Braking Resistors For Power Units In Chassis Format - Siemens SINAMICS G130 Engineering Manual

SINAMICS S120
Engineering Information
The Braking Modules are delivered without a braking resistor. The resistor must be ordered separately.
The Braking Modules are included in the option range for S120 Cabinet Modules (Options L61, L62 resp. L64, L65).
These options include the corresponding braking resistor as well as installation and cabinet-internal connections of
the Braking Modules.

Braking resistors for power units in chassis format

The surplus energy of the DC link is converted to heat via the braking resistor. The braking resistor is connected to a
Braking Module. By locating the braking resistor outside of the cabinet resp. outside of the converter room, the heat
losses occur away from the Power Units. This reduces air conditioning costs.
Braking resistor for connection to Braking Modules
Resistors suitable for connection to Braking Modules with a rated power of 25 kW resp. 50 kW are available. Larger
outputs can be achieved through the parallel configuration of Braking Modules.
A thermostat monitors the braking resistor for overheating and, if the limit value is exceeded, it issues a warning via
an isolated contact.
Installation
The braking resistors are only suitable for vertical installation and not for installation on a wall. During operation
surface temperatures can exceed 80ºC. In view of this, sufficient distance from flammable objects must be
maintained. A free-standing braking resistor installation with at least 200 mm of free space on each side for
ventilation is required. Objects must not be deposited on or above the braking resistor. The installation should not be
carried out near fire detectors as they could respone by the produced heat. It has also to be ensured that the place of
installation is able to dissipate the energy produced by the braking resistor.
The connection cables to the Braking Module must not exceed 100 m. A short circuit-proof and ground fault-proof
cable routing must also be provided.
SINAMICS Engineering Manual - May 2008
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