Rain in the Main

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knoppdude

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Sacramento,ca
Hello everyone, I was busy working at the plant today, thinking everything was ok, even though it was raining heavily. I walked by the office trailer, where a new service panel had been installed, with feeder exiting the top, through the ceiling space, then out to a panel. I installed this, and was told to use a compression fitting threaded into a hub, as this was company policy. kThe conduit is 2 inch emt. Just on a hunch, I opened the panel, and sure enough, water was entering through the fittings. Same with the Main. I siliconed around all threads, which has slowed down, if not stopped the flow. Definitely not a good situation. I told the plant manager about this, and that when I can, I will reroute the feeder under the building, and use a sealing KO on both the main, and the panel. The voltage is 120/240, but this situation still worries me. Has anyone had a similar situation, and what was the long term outcome. It will be raining for at least another week, so I might just start the work on monday, and hope for the best. Thanks
 
Perhaps replace the compression fitting with a rain-tight compression fitting.

Where this isn't feasible, try snow-coat, elastomeric roofing paint.

Larry calls them drain holes, and I agree that providing "weep" holes in outdoor boxes is a good idea. "Drain" sounds like something a plumber would install.:)
 
Nothing is completely waterproof. When I enter the top of breaker panels I try to enter to the side of the breakers and not right above them if possible.

Like the others said, always make sure you have clean and clear drain holes.
 
Thanks for the responses, I am going to do all of the suggestions on monday, then work on rerouting the feeder out of the panel bottom. I have never been as worried as I was friday when I opened these panels. I should have just uses raintight compression connectors with the rubber seals instead of threading into a hub, which is company policy. I think this might have prevented this. That, and not bringing the conduit out of the top of the panel.
 
I might just cut the panel bottom out, and install chicken wire, then coat the entire top with roofing tar. Right after I finished the silicone patch one of the plant mechanics informed me that he had hit a cable powering one of their conveyors. The plant had been operating for a full day with an exposed conducting wire, that was hot while the plant was running. It was one of those days when things kept getting better by the hour. By the time I left, the dozen leaking holes in the top of my POS dodge van didn't seem like much of a bother.
 
K8MHZ said:
So the rain in the main goes mainly down the....weep hole?
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"Drain." :cool:




"Rudolph the Red-nosed Raindeer was killed earlier today while flying over Barcelona, where he was hit by a flock of seagulls, and then a Boeing 757. It appears that the raindeer in Spain was killed mainly by the plane."
 
knoppdude said:
Hello everyone, I was busy working at the plant today, thinking everything was ok, even though it was raining heavily. I walked by the office trailer, where a new service panel had been installed, with feeder exiting the top, through the ceiling space, then out to a panel. I installed this, and was told to use a compression fitting threaded into a hub, as this was company policy. kThe conduit is 2 inch emt. Just on a hunch, I opened the panel, and sure enough, water was entering through the fittings. Same with the Main. I siliconed around all threads, which has slowed down, if not stopped the flow. Definitely not a good situation. I told the plant manager about this, and that when I can, I will reroute the feeder under the building, and use a sealing KO on both the main, and the panel. The voltage is 120/240, but this situation still worries me. Has anyone had a similar situation, and what was the long term outcome. It will be raining for at least another week, so I might just start the work on monday, and hope for the best. Thanks
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I'm willing to bet that not much if any of your leaking was coming from the compression fitting threaded into the hub but was coming from other fitting(s), or a weatherhead with improper drip loop, or even condensation forming within the raceway. I would put condensation at the top of the list of possibilities, it is pretty much unavoidable but can be greatly minimized by sealing interior of raceway so you do not have air flow from warm humid location to a cooler location - that will cause a lot of condensation easily.
 
kwired said:
I'm willing to bet that not much if any of your leaking was coming from the compression fitting threaded into the hub but was coming from other fitting(s), or a weatherhead with improper drip loop, or even condensation forming within the raceway. I would put condensation at the top of the list of possibilities, it is pretty much unavoidable but can be greatly minimized by sealing interior of raceway so you do not have air flow from warm humid location to a cooler location - that will cause a lot of condensation easily.
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There is no drip loop, but I agree with you that condensation is a possible problem. So, after reading the posts, when the rain slows down, I am going to replace the hubs with raintight connectors, seal them on the outside with every type of sealant listed, and seal the raceway interior. Also, add about a dozen holes in the bottom. I think this debacle might have more long term effect than immediate consequences, so tomorrow I will find out if everything is good, and then make a trip to a few supply stores. Thanks for the input from all of you.
 
The raintight connectors with rubber washers are a joke. The washer is gone or slipped out of place within a year or two. Absolute POS. The compression gland inside the fitting is good. Seal each end for condensation. Silicone or paint as needed and arrange to drain the future projects
 
knoppdude said:
There is no drip loop, but I agree with you that condensation is a possible problem. So, after reading the posts, when the rain slows down, I am going to replace the hubs with raintight connectors, seal them on the outside with every type of sealant listed, and seal the raceway interior. Also, add about a dozen holes in the bottom. I think this debacle might have more long term effect than immediate consequences, so tomorrow I will find out if everything is good, and then make a trip to a few supply stores. Thanks for the input from all of you.
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Before you go through all of that run a water hose on the hub in question and see if it is leaking, as long as everything is tight and the gasket is in place it likely is not leaking or is leaking very little. Sealing for condensation is more likely a bigger issue and still will be after changing everything.
 
Well, monday, the main was dry, but one of the panels it fed was still slightly wet. I added more silicone, where it looked questionable. I did order the water tight connectors, and agree that the rubber gasket looks weak. I told the manager that I will fix it when things dry out, and do so on my time, I told him that as I worked on it, I own it, and am responsible. The situation involved several chiefs, and one grunt (myself), and I knew the install might have this problem. Now the rain in the main is no longer my bain, and when it is solved, it won't be involved. Nuff said. Thanks for all of the responses to this, bottom line is that a different design would have avoided this altogether.
 
knoppdude said:
Now the rain in the main is no longer my bain, and when it is solved, it won't be involved.
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How poetic. :) (By the way, it's "bane")

I've seen rain travel inside conduits and even SE sheaths. Don't overlook the upper ends of cables or couplings.
 
knoppdude said:
Well, monday, the main was dry, but one of the panels it fed was still slightly wet. I added more silicone, where it looked questionable. I did order the water tight connectors, and agree that the rubber gasket looks weak. I told the manager that I will fix it when things dry out, and do so on my time, I told him that as I worked on it, I own it, and am responsible. The situation involved several chiefs, and one grunt (myself), and I knew the install might have this problem. Now the rain in the main is no longer my bain, and when it is solved, it won't be involved. Nuff said. Thanks for all of the responses to this, bottom line is that a different design would have avoided this altogether.
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I don't know enough details about your install but have seen many 3R enclosures with improper entries, loose fittings, even set screw fittings. Do they leak? - yes. They don't always leak too severely, it depends on conditions at the location of the installation. I'm just telling you to make sure that before you go through the trouble to replace the fittings you may want to dump some water on the area in question and see how much leakage you get. Otherwise you may find that the main problem was somplace else.

Are there any fittings in the raceway that are either sitting in a place where water may puddle or is diverted somehow to where a fitting may be? Check out all fittings in the run your leak could be in any one of them, or as I previously mentioned it could just be condensation.
 
LarryFine said:
How poetic. :) (By the way, it's "bane")

I've seen rain travel inside conduits and even SE sheaths. Don't overlook the upper ends of cables or couplings.
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Sorry about the spelling, but I just couldn't resist. KWired, when things dry out, I will do exactly what you have suggested. The system has been rained on before without problems, but this storm had more force, especially wind. One of the first things I did was take pliers to all of the fittings, then used silicone. I think that the water came in from a number of locations, so once things dry out I will fix it. Of course, the test for that will be the next storm.
 
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