In the last month I have encountered two similar electrical problems. The first was a large plastic water tank that overflowed and quite a lot of water ran down through the conduit that connects the tank’s pump to its control unit, soaking the control equipment. And today I worked on a house which had a faulty masthead that allowed rain to run through the conduit to the panel in the crawlspace, corroding the main breaker.
Shouldn’t there be drain holes on the conduit’s horizontal runs to prevent this?
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I am just currious as to why the panel with the main breaker is in the crawl space. I am not an elecrtrician but that does not sound right.
It is a sloped crawlspace that goes from 4 ft to 7 ft. You could call it a poor man's basement. As long as there is a door for access and sufficient head height, our code allows it.
Thanks for satisfying my curiosoty.Wallyo
Sounds like poor installation.
Our AHJD would have a fit if they saw a drain hole in a run of conduit. If it is a wet location the assembly is required to have rain tight or weather tight fittings.
That said, even using the right stuff won't be enough if the design is flawed to start with.
during my final the electrical inspector told me to drill a small drain hole at the bottom of the service entrance where the conduit turns to pass through the foundation, reason being he said was that the joints weren't always tight water can enter from above and warm air from the house will condense inside the pipe .. even though entrance to panel is plugged with electrical putty ..
Edited 1/15/2008 8:20 am ET by wane
Yeah, drain holes would make sense. Whether they're code or not is another issue.
not rain.
more likely condensation or moisture wicking through the wire...
rain would cause more damage than just at the main breaker..the same problem occurs with pipes underground .. frost will form inside the panels
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, wer ist jetzt der Idiot ?
I should have given a better description. The rain entered the masthead on a pole, went down and corroded the meter, and then filled the conduit that travelled underground to the panel in the nearby building's crawlspace. The pipe was full enough to force the water up into the panel from where the conduit entered from below. All the breakers look like hell, but the main was the first to fail.
In that case, you can certainly drill drain holes in the meter can and the panel.. use duct seal on both ends of the conduit and relocate the panel to some higher elevationit sounds like the existing was below the high water mark.
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The rain entered the masthead on a pole, went down and corroded the meter, and then filled the conduit that travelled underground to the panel in the nearby building's crawlspace
Something doesn't sound right about that installation. I am not familar with the term masthead.
Do you mean a weatherhead on a conduit that runs from the meter base up the pole?
A properly installed weatherhead will not allow water to enter, provide there is a drip loop in the cable.
Maybe solving the problem of that much water getting in the conduit is the place to start, rather than just drining the pipe all the time.
Dave
i would be inclined to think just water in the pipe caused the corrosion and not water flowing through itit not that unusual to find badly corroded stuff where there are temp differentials.
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One thing you can have is air exiting the house through the conduit and moisture in it condensing when it hits the cold mast. One of many reasons why you should use duct seal.
If your view never changes you're following the wrong leader
I have heard of that !.
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That was my first though too, but he keeps saying it is water entering at the "masthead". He also says it passed through the meter base and is then forced up through the conduit into the service panel.
I'm now thinking that it may be a piece of broken conduit or an open joint in the underground pie between the meter and the panel.