DC link components   
8.3 Braking resistors 
  SINAMICS S120 Combi 
162  Manual, Edition 07/2012, 6SL3097-4AV00-0BP3 
8.3  Braking resistors 
8.3.1  Description 
A braking resistor is used to dissipate the excess DC link energy in generator operation. One 
braking resistor is connected to one Braking Module. 
Resistors without thermostatic switch are available with various rated powers. 
Mounting 
The braking resistors can be mounted standing on the floor of the control cabinet or 
suspended. You must ensure that the braking resistors do not obstruct the flow of cooling air 
to the drive line-up. 
Positioning the braking resistor outside the control cabinet or switchgear room enables the 
resulting thermal losses to be routed away. This reduces the level of air conditioning 
required. 
Connection cables 
A shielded connection cable (3 m, 3 x 1.5 mm
2
) is supplied with braking resistor 6SN1113-
1AA00-0DA0. 
Other braking resistors are supplied without connecting cable. The maximum conductor 
cross-sections are listed in the technical data. 
The maximum cable length for all braking resistors is 10 m. 
8.3.2  Safety information 
 
DANGER 
 
The cables to the braking resistor must be installed in such a way that they are inherently 
short-circuit and ground-fault-proof. 
 
CAUTION 
 
The braking resistor can become very hot. Consequently, it must be installed so that it 
cannot be touched or, if this is not possible, an appropriate warning notice must be 
attached to it. 
 
CAUTION 
 
The cooling clearances of 100 mm above and below the components must be observed.