I forgot to include it in the schematic, but the primary side is fused with a 5A fuse. the true system is powered by AC mains that feed the variac and a logic supply, the fuse was placed before a power switch that connects the whole system and was chosen with the power supply, Variac, and transformers in mind. The fuse on the secondary side is rated for 1000Vac. Thank you for the document link as well.

I was mainly wondering if i could use the output of a comparator op-amp to drive an LED in series with a resistor? Or, is it necessary to use a transistor configured as a switch? The question came about because I was not sure how to tell if a given op-amp would be able to source the current necessary to drive the LED