Industrial Control Panel Fusing

[kingfisher]

I recall seeing something in either the NEC or the UL508/UL508a standards a while back requiring an enclosure to be self-closing/latching if a control circuit transformer primary is fused rather than protected with a circuit breaker. Can anyone point me to an article that makes reference to this? A few google searches haven't yielded any fruitful results.

 

[Dennis Alwon]

The only thing I see is art. 450.8(B)

 

[realolman]

I don't think I've ever seen a self closing / latching enclosure. Look in a Hoffman catalog and see if they even have one.

What would be the correlation between the control fuse and the door latching?

So you could have a bunch of 100 a. 480 volt power fuses and the door could hang open, but if you had a fuse on the control transformer the door would have to latch?