NEMA 4X Stainless Steel Junction Boxes Breather/Drain Vents

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I work at a large municipal plant that is at the punch list stage of completion. A lot of our junction boxes have water in them. The contract requires condensate breather valves or drain valves in junction boxes. These have not been installed. Does anyone have any experience with these? Are they more trouble then they are worth? I hate to put another hole in a NEMA 4x box, but we do currently have water issues.

Thanks,
 

kwired

Electron manager
Location
NE Nebraska
I work at a large municipal plant that is at the punch list stage of completion. A lot of our junction boxes have water in them. The contract requires condensate breather valves or drain valves in junction boxes. These have not been installed. Does anyone have any experience with these? Are they more trouble then they are worth? I hate to put another hole in a NEMA 4x box, but we do currently have water issues.

Thanks,
It is either that, drill weep holes (which may or may not be acceptable depending on the application), or eliminate the source of condensation somehow (possibly an enclosure heater will help with that).
 
Weep holes would violate the type 4X rating. There are officially rated breather/drain accessories that carry a UL type 4X rating when properly installed in a rated enclosure.

http://www.hoffmanonline.com/produc..._2=2375&cat_3=69156&catID=69156&itemID=390271

Quit fighting it and comply with your contract. This is SOP, should have been caught up front.



I am the owner, not the contractor. We are deciding whether or not to hold them to the contract on this. It should have been caught up front by our construction manager but they missed it.

I dont have any experience with the breather/drain. Do they work well?

Our main concern is the contractor doing a poor installation and compounding the problem.
 

Jraef

Moderator, OTD
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San Francisco Bay Area, CA, USA
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Electrical Engineer
I am the owner, not the contractor. We are deciding whether or not to hold them to the contract on this. It should have been caught up front by our construction manager but they missed it.

I dont have any experience with the breather/drain. Do they work well?

Our main concern is the contractor doing a poor installation and compounding the problem.
Yes, they work well, they are very simple devices, just a solid plug type of fitting with a tiny baffled channel machined in it for any collected moisture to flow out, but with a gravity valve that stays open unless you try to force water in from the outside (NEMA 4 means hose-down proof).

You just punch a conduit hole and it goes in, just like any N4X fitting, it's pretty hard to screw it up. Then again they have already shown a possible touch of incompetency, so I see your concern. But most likely it's just an oversight or they were unaware of the component, thinking this was some big complicated deal and were unsure of how to deal with it. So pass along that link and make them stick to it, it was part of the job.
 

tom baker

First Chief Moderator
Staff member
Out here in the pacific northwest condensation is an issue. I'll drill a drain hole in all enclosures, we get condensation from the moisture out of conduits.
Drain holes are allowed now by the 2014 NEC.
The breather by Hoffman is a good solution, but also should consider sealing conduits with duct seal or similar.
 

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
Only some designs of drains let all of the water out of the enclosure. Other designs leave an 1/8" of more of water in the bottom of the enclosure.
 

Ken9876

Senior Member
Location
Jersey Shore
Most of the drains I've seen never work as noted above, we just drill weep holes now. For sealing the conduits, polywater seems to have several good solutions
 

kwired

Electron manager
Location
NE Nebraska
Out here in the pacific northwest condensation is an issue. I'll drill a drain hole in all enclosures, we get condensation from the moisture out of conduits.
Drain holes are allowed now by the 2014 NEC.
The breather by Hoffman is a good solution, but also should consider sealing conduits with duct seal or similar.

As Jraef mentioned drilling a weep hole will violate the N4 rating. If N4 rating is not absolutely needed maybe it is still fine to drill the holes though. You kind of have an "improved" 3R rating if it has weep holes, I guess.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
As Jraef mentioned drilling a weep hole will violate the N4 rating. If N4 rating is not absolutely needed maybe it is still fine to drill the holes though. You kind of have an "improved" 3R rating if it has weep holes, I guess.
Yes, might be OK, but ... "Municipal plant" + "Stainless Steel" likely means something corrosive going on there. "Improved" NEMA 3R might be fine, might not. Without knowing, I would not want to second guess that issue and create problems down the road.

Weep Hole Tangent: I once did a large project where I built 142 small pump panels in sealed outdoor boxes (so they were gasketed doors) and drilled weep holes in the bottom. But I wasn't the installer and the guy who got that contract tried to save money because of the mistakes he made that got him the job. So instead of making a concrete anchored strut rack to mount each panel, then run 3/4" conduit in and out as specified, he used a single piece of 3" conduit as both the chase for the conductors AND the mounting support by using a sweep ell through a poured concrete block. Problem #1 was he used my convenient little weep hole as his pilot hole for the 3" Meyers hub. Problem #2 was that he had me remove the alarm beacons from on top of my panels because he was going to find cheaper ones and mount them himself. Turns out they were cheaper because they were INDOOR, not outdoor. Problem #3 was that he had to put in a Chico seal on the 3" conduit because the output wires went to a wet well. So the fixtures leaked, but because the weep holes were gone and the conduit went through a sealed Meyers hub to a Chico seal, the water that leaked into the beacons had no exit and completely filled the conduit, then the enclosures. I got to sell the panels twice...
 

kwired

Electron manager
Location
NE Nebraska
Yes, might be OK, but ... "Municipal plant" + "Stainless Steel" likely means something corrosive going on there. "Improved" NEMA 3R might be fine, might not. Without knowing, I would not want to second guess that issue and create problems down the road.

Weep Hole Tangent: I once did a large project where I built 142 small pump panels in sealed outdoor boxes (so they were gasketed doors) and drilled weep holes in the bottom. But I wasn't the installer and the guy who got that contract tried to save money because of the mistakes he made that got him the job. So instead of making a concrete anchored strut rack to mount each panel, then run 3/4" conduit in and out as specified, he used a single piece of 3" conduit as both the chase for the conductors AND the mounting support by using a sweep ell through a poured concrete block. Problem #1 was he used my convenient little weep hole as his pilot hole for the 3" Meyers hub. Problem #2 was that he had me remove the alarm beacons from on top of my panels because he was going to find cheaper ones and mount them himself. Turns out they were cheaper because they were INDOOR, not outdoor. Problem #3 was that he had to put in a Chico seal on the 3" conduit because the output wires went to a wet well. So the fixtures leaked, but because the weep holes were gone and the conduit went through a sealed Meyers hub to a Chico seal, the water that leaked into the beacons had no exit and completely filled the conduit, then the enclosures. I got to sell the panels twice...

I kind of missed the municipal plant part there, but I have been around fertilizer facilities and they are about the king of corrosive environments as far as I can tell. My experience has been stainless, fiberglass, or PVC enclosures hold up well, but the contents still seem to suffer corrosion.

Smart thing to do is probably try to avoid top entries where condensation is going to be an issue, as well as use enclosure heaters if condensation will be an issue with the enclosure itself. Corrosive environment plus a little water just kind of ends up being worse then just one or the other.
 
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