Non-fused switches have no SCCR by themselves.
This is odd. It was always my understanding that they had a SCCR of 10k by themselves with higher ratings available under series ratings. I did some digging, and came across some non-nonsensical statements by the manufacturers. These two are from square D, saying similar thing just different wording, I thought I would include them both:
Non-Fusible Heavy Duty Safety Switches do NOT provide any overcurrent protection, therefore the non-fusible heavy duty safety switches alone do NOT provide any SCCR, it MUST be protected upstream by the correct Fuse Class or a circuit breaker.
First, a Non-Fused Safety Switch by itself does NOT provide any short circuit current rating because it does not contain any overcurrent protection.
to me that is non sequitur and I do not follow the logic there. Then this one from Eaton:
The ULT 98 Standard (Enclosed and Deadfront Switches) allows non-fusible switches to have a maximum short-circuit interrupting rating of 10 kA. This is because as a stand-alone device without integral overcurrent protection, the system designer may not know the upstream overcurrent protection. UL permits higher series connected fault current ratings if specific products are tested together. UL Listed combination ratings must be printed on the safety switch pub on the door, and must specify which upstream devices may be used to protect at higher fault current levels. Additionally, UL does not permit series combination ratings with motor circuit protectors
I dont know what to make of the statement in red. A NF switch is interrupting anything. Lets put that aside and assume they mean SCCR and move on to to the blue. Newsflash I guess, if i cant verify the upstream equipment then I cant assume anything, ok got it :roll:, so that statement seems to imply they are rated 10k with no upstream equipment.
So is the common practice of using a NF disco as a meter disconnect switch not allowed, even if the available fault current is under 10k?