# Water in conduit?!



## ErichKeane (Sep 18, 2021)

About 6 months ago, I was installing a plug for my wife's EV charger that sits outdoors.  The charger itself is outdoor rated, and is NEMA14-50.  

SO, I bought this enclosure: https://www.amazon.com/gp/product/B08549S8KK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I mounted it about 8 feet in the air off the side of my shop, and wired out the bottom with the big plastic conduit material.  It comes straight down about 2 feet, and uses a 90 degree conduit elbow to go through the metal wall of my shop, and directly into a junction box, where I used the Polaris connectors tied everything together (6 gauge wire, so wire nuts were out).  I used a TON of silicon sealant on both the inside and outside of the conduit where it entered the building.

Today was our first big rain of the season, and when we went to plug the car in, the light didn't come on! I went into the shop and saw the breaker trip, so flipped it back, just for it to instantly break and release magic smoke from my junction box.

I pulled it apart, and it was pretty fried up, the rubber/plastic on the Polaris connectors (like this: https://www.homedepot.com/p/Polaris...-0B/303578434?source=shoppingads&locale=en-US) were straight charcoal!

It was 'damp' inside the box, so my only theory is that sufficient water got into the box to short something enough to cause catastrophic failure.  I'd like to fix it/redo the work in a way that can survive a storm next time!

I pulled the box apart to check for where water could have gotten in.  The metal wall of the shop is bone dry, and the silicon sealant around the conduit is perfectly in tact and water tight. 

My only guesses are either:
1-condensation: The shop is insulated, but not THAT well?  I sometimes get some condensation on machines, but I can't imagine it would have been THAT much to short a significant distance for those connectors.
2- Water got into the conduit through the top, and just poured in. It is still raining NOW, but I didn't see any obvious water coming in now, though I don't know what could have happened otherwise.  

So my questions are:  Did I do something stupid with the install?  Should I have put some sort of sealant inside the conduit to prevent water from getting in/out?  How do I prevent this from happening again?


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## ErichKeane (Sep 18, 2021)

So right as I clicked 'submit', it started POURING again, so I ran out to check, and I don't see any water coming out the conduit.  Not sure what could have done this.


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## matthewsx (Sep 19, 2021)

Not seeing exactly your setup it's hard to say, but you may need a drip loop to keep water out of the box.

Could be something else entirely though like insects building a nest inside of it too. Need pictures....

John


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## Nutfarmer (Sep 19, 2021)

Did you use aluminum or copper wire . If aluminum wire make sure and use anti corrosion paste on the connections. If not the oxide coating that forms will make resistance at the connection and generate heat.


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## projectnut (Sep 19, 2021)

Does the box have any kind of NEMA rating?  I would think for the situation you're describing you'd need a MENA 3 or better rating.

The box in the link doesn't look that weather tight to me.  Lots of seams and openings to let water in.

Here's a link to some of the NEMA ratings.  We used NEMA 6 boxes in areas that had daily washdowns, and even then over time there were occasions when a seal failed.





__





						NEMA Rating Guide for Electronic Enclosures - Bud Industries
					

NEMA ratings establish a clear guide to waterproof, dust-proof, etc. This quick guide makes it easy to specify enclosures with the right level of protection.




					www.budind.com


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## jwmay (Sep 19, 2021)

This particular problem might be just cause to call in a professional, insured electrician. My .02


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## SLK001 (Sep 19, 2021)

ErichKeane said:


> I used a TON of silicon sealant on both the inside and outside of the conduit where it entered the building.



This type of conduit has its own glue.  Running this is just like running a water line - you glue every joint.  Once completed, the system should be water tight.


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## ErichKeane (Sep 19, 2021)

It was definitely copper wire, AND there was anti-corrision paste inside the big lug connectors.

As far as the box, it claimed to be ok outdoors? Perhaps not...


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## Flyinfool (Sep 19, 2021)

Pictures of the install would be a real help here.

Did you also look inside of the outlet box for water?

Are you SURE that all of the plastic conduit joints are sealed and not just stuck together?

Your enclosure claims to be NEMA 3R rated. You need at least a NEMA 4. NEMA 3 does not have any gaskets, it just has all the open edges pointing down hoping that gravity will keep the water out. NEMA 3 or 3R claims to resist wind driven rain, but a really bad storm can have the same force as water from a hose. Nema 4 is rated to resist the force of a hose. WHile NEMA 6 is better yet, it gives protection against submersion. I think if your box gets submerrged the water in the box will be the least of your worries. On all of the outdoor equipment I design uses NEMA 4, and we have not had any complaints from customers. Even in really harsh places.


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## ErichKeane (Sep 19, 2021)

Flyinfool said:


> Pictures of the install would be a real help here.
> 
> Did you also look inside of the outlet box for water?
> 
> ...


I didn't pull the box down, or get pictures yet.  It was 9 at night in a bunch of rain, so all I did was pull the box apart inside the building that had caught fire (looking for the water ingress).  Once the sun comes out today I'll snap a few pictures of what I have going on.

The plastic conduit joints all had their own seals in them as far as I remember, and I cranked on them pretty tight.  Where it came into the building (around the outside), I used a bunch of silicon caulk to try to keep water out.

I guess I need to stop believing the text online then!  All of them say 'weather proof' or 'waterproof', so perhaps that was a lie  

I've got it under a slight eve, so I thought that would be a bit better for it, but it did rain A LOT yesterday.


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## Flyinfool (Sep 19, 2021)

There is a big difference between weather proof and weather resistant. I will bet that many of the people that write these ads do not even know the difference as well as a lot of people buying the item. 

It is only a lie if you know it to be untrue when you state it. This could just be lack of knowledge.

As for your Polaris connections. since you are using the smallest possible wire in them (They are rated for 3/0-6 AWG.) you have to make extra effort to be sure that the screw is actually getting a good bite on the full dia of the wire. there is room to get the wire a bit off center and not be connecting to all the strands. Missing some strands will make a hot spot. They do make a smaller one that is for 1/0-14 AWG or even better the one that is for 4-14 AWG.


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## ErichKeane (Sep 19, 2021)

Flyinfool said:


> There is a big difference between weather proof and weather resistant. I will bet that many of the people that write these ads do not even know the difference as well as a lot of people buying the item.
> 
> It is only a lie if you know it to be untrue when you state it. This could just be lack of knowledge.
> 
> As for your Polaris connections. since you are using the smallest possible wire in them (They are rated for 3/0-6 AWG.) you have to make extra effort to be sure that the screw is actually getting a good bite on the full dia of the wire. there is room to get the wire a bit off center and not be connecting to all the strands. Missing some strands will make a hot spot. They do make a smaller one that is for 1/0-14 AWG or even better the one that is for 4-14 AWG.


I found the link I bought them from: https://www.ebay.com/itm/163789955077

I think I DID actually get the 4-14 AWG version!  Note it is 3 tap, because I have the junction box splitting off to my shaper.  I know you aren't supposed to split 50 amp service, but its the only way to charge the car and have my shaper in at the same time, AND we only charge the car overnight.


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## ErichKeane (Sep 19, 2021)

Added a couple of pictures. I'm now actually unconvinced there was water in the conduit, that paper towel stayed dry all night in heavy rain. 

I DID use 4-14 polaris connectors, which may have gotten damp due to condensation, but it is weird for it to happen the 1st rain? I would expect there would need to be some sort of time for corrosion to happen.

The problem seems to have been centered on those connectors.


Here is the charger and the plug, conduit goes down to the wall, sealed with silicone.





Other side of the wall. Wire on the right goes to the box, the RPC plug was on the bottom, and the car plug goes through the wall.



Lastly, some of the charred pieces. I think I don't have the actual metal box (just the extension), but that is everything else.


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## matthewsx (Sep 19, 2021)

When you do this again if you DIY, instead of ordering off eBay and Amazon just go to the local professional electrical supply house. I've always found them helpful and occasionally cheaper than the big box store.

Electrical in your home or shop is not the place to try and save money by shopping online, if you DIY make sure you know the needed code and source quality components.

JMHO,

John


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## ErichKeane (Sep 19, 2021)

Not sure how well this captured it, but I see some green crusties on a few wires... I guess this is my culprit.


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## matthewsx (Sep 19, 2021)

Thanks for the picture.

In this situation I think you should be running to the back of the box. And, get the right one....

Yes, corrosion will raise the resistance significantly. But, you should have had overcurrent protection that would trip before stuff actually burned.


John


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## hermetic (Sep 19, 2021)

Condensation inside conduit is common, you need a drain hole at the lowest point, only needs to be 4mm but it is the only way to cure the problem, when a conduit passes from a heated shop to the outside, the warm air from inside the building cools and condensation forms, no amount of sealing will cure condensation, it needs the opposite, ventilation! Better still scrap the conduit and use a wire armoured cable to feed the charger unit!


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## ErichKeane (Sep 19, 2021)

matthewsx said:


> When you do this again if you DIY, instead of ordering off eBay and Amazon just go to the local professional electrical supply house. I've always found them helpful and occasionally cheaper than the big box store.
> 
> Electrical in your home or shop is not the place to try and save money by shopping online, if you DIY make sure you know the needed code and source quality components.
> 
> ...


Sadly, the only electrical supply place around here doesn't serve the public, so I was stuck with what home Depot and Lowes had (plus what I could find online).


matthewsx said:


> Thanks for the picture.
> 
> In this situation I think you should be running to the back of the box. And, get the right one....
> 
> John


Can you clarify what you mean? I'm not sure what you are saying.


hermetic said:


> Condensation inside conduit is common, you need a drain hole at the lowest point, only needs to be 4mm but it is the only way to cure the problem, when a conduit passes from a heated shop to the outside, the warm air from inside the building cools and condensation forms, no amount of sealing will cure condensation, it needs the opposite, ventilation! Better still scrap the conduit and use a wire armoured cable to feed the charger unit!


I can't picture what you mean by that, can you clarify?


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## JimDawson (Sep 19, 2021)

That really looks like damage from loose connections and a heavy load.


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## matthewsx (Sep 19, 2021)

ErichKeane said:


> Sadly, the only electrical supply place around here doesn't serve the public, so I was stuck with what home Depot and Lowes had (plus what I could find online).
> 
> Can you clarify what you mean? I'm not sure what you are saying.
> 
> I can't picture what you mean by that, can you clarify?


Too bad you can't buy directly from the real supply house, it's worth a trip or phone call to someone who knows what you're doing to get this right.

The next box should probably be mounted with wire coming in from behind, if you do use the flexible plastic conduit do as @hermetic says and put a drip loop in with a small hole so condensation can drain out the bottom.

John


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## ErichKeane (Sep 19, 2021)

JimDawson said:


> That really looks like damage from loose connections and a heavy load.


I cranked down on those connectors I thought... Load should have been 40a according to the car charger documentation.  I do think you are right however. My guess of water (since it was a first big rain!) Seems misguided.


matthewsx said:


> Too bad you can't buy directly from the real supply house, it's worth a trip or phone call to someone who knows what you're doing to get this right.
> 
> The next box should probably be mounted with wire coming in from behind, if you do use the flexible plastic conduit do as @hermetic says and put a drip loop in with a small hole so condensation can drain out the bottom.
> 
> John


I think that should be easy enough (the drip loop).


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## ErichKeane (Sep 19, 2021)

matthewsx said:


> Too bad you can't buy directly from the real supply house, it's worth a trip or phone call to someone who knows what you're doing to get this right.
> 
> The next box should probably be mounted with wire coming in from behind, if you do use the flexible plastic conduit do as @hermetic says and put a drip loop in with a small hole so condensation can drain out the bottom.
> 
> John


Even worse, getting an electrician to do the work when I looked into it Was going to take like 6 months. Apparently they are all pretty backlogged, and the permits for a pro install take a long time with the government being so far behind.

The one electrician who was close enough to come check it out (in a small town, was willing to stop by as a favor!) said I was better off doing it myself, otherwise it would probably never get done :/ reality of how stuff is around here unfortunately.


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## woodchucker (Sep 19, 2021)

I agree with Jim, loose connections. Also when you put this together next time, use a no-ox type of coating to prevent oxidation of the connection. And make sure you torque these down, it's important that you don't under, or over torque them.  

I would not have the junction box lower than the outside box, as others have said make a drip loop, move the junction higher or directly behind, not lower.  BTW CLEAR water should not blow the connection... it needs something , some electrolyte to arc over.  I wonder if there was corrosion acting as that electrolyte...


edit: over torquing them is just as bad as loose, you flatten the wire so much and it doesn't have any more elasticity left during heat/contract and loosens on it's own.


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## Bi11Hudson (Sep 19, 2021)

There are several levels of "waterproof". There are "drip proof", rain tight", "splash proof", and on and on. I'm not up on *current* NEMA classes, they have changed several times over the years. To be "waterproof" is many times a marketing gimmick, overlooking the reality of the situation. I am not a "licensed" electrician, having worked in the mills for 50 odd years. I have my own "standards" for any given installation but avoid "explosion proof".

The first issue is the splices. For AWG 10 and larger, I avoid wire nuts completely. They have several weak points and I just don't like them. For anything larger, I use Kearneys, split bolts. They are often a PITA to install, but give a good, solid connection. Crimp on connectors (cigars) I won't even consider. In summary, the splice should be tight enough that it becones one solid piece. Able to support any strain that the wire can withstand. It sounds like you had a loose connection to start with.

Proper insulation will actually survive immersion for a while. I won't go into the many finer points of a power circuit splice, but just a couple of layers of (cheap) vinyl tape won't cut it. It needs to be well insulated.

Conduit entry: No matter what the NEMA rating of an enclosure, if you didn't use a hub to bring in rigid conduit, that rating went out the window. Conduit entries are a weak spot that should be well covered. Never coming in the top, with a few exceptions where fittings meet strict standards. Entering in the lower portion of the sides is optimal. Entering in the bottom means vertical conduit hence a water trap.

Water in the conduit: Starting with condensation between different climatic conditions, water tends to build up in the tightest of conduits. Conduit should never run down, across, and back up. Leaving a "well" to collect water is just asking for buildup. "THHN" insulation class will survive this, other types of insulation will not. And *NEVER* a splice inside the conduit. If the wire is too short, get another wire.

And the *most important issue, to me* anyway. The NFPA, National Electric Code is *not a standard* for electrical installations. It is the *minimum acceptable*. Contractors use the code as a guideline for reasons of pricing. I can't count the installations I have seen that "were to code" and needed to be redone days later. But they met the minimum standards, the inspector said so. . . End of rant

.


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## Suzuki4evr (Sep 19, 2021)

I am just glad that this didn't go wrong in the worst way. I think maybe you should get assistance from an electrician.


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