Siemens SINAMICS G150, Operating Instructions Manual

Page: 133 / 680

Electrical installation
4.10 Other connections
Converter cabinet units
Operating Instructions, 07/2016, A5E03347396A
133
4.10.11 Braking unit 50 kW (option L62)
Description
Braking units are used when regenerative energy occurs occasionally and briefly, for
example when the brake is applied to the drive (EMERGENCY STOP). The braking units
comprise a chopper power unit and a load resistor, which must be attached externally. To
monitor the braking resistor, it has an integrated thermostatic switch, which is included in the
shutdown circuit of the cabinet unit.
Table 4- 34 Load data for the braking unit
Line voltage Continuous
chopper power
P
DB
Peak chopper
output
P
15
Chopper
P
20
output
P
20
Chopper
P
40
output
P
40
Braking resistor
R
B
Max. current
660 V ... 690 V 50 kW 250 kW 200 kW 100 kW 4.9 Ω ± 7.5% 255 A
Installing the braking resistor
The braking resistor should not be installed in the vicinity of the converter. The installation
location must fulfill the following conditions:
● The braking resistors are only suitable for floor mounting.
● The maximum cable length between the cabinet unit and braking resistor is 100 m.
● Sufficient space must be available for dissipating the energy converted by the braking
resistor.
● A sufficient distance from flammable objects must be maintained.
● The braking resistor must be installed as a free-standing unit.
● Objects must not be placed on or anywhere above the braking resistor.
● The braking resistor should not be installed underneath fire detection systems, since
these could be triggered by the resulting heat.
● For outdoor installation, a hood must be provided to protect the braking resistor from
precipitation (in accordance with degree of protection IP20).
WARNING
Danger to life due to fire when incorrectly installed
If incorrectly installed (non-observance of the cooling clearances or inadequate clearances
to flammable objects), there is the danger of fire damage with death or severe injury.
•
It is essential that you maintain a cooling clearance of 200 mm on all sides of the
braking resistor with ventilation grills.
• Maintain sufficient clearance to objects that can burn.