Steam vault disconnect switch

Status
Not open for further replies.
We need to mount a safety switch, on a concrete wall, in an underground steam vault for a sump pump. The vault could be very hot or cold depending on if the steam is on or off. It also could be dry or very moist if there is a steam leak. Stainless steel NEMA 4 makes sense but I could see where it could fill up with condensation. A drain hole also makes sense but that would negate the seal. Also wire temperature. I have planned on 90 degree C THHN but is that high enough temperature? The PVC feed will be run underground to the steam vault and enter into the back of the disconnect. Any thoughts and thanks for your help. Have a good one. Brad
 
We need to mount a safety switch, on a concrete wall, in an underground steam vault for a sump pump. The vault could be very hot or cold depending on if the steam is on or off. It also could be dry or very moist if there is a steam leak. Stainless steel NEMA 4 makes sense but I could see where it could fill up with condensation. A drain hole also makes sense but that would negate the seal. Also wire temperature. I have planned on 90 degree C THHN but is that high enough temperature? The PVC feed will be run underground to the steam vault and enter into the back of the disconnect. Any thoughts and thanks for your help. Have a good one. Brad

I'd be inclined to go with SS just so it does not rust, but provide some means of draining the box.

If you really have high enough ambient temperatures that 90C wire can't handle them, the PVC conduit will fail first.
 
Status
Not open for further replies.
Top