Short circuit current rating (SCCR)  Issue 10/06 
  MICROMASTER 440      Operating Instructions 
300  6SE6400-5AW00-0BP0 
F  Short circuit current rating (SCCR) 
Frame Sizes A to 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 440 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 440, 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