Overcurrent Protection By Means Of Line Fuses Or Circuit-Breakers - Siemens SINAMICS S120 Equipment Manual

Cabinet Design and EMC
14.2 Selection of Devices Required for Operating SINAMICS
14.2.3

Overcurrent Protection by Means of Line Fuses or Circuit-Breakers

The cables for the drive line-up power supply must be protected against overcurrent. LV
HBC, D-type, and DO-type fuses with a gL characteristic or suitable circuit-breakers can be
used.
Note
The units can be connected to line supplies up to 480 V
kA symmetrical ("uninfluenced current" acc. to EN 60269-1).
During operation from networks with low short-circuit power (e.g. trial operation, operation
with isolating transformer), the fuses must be designed in such a way that, if a fault occurs,
the line fuses trip after 0.4 s with mobile equipment and after 5 s with stationary equipment
to provide protection against electric shock after indirect contact and in the event of short-
circuits.
Fuses that can operate across the maximum cable length within a circuit must be rated in
accordance with the requirements for:
1. Short circuit protection (IEC 60364-4-43 and -5-52, EN 60204-1, and EN 61800-5-1)
2. The maximum permissible break time for protection against electric shock in the event
3. The maximum permissible voltage drop during operation
The maximum cable length depends on the cable cross-section, material, and insulation, as
well as the type and size of the upstream overcurrent protection device.
The minimum value, which is derived from the three requirements, must generally be
observed. This means that the fuses must be designed in such a way that, if a fault occurs,
the line fuses trip after 0.4 s with mobile equipment and after 5 s with stationary equipment.
306
WARNING
WARNING
of indirect contact (IEC 60364-4-41 and -4–43, IEC 61200-413, EN 61800-5-1, and EN
60204-1)
that can supply a maximum of 36
AC
Booksize cold-plate power units
Manual, (GH4), 03.2007, 6SL3097-2AJ00-0BP4