F Short Circuit Current Rating (Sccr) - Siemens MICROMASTER 430 Operating Instructions Manual

Issue 10/06
F Short circuit current rating (SCCR)
Frame Size C
The equipment has a "standard SCCR" value of 10 kA, which complies with the
requirements of UL508C.
In addition to the "standard SCCR" a "high SCCR" is available which can be used
for industrial control panel installations in line with the National Electrical Code
(NEC) article 409 (edition 2005) and Underwriters Laboratories UL508A (effective
April 2006).
The uL certification of MICROMASTER 430 allows the drives to adopt a high
SCCR equal to the interupt current rating of the branch-circuit protection (BCP)
device protecting the drive.
Hence by selection of the correct uL listed BCP device with appropriate interrupt
rating for the application, any high SCCR rating can be achieved for
MICROMASTER 430, including SCCR values above 10 kA.
The above statements are valid for the respective maximum voltage of the drive
when protected by a UL recognised/listed H, J or K type fuse, a circuit breaker or
self-protected combination motor controller.
Frame Sizes D to GX
The equipment has a "standard SCCR" value of 42 kA, which complies with the
requirements of UL508C.
A "high SCCR", which can be used for industrial control panel installations in line
with the National Electrical Code (NEC) article 409 (edition 2005) and Underwriters
Laboratories UL508A (effective April 2006), can be achieved with the use of current
limiting fuses or circuit breakers with an appropriate interrupt rating and derived let
through current.
For compliance with NEC article 409 and UL508A the calculation, selection and
marking of the current limiting device must be carried out by an qualified engineer.
The above statements are valid for the respective maximum voltage of the drive
when protected by a UL recognised/listed H, J or K type fuse, a circuit breaker or
self-protected combination motor controller.
MICROMASTER 430 Operating Instructions
6SE6400-5AE00-0BP0
http://nicontrols.com
Short circuit current rating (SCCR)
107