Braking Modules / External Braking Resistors; Braking Modules For Power Units In Chassis Format - Siemens SINAMICS G130 Engineering Manual

6.8 Braking Modules / External braking resistors

6.8.1

Braking Modules for power units in Chassis format

Braking Modules and external braking resistors are required for any system supplied by an Infeed which is not
capable of regenerative operation (Basic Line Module BLM) and in which regenerative energy is occasionally
produced over short periods, for example, when the drive brakes. Braking Modules and external braking resistors can
also be used in systems with Infeeds capable of regenerative operation (Smart Line Module SLM or Active Line
Module ALM) for applications which require the drives to be stopped also after a power failure (for example,
emergency retraction or EMERGENCY OFF according to category 1).
Braking Modules for mounting in air-cooled units in Chassis format are available with continuous braking power
ratings of 25 kW (P power 100 kW) and 50 kW (P
20
and associated control circuitry. The DC link energy generated during operation is converted into heat in an external
braking resistor outside the cabinet. The Braking Module operates completely automously as a function of the DC link
voltage value. It does not interact in any way with the closed-loop control of the associated Line Module or Motor
Module.
Braking Module for mounting in units in chassis format
Multiple Braking Modules can be operated in parallel on a single DC link. The maximum number should be restricted
to between about 4 and 6 Braking Modules per DC link in the interests of equal power distribution. In this case, a
separate braking resistor must be connected to each Braking Module.
For higher braking powers the S120 Cabinet Modules spectrum offers autonomous cabinet components as Central
Braking Modules. These are described in section "Central Braking Modules" of chapter "General Information about
Modular Cabinet Units SINAMICS S120 Cabinet Modules". Braking powers can also be boosted by using a
SINAMICS S120 Motor Module as a 3-phase Braking Module. For more detailed information, please refer to section
"SINAMICS S120 Motor Modules as 3-phase Braking Modules".
Braking Modules for mounting in air-cooled units in Chassis format can be integrated into the power blocks. They are
installed in the discharge air duct of the Line Module or Motor Module and connected to the DC link busbar of the
relevant module. Depending on the frame size of the Line Module or Motor Module, i.e. depending on the number of
power blocks, up to 3 mounting slots are provided.
Frame sizees FB, GB, FX, GX:
§
§ Frame size HX:
§ Frame size JX:
In larger systems with a common DC busbar, it is important to ensure that Line Modules or Motor Modules in which
Braking Modules are installed, are in operation whenever the Braking Modules are required to handle braking energy,
so that the fans of the power units can provide the required cooling air for the modules.
If braking units are used at ambient temperatures of > 40 °C and at installation altitudes of > 2000 m, the derating
factors for current and output power specified for the relevant power units also apply.
The maximum permissible cable length between the Braking Module and braking resistor is 100 m. This allows the
braking resistor to be mounted externally so that the heat losses can be released to the environment outside the
converter room. The braking resistor is connected directly to the terminals of the Braking Module.
power 200 kW). They contain the necessary power electronics
20
1 mounting slot
2 mounting slots
3 mounting slots
SINAMICS Engineering Manual – November 2015
SINAMICS S120
Engineering Information
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