Watson-Marlow MM420 - Manual (Page 207)

Issue 10/06 Short circuit current rating (SCCR)
MICROMASTER 420 Operating Instructions
6SE6400-5AA00-0BP0 207
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 420 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 420, 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.