3.1 SINAMICS G110D Specifications
Table 3- 3
Max. rated current of the protec-
Siemens 3NA38 series fuses and 3RV series motor starter protectors of a lower current
rating than shown may also be used.
Calculation of the feeder protection according to IEC and UL standards
Calculation of the feeder protection:
● Add together the rated input currents of the inverter group.
● The sum of all rated input currents must be ≤ 24 A.
● Use one of the following protection devices for the inverter group:
– Fuse or circuit breaker with a rated current of 30 A
– Intrinsically safe circuit breaker with a rated current of 25 A
The feeder protection also depends on the following conditions:
● Type of cable routing
● Limit values of the cables and system components, e.g. the T distributor.
● Country-specific regulations
If it is precluded that all of the inverters of a group operate simultaneously, it is permissible to
form larger inverter groups on one 400-V feeder. The sum of the rated input currents of all of
the inverters operated simultaneously must always be less than 24 A.
Branch circuit protection according to UL standards
Use in North America requires protection devices that meet UL standards as detailed in the
following tables. The inverter must be mounted in an UL approved enclosure not less than
the minimum enclosure volume unless the branch circuit protection is a class AJT fuse by
Mersen (Ferraz Shawmut).
Overview of the approved protection devices according to UL standards are given in the
Table 3- 4
Fuses of any manufacturer with faster tripping characteristic than class RK5
and rated 600V AC, e.g. class J, T, CC, G, or CF
Siemens circuit breaker
Siemens Type E combination motor controllers
Branch circuit protection according to IEC
tion device (A)
Approved protection devices for UL standards
Article no. of fuse
Getting Started, 07/2016, FW V3.63, A5E38556288B AA
Article no. of the circuit breaker