ECN Forum Forums Code Related Discussion NEC & other Code issues 30 amp RV outlet on GFI??

If an Edison base breaker is installed, the socket is not a fuse holder and therefore not subject to 240.52.
Only, when a fuse is used to replace Edison based circuit breaker, would a type S adapter would need to be installed.

The Edison breaker can be used in "existing" fuse holders but if you are installing a new device it must conform to current code.

I believe the 'S' adaptors intent was to prevent overfusing, back in the day when plug fuses were the means of OCP.

S-fuse adaptors were 'truck stock' along with the S-fuses on service trucks. Heck, we had barrels full of edison base plug fuses, most were 20 & 30 amp.

Now, I have to ask, where could you locate a new plug fuse panel?? Other than the single one pictured.

My house in Maryland (built in 1971) had a SqD fuse panel and that was the last new one I ever saw. I think it had dust on it when they put it in.
It had aluminum wire too.

My neighbor had one with S adapters in it but they put SA-30 adapters in there so it had 30a fuses in every circuit, most 14ga wired.
I put 20s in all of them, not right, but better.
The insurance company finally forced her to replace the panel.