Water, Jbox and OCPD

[chris kennedy]

I’m looking for a good read. I’m trying to explain why water in a junction box will not cause a thermal magnetic circuit breaker to open.

Thanks

 

[chris kennedy]

I’m looking for a good read. I’m trying to explain why water in a junction box will not cause a thermal magnetic circuit breaker to open.

Thanks

Not GFCI BTW

 

[LarryFine]

I’m looking for a good read. I’m trying to explain why water in a junction box will not cause a thermal magnetic circuit breaker to open.

Look for info on the resistance of water and the distance between wires, and go from there.

 

[Greentagger]

What Larry said. Water provides resistance but not enough to pull XX amount of amps to trip over current protection device. Water may not be a direct short.

 

[kwired]

Because current is pretty low. High enough GFCI and even GFPE will trip, if the water is in metallic box that is bonded/grounded, but low enough even a 1 amp fuse or breaker (no GFCI/GFPE involved) likely doesn't trip.

The more pure the water is the higher it's resistance will be, but most water naturally has some dissolved mineral content and that usually raises conductivity.

 

[augie47]

We had some 50 amp 480 welder receptacles mounted in a cast boxes which filled with water. The 1st indication of a problem was steam coming from the disconnects from the water boiling.

 

[ActionDave]

We had some 50 amp 480 welder receptacles mounted in a cast boxes which filled with water. The 1st indication of a problem was steam coming from the disconnects from the water boiling.

Had the same situation with some 277V sidewalk lights.

 

[kwired]

We had some 50 amp 480 welder receptacles mounted in a cast boxes which filled with water. The 1st indication of a problem was steam coming from the disconnects from the water boiling.

Had the same situation with some 277V sidewalk lights.

But they stopped once enough water boiled away.

 

[GeorgeB]

But they stopped once enough water boiled away.

I always thought electrical and electronic devices needed to keep the smoke in to work ... now you tell me it is steam?

 

[kwired]

I always thought electrical and electronic devices needed to keep the smoke in to work ... now you tell me it is steam?

Actually things can be fine after the steam stops rising, sort of depends on what other contaminants end up in that water.

 

[winnie]

Look up 'electrode vaporizer'. A fairly common household appliance:

Warm Steam Vaporizers

 

[LarryFine]

I used to have an egg cooker that had two plates in the bottom. The salted-water cup was labeled in minutes of cook time.

Another time, I saw a lamp post with the globe and bulb missing, and rain water was steaming out of the exposed socket.

 

[don_resqcapt19]

We had a complete 1000 amp 208Y/120 service panel underwater in the basement of a restaurant and no one even knew it until the heard water running. A water pipe has broken in the basement utility room and the room was filled with water. As an employee was heading down the basement, the solid core fire door broke and all of the water rushed out of the room. No breakers tripped and there was no noticeable power problems. After consulting with the manufacturer we replaced all of the breakers but left the existing panel bus in place.

 

[kwired]

We had a complete 1000 amp 208Y/120 service panel underwater in the basement of a restaurant and no one even knew it until the heard water running. A water pipe has broken in the basement utility room and the room was filled with water. As an employee was heading down the basement, the solid core fire door broke and all of the water rushed out of the room. No breakers tripped and there was no noticeable power problems. After consulting with the manufacturer we replaced all of the breakers but left the existing panel bus in place.

I'd bet inspectors here would still want panel bus replaced. Probably will demand to see the old one to help confirm you did replace it, especially if it were something still in production.