UL 508A Frequently Asked Questions

Q. It looks like it’s impossible to have an SSC rating higher than 10KA as terminal blocks are all rated 10KA or less. Per NFPA 79, customer connections must be run to terminals up to 80A. How do we increase the rating of a panel with this problem?

A. UL recently made a prevision in the category for terminal blocks (UL Category Control # XCFR2). Manufacturers are testing beyond that 10KA rating. You need to contact manufacturers that have had their terminal blocks tested and approved at higher levels. That is one way to obtain a higher rating.

Category: Application

Keywords: terminal blocks, blocks