7.3.3
Protecting the braking resistor
Protecting the resistance
The braking resistor must be protected against overheating. A thermostatic switch handles
the protective function (this is supplied with each break resistor). One of the following two
alternatives can be chosen to use this thermostatic switch for protecting the braking resistor:
1. Connect the thermostatic switch to a free digital input of the SINAMICS G120 so that the
Power Module PM240
Hardware Installation Manual, 07/2009, A5E00807525B AD
converter is disconnected from the power supply if the braking resistor overheats.
Subsequently the digital input must be used as release for a switch-off with OFF2.
Figure 7-20
Protecting the braking resistor by a OFF2 command
Accessories
7.3 Braking Resistor
115