Siemens SINAMICS S120 Function Manual page 81

Note
Controlling the brake via a relay for "Safe Brake Control":
If you use the "Safe Brake Control (SBC)" function, the use of relays/contactors can cause
faults in the brake control when brakes are switched. For this reason, this type of control is
not generally permissible.
Undesirable motor motion due to defective brake
"Safe Brake Control" does not detect mechanical defects of the brake.
A cable break or a short-circuit in the brake winding is only detected when the state
changes, i.e. when the brake either opens and/or closes. In SINAMICS S120M, a cable
break is only identified when opening the brake.
For devices in chassis format with connected Safe Brake Adapter, the connecting cable
between the Safe Brake Adapter and the motor brake is not monitored for cable break or
short-circuit.
The aforementioned defects may trigger unwanted motor motion, which may result in
physical injury or death.
• In particular, ensure the brake is not powered from an external source. Information on
• During commissioning, test the brake using the diagnostic function "Safe Brake Test
Functional features of "Safe Brake Control"
● SBC is executed when "Safe Torque Off" (STO) is selected.
● In contrast to conventional brake control, SBC is executed via two channels.
● SBC is executed regardless of the brake control or mode set in p1215. However, SBC
does not make sense for p1215 = 0 or 3.
● The function must be enabled using parameters.
● When the state changes, electrical faults, such as a short-circuit in the brake winding or
wire breakage can be detected.
Enabling the "Safe Brake Control" function
The "Safe Brake Control" function is enabled via parameter p9602.
The SBC function can be used only together with STO. The selection of SBC alone is not
possible.
Safety Integrated
Function Manual, 12/2018, 6SL3097-5AR00-0BP1
WARNING
this topic can be found in EN 61800-5-2, Appendix D.
(SBT)" (Extended Function): Additional information is provided in Chapter "Safe Brake
Test (SBT) (Page 138)".
Description of Safety Integrated functions
4.1 Safety Integrated basic functions
79