The Contactron has received a short circuit current rating (SCCR) up to 100 kA (according to UL 508). This means it is suitable for use on a circuit capable of delivering not more than 5 kArms symmetrical amperes, 500 V maximum. It is also suitable for use on a circuit capable of delivering up to 100 kArms symmetrical amperes, 500 V maximum when protected by a 30 A class J or CC fuse.