# Entering the top of NEMA 4X with Myers Hub



## Southeast Power (Jan 18, 2009)

We are installing several NEMA 4X stainless combo starters outdoors.
I usually try to enter the enclosure near the bottom side below any of the interior components.
It would be very simple to enter the top using a Myers hub. The lower side would require LBs and LRs. We have both on the job.
Question:
Are NEMA 4X enclosures typically entered in the top, or is that a possible problem. All of the conduit work is GRC.


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## MotoGP1199 (Aug 11, 2014)

I've done it before without issue. I try not to if at all possible. When I have done it I used Kopr-Shield on the threads and really tightened the myers hub up real good. If not I try to enter the bottom or the side near the bottom. If entering on the side I just use a LR/LL with a short nipple and myers hub. The threads on both of those (conduit body and hub) are tapered and will not leak.


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## micromind (Aug 11, 2007)

I've done tons of them from the top but on the other hand, we get about 5" of rain a year. 

I've also used sealing locknuts on top and normal ones inside, never had a problem.


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## gpop (May 14, 2018)

Pay a little extra time and effort on the holes you drill or punch removing burr's. Also make sure the seal on the hub doesn't fall off while being installed and crank them down tight then you shouldn't have a problem. 

Most of the problems i have seen over the years due to water entering a top punched box comes from the conduit allowing water intrusion rather than the hub.


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## macmikeman (Jan 23, 2007)

map costs extra


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## Cow (Jan 16, 2008)

I think most folks would just enter the top centering the conduit or enter right above the breaker to make terminating easier.

If possible, I always try to enter off to the side at the top. So when the myers hub leaks, I have a chance that it'll drip to the side of the starter/breaker, rather than right on top of it. 

We would also drill a drain hole in the bottom.


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## MechanicalDVR (Dec 29, 2007)

I've done them with a Myers hub on top when told that was how they wanted them but you know it will leak.

Bottom entry is always best.


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## splatz (May 23, 2015)

I would try a myers hub with 3M mastic along the edges. I had a couple rooftop penetrations where the vertical "raintight" emt fittings, were not. I was getting a little drip in. 



I sealed around where the fitting meets the pipe on the vertical fittings with 3M mastic and it's been dry as a bone. Look for the one that's moldable and UV stable. I have been very impressed with how this stuff holds up.


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## gpop (May 14, 2018)

Cow said:


> I think most folks would just enter the top centering the conduit or enter right above the breaker to make terminating easier.
> 
> If possible, I always try to enter off to the side at the top. So when the myers hub leaks, I have a chance that it'll drip to the side of the starter/breaker, rather than right on top of it.
> 
> We would also drill a drain hole in the bottom.


Old guy taught me if you can not make it waterproof make it leak.


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## joe-nwt (Mar 28, 2019)

I find the myers hubs tend to hold up better if you tighten the lock ring portion rather than using the hub itself. Twisting the hub part mangles the o-ring and that's where a lot of the leaks start.


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## Wirenuting (Sep 12, 2010)

When I've had no other choice, I'll tilt the enclosure slightly to allow water to drain off.


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## Southeast Power (Jan 18, 2009)

Wirenuting said:


> When I've had no other choice, I'll tilt the enclosure slightly to allow water to drain off.


Arranged to drain .

FWIW, we decided to enter the lower part of the enclosure.


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## bill39 (Sep 4, 2009)

While working in all types of heavy industry for many years, entering into the top of a cabinet was generally frowned upon.

It seemed like no matter what type of connector or sealant was used oil, water, or whatever would eventually get inside and reek havoc by blowing something or whatever.


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## Wirenuting (Sep 12, 2010)

gpop said:


> Old guy taught me if you can not make it waterproof make it leak.


Old guy told me the only two things waterproof are submarines and a ducks ass and everything else must leak.


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## Southeast Power (Jan 18, 2009)

They went for the bottom


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## bill39 (Sep 4, 2009)

The last waste-water plant I worked on the specs required the EC to enter the side of the cabinet and use a Tee instead of an LB so water could leak out the bottom of the Tee.


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## TRI0N (Aug 7, 2020)

Southeast Power said:


> We are installing several NEMA 4X stainless combo starters outdoors.
> I usually try to enter the enclosure near the bottom side below any of the interior components.
> It would be very simple to enter the top using a Myers hub. The lower side would require LBs and LRs. We have both on the job.
> Question:
> Are NEMA 4X enclosures typically entered in the top, or is that a possible problem. All of the conduit work is GRC.


They make PVC coated ones for outdoor for top. Pricy but do a great job. @ $70 a pop for quality.


Cheers!

TRI0N :vs_cool:


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## TRI0N (Aug 7, 2020)

bill39 said:


> While working in all types of heavy industry for many years, entering into the top of a cabinet was generally frowned upon.
> 
> It seemed like no matter what type of connector or sealant was used oil, water, or whatever would eventually get inside and reek havoc by blowing something or whatever.


Yeah I don't do it unless there is no other option. I use PVC Coated and a rubber gasket on the outside. Don't over tighten or it will just ruin the seal. 


Cheers!

TRI0N :vs_cool:


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## macmikeman (Jan 23, 2007)

You know, I don't really get to do awesomeness of such wonders as waste plant jobs (well , I have done a few but certainly not in a hell of a long time.). So anyway, what I can say is I have done a boatload of top entry into 3R rated enclosures- Meter/main boxes and outdoor rated electrical panels , 3R pull boxes, Bell Boxes, stuff.......... Some come with factory hubs , some you have to make your own ko's. I usually use a Myers hub in that situation. Mine never leak. Never. And I live in a place that gets rain like you never experienced, even in Seattle. Look it up on your internet where the rains hit. Some nights we get 14 inches of rain in a single night. And sometimes that goes on for weeks like that in the monsoon season. Next island over is Kauai . That place holds the worlds record of wet for civilization (there may be worse places in the boondocks but no real measuring going on there) . I don't seem to get leaks thru the top holes. Rust holes- yes, all the time. Don't scratch up the top of the cans. So what I wanna know is what are you industrial guys doing wrong that you get leaks thru proper hubs mounted in the top of outdoor cans?


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## Southeast Power (Jan 18, 2009)

Its always the environment.
Our situation isn't that unusual except that we are working on a school job with what can only be described as maybe 70% plans that truly reflect the work to be done.
The contract calls for us to catch any mistakes and report them up the food chain to the Project Architect. This is what we call the abyss.
I was very reluctant to be working on this project, to begin with. It ties up about 20k in labor per month, they pay every 5 months and are very demanding.
I found that other subs will work up to a key point and then stop work until they get paid.
One case were those 4X starters. I sat down with the contract admin and had them specifically exclude and motor controls, VFDs. There is also an equipment schedule that shows who provides the controls. Its the Equipment provider, on this job, its Trane.

Big panic ensues. Trane, DOES NOT CARE. 

John, can you get them.
Of course, Ill get a quote.
I will be very clear and state they didn't get the price column I would have got. 
I had them in about a week. 
The factory shipped them UPS Ground. 
The GC paid COD. :vs_laugh:
If I would have paid for them, I would have never been reimbursed.


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## gpop (May 14, 2018)

macmikeman said:


> So what I wanna know is what are you industrial guys doing wrong that you get leaks thru proper hubs mounted in the top of outdoor cans?


Every few months plants get walk around's and inspections so the operators pressure wash and paint everything to make it look clean and shinny. Add chemicals that will dissolve cheap rubber and you start to see problems.

TBH waste-water isn't that bad compared to food grade plants. Orange juice eats rubber/aluminum hubs/unprotected steel and the operators are washing down 24/7. 
If you live in a hot area you also have a problem with moisture being pulled into the conduits which leads to water dripping down the cables. On a meter can a few drips of water wont cause much of a problem but on top of a starter/breaker a few drips is all it takes to release the magic smoke.


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## 460 Delta (May 9, 2018)

gpop said:


> Every few months plants get walk around's and inspections so the operators pressure wash and paint everything to make it look clean and shinny. Add chemicals that will dissolve cheap rubber and you start to see problems.
> 
> TBH waste-water isn't that bad compared to food grade plants. Orange juice eats rubber/aluminum hubs/unprotected steel and the operators are washing down 24/7.
> If you live in a hot area you also have a problem with moisture being pulled into the conduits which leads to water dripping down the cables. On a meter can a few drips of water wont cause much of a problem but on top of a starter/breaker a few drips is all it takes to release the magic smoke.


Don't forget fork truck operators that ["I just barely touched that"] hit, pull, and bend conduit runs and millwrights use of conduits as lifting points to get a job done.


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## macmikeman (Jan 23, 2007)

460 Delta said:


> Don't forget fork truck operators that ["I just barely touched that"] hit, pull, and bend conduit runs and millwrights use of conduits as lifting points to get a job done.


This have anything to do with top entry of conduits?


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## 460 Delta (May 9, 2018)

macmikeman said:


> This have anything to do with top entry of conduits?


Well yes, in an industrial setting a conduit can enter an enclosure inside a building or outside and conduit can bent and hit way over there causing it to be moved over here, ya see?


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## Knightryder12 (Apr 4, 2013)

Southeast Power said:


> Its always the environment.
> Our situation isn't that unusual except that we are working on a school job with what can only be described as maybe 70% plans that truly reflect the work to be done.
> The contract calls for us to catch any mistakes and report them up the food chain to the Project Architect. This is what we call the abyss.
> I was very reluctant to be working on this project, to begin with. It ties up about 20k in labor per month, they pay every 5 months and are very demanding.
> ...


This job sounds early familiar. If you don't mind saying, what part of FLA are you in? Or what part of FLA is this job ini?


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## Southeast Power (Jan 18, 2009)

Knightryder12 said:


> This job sounds early familiar. If you don't mind saying, what part of FLA are you in? Or what part of FLA is this job ini?


Coral Springs Florida.


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## kb1jb1 (Nov 11, 2017)

macmikeman said:


> map costs extra


I remember the old scotchkote that last forever. All this new eco-friendly stuff does not hold up. I also remember when they banned the original here in NY, many contractors went over to NJ to buy the old formula version.


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## Knightryder12 (Apr 4, 2013)

Southeast Power said:


> Coral Springs Florida.


Not the project I was thinking about. But its crazy how that stuff happens.


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## Southeast Power (Jan 18, 2009)

kb1jb1 said:


> I remember the old scotchkote that last forever. All this new eco-friendly stuff does not hold up. I also remember when they banned the original here in NY, many contractors went over to NJ to buy the old formula version.


You cant forget that stuff is conductive when its wet.
I watched a guy dip some 277 volt splices while holding the can.
It was one of those great nasal exhales you hear when someone gets hit.
Also,
The can will tip over in your truck and leak out.
I don't keep an open can in my truck. I toss them.


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## gpop (May 14, 2018)

Southeast Power said:


> You cant forget that stuff is conductive when its wet.


Thanks for the tip i did not know that.
I will store that memory right next to contact cleaner is flammable and eye brows take a month to grow back.


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## Jarp Habib (May 18, 2014)

We've got a lot of 4X disconnects on our roof for the labratory exhaust fans. All bottom entry.

Each one of them is in varying stages of rusting out. I suspect that there is enough air transfer through the conduits from inside the building to allow the condensation to get trapped and build up.


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## MotoGP1199 (Aug 11, 2014)

Jarp Habib said:


> We've got a lot of 4X disconnects on our roof for the labratory exhaust fans. All bottom entry.
> 
> Each one of them is in varying stages of rusting out. I suspect that there is enough air transfer through the conduits from inside the building to allow the condensation to get trapped and build up.


Duct seal really helps out in these situations.


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## Quickservice (Apr 23, 2020)

macmikeman said:


> map costs extra


You stole my thunder... I was getting ready to suggest that. :biggrin:


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