Safety switches

[mshields]

Safety switches without fuses have fault ratings of less than 10K. Based on this, I have always specified fused disconnects for 480V loads. Am I exceeding what is necessary. Since the switch is not an automatic interrupting device does that make the fault current rating acceptable?

 

[jim dungar]

Safety switches without fuses have fault ratings of less than 10K. Based on this, I have always specified fused disconnects for 480V loads. Am I exceeding what is necessary. Since the switch is not an automatic interrupting device does that make the fault current rating acceptable?

Interrupting ratings are required for all devices which are intended to "break" current regardless if they are manual or automatic.

Non-load break devices must have withstand ratings rather than interrupting ratings.