Position In The Dc Link Configuration; Dc Link Fuses; Parallel Configuration Of Central Braking Modules; Braking Resistor - Siemens SINAMICS G130 Engineering Manual

SINAMICS S120 Cabinet Modules
Engineering Information

7.2.10.2 Position in the DC link configuration

The Central Braking Modules must be positioned directly between the largest power units in the DC link
configuration, preferably next to the Line Module. A sequence with several Central Braking Modules located directly
next to one another in order to increase the braking power by parallel operation is not permissible. In this case it has
to be ensured, that larger Motor Modules are installed between the Central Braking Modules.
If continuous braking operation is required, direct installation of Central Braking Modules next to small Line Modules
or Motor Modules with small internal DC link capacitance should be avoided as the resulting DC link currents during
braking operation can overload the DC link capacitors of the small Motor Modules and the braking unit itself. This can
result in significantly reduced lifetime of these units.
Particular care should be taken to ensure that power units located next to the Central Braking Modules are not
permanently disconnected from the DC link configuration by means of a DC interface (option 37). The disconnection
is only allowed for a short time, e.g. for repair or maintainance purposes. If the disconnection is required for a longer
time, the Central Braking Module should be deactivated.

7.2.10.3 DC Link fuses

Every Central Braking Module has a DC link fuse. These are located in the bar between the braking unit and the DC
busbar.

7.2.10.4 Parallel configuration of Central Braking Modules

Central Braking Modules can be operated in parallel on a common DC link in order to satisfy higher braking power
requirements. The braking units operate with a special control circuitry with a soft activation threshold. This means
that no further measures need to be taken in order to operate braking units in parallel with good load distribution.
Therefore the parallel operation of Braking Modules on a common the DC link is possible without additional circuitry
or communication between the units. However, the rules stated in section "Position in the DC link configuration", also
apply to Central Braking Modules operating in parallel. In addition the following has to be taken in account:
-
Every Central Braking Module must be connected to its own braking resistor.
-
Only Central Braking Modules of the same power rating should operate in parallel.
-
The total braking power must be reduced by 10 % due to unsymmetrical load distribution depending
on various system tolerances.
-
The maximum number of Central Braking Modules per DC busbar should be restricted to about 4 in
the interests of power distribution. It is basically possible to connect a larger number on request after
the supplementary conditions applicable to the individual drive system have been assessed.

7.2.10.5 Braking resistor

The regenerative energy of the drive configuration is converted into heat by the braking resistor. The braking resistor
is directly connected to the Braking Module. The braking resistor is installed outside the cabinet unit or outside the
switchgear room. This means that heat losses can be extracted from the area in which the cabinets are installed,
helping to reduce the amount of air-conditioning equipment required in the switchgear room. A temperature switch
protects the braking resistor against overheating. The isolated contact of the switch is responding when the
temperature limit is exceeded. The tripping temperature is 120ºC, which corresponds to a surface temperature of the
resistor of approx. 400ºC.
Braking resistors for the Central Braking Modules must be ordered separately. They have degree of protection IP21.
The following standard resistors with the specified 15-second braking power are available:
Order number of
Central Braking Module
Line supply voltage 380 V – 480 V 3AC / DC link voltage 510 V – 720 V DC
6SL3700-1AE35-0AA3
6SL3700-1AE41-0AA3
Line supply voltage 500 V – 600 V 3AC / DC link voltage 675 V – 900 V DC
6SL3700-1AF35-5AA3
6SL3700-1AF41-1AA3
Line supply voltage 660 V – 690 V 3AC / DC link voltage 890 V – 1035 V DC
6SL3700-1AH36-3AA3
6SL3700-1AH41-2AA3
Matching table for Central Braking Modules and standard braking resistors
SINAMICS Engineering Manual – November 2015
436/528
Ó Siemens AG
Order number of the
matching braking
resistor
6SL3000-1BE35-0AA0
6SL3000-1BE41-0AA0
6SL3000-1BF35-5AA0
6SL3000-1BF41-1AA0
6SL3000-1BH36-3AA0
6SL3000-1BH41-2AA0
Dimensions
Braking power P
BR
W x D x H
(15 s every 20 min)
[ kW ]
500 960 x 620 x 790
1000 960 x 620 x 1430
550 960 x 620 x 1110
1100 960 x 620 x 1430
630 960 x 620 x 1110
1200 960 x 620 x 1430
Braking resistor
R
BR
[ mm ] [ Ω ]
0.95
0.49
1.35
0.69
1.80
0.95