SKM Software Issue

by / Monday, 12 August 2013 / Published in Power Systems Study

If you have had a power system or arc flash study done recently using Captor/Dapper software then you may have a potentially serious problem that needs to be addressed. It has come to our attention that SKM does not factor in breaker lug ratings when THHN wire is modeled. THHN wire has a rating of 90 degree Celsius, whereas the circuit breaker lugs have a 75 degree Celsius rating. If the electrical engineer who is performing the study does not recognize this software limitation then the potential exists for circuit breaker lugs to overheat at or near full amp capacity of the wire.

We suggest that all power system studies that have been done using SKM software be reviewed to confirm that THHN wire and breaker lug combination have been modeled correctly. THHN is the most common wire used indoors so it is predictable that almost all studies done with SKM should be checked by an engineer.

The power system engineers at Industrial Tests can verify if your study has been done correctly if desired.