU240S
Operating Instructions, 11/2006, A5E00766042B AA
Functions
8.18 Fail-safe functions
8-137