# Myers Hubs and EMT



## HackWork (Oct 2, 2009)

I don't understand the point of using a meyers hub at all if you are using a compression connector. It's just one more point of failure.


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## Easy (Oct 18, 2017)

That's logical. It would be nice if I could find a raintight panel that has threaded entrances at the top but I'm probably just dreaming. I'm just looking for a practical way to come out of the top of a panel in a damp location. All of my runs will be heading up. LB's and 90 deg bends coming out the sides seems lame to me. U Bends out the bottom of the panel is real lame. Thanks again for the info. By the way that is a EMT compression fitting not a raintight fitting in that myers hub. Looks like it? Maybe it's Canada? The fitting I see and use where I am are usually blue anodized.


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## HertzHound (Jan 22, 2019)

If it’s only a damp location, why not use a sealing ring?

https://www.bptfittings.com/store/raintight-fittings/liquid-tight-sealing-rings.html


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## telsa (May 22, 2015)

Back in the day, rain-tite was not REALLY rain tight.

That's when Meyers hubs became spec'd.


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## Easy (Oct 18, 2017)

I really like the sealing ring as a solution for entering a non threaded enclosure. HertsHound even gave me a link. Thanks.. A meyers hub is also a good option but would cost more. EMT rain-tight connectors have the rubber washer without the outer metal ring and they really suck. You can't even tighten the fittings without driving the rubber washer out. I think the yellow washers are made of a hybrid material of some kind and don't seem to compress as much. Not sure about the details .. see photo


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## Easy (Oct 18, 2017)

telsa said:


> Back in the day, rain-tite was not REALLY rain tight.
> 
> That's when Meyers hubs became spec'd.


By design Myers hubs work great for keeping water out. The o-ring is kept in place by the inner groove. EMT connectors (like the ones in the photo I posted) have a tapered end and that causes the gasket to be pushed outward when they are tightened down. I have been reading the description for intended use and both the sealing ring and Myers hub say they are for use with IMC or RMC and there is no mention of EMT. It's really not a big deal and I know I am getting picky but I'm just looking for best the method. 
Myers hub pipe dope and then EMT conn.. :vs_laugh:


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## varmit (Apr 19, 2009)

I have used both Meyers hubs or sealing rings for top entry. Anything can leak, but I know what you mean about coming out of the side of an enclosure. If the panel is located somewhere where it is directly exposed to rain/snow, then side entry is the best option.

If you are using EMT, I have had good results with the sealing rings and raintight connectors. 

I did a crude test once (3 repeats) where I took two NEMA 4 enclosures: In one was a Meyers hub with a pipe plug installed. In the other, was a short rigid nipple with a pipe cap and double locknuts on a sealing ring. I set both on a piece of cardboard and let them set for about 30 minutes. The sealing rings did not leak any. The Meyers hub probably leaked 3 or 4 drops. 

The sealing ability, of a Meyers hub, seems to be influenced by the flatness of the surface on which it is installed, maybe more so than a sealing ring.


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## tmessner (Apr 1, 2013)

We seem to have as much trouble with water getting the conduit from some other place, then running throught the conduit and down into the panel. I think water or raintight means water in, not out. We avoid top entry if at all possible so water cannot follow the wires into trouble.


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## Southeast Power (Jan 18, 2009)

HackWork said:


> I don't understand the point of using a meyers hub at all if you are using a compression connector. It's just one more point of failure.


We wouldn’t do this on 3R.
NEMA 4X I wouldn’t have a problem doing that.


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## Easy (Oct 18, 2017)

I might have to go with a higher ratting than 3R for my application. It's indoors but the area I was planning on setting the panel might be considered a hose down area and I would have to go with a Nema 4 or IP65 enclosure. My best option would be to find a better location for the panel. Maybe inside an electrical closet or on the other side of the wall where it's dry. Often times the EE will just specs out a non raintight panel as I have often seen in areas where they should not be, like machine shops that use coolant and it's spays all over standard electrical panels. Why take chances.


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## Easy (Oct 18, 2017)

tmessner said:


> We seem to have as much trouble with water getting the conduit from some other place, then running throught the conduit and down into the panel. I think water or raintight means water in, not out. We avoid top entry if at all possible so water cannot follow the wires into trouble.


Oh how true. Electrical gear in basements or underground vaults and conduit systems that penetrate the roof. I always blame it on the plumber.


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## Easy (Oct 18, 2017)

I guess my jokes are not that good. Here is a valid example of how I have seen water getting into a panel through a raceway. Just one example. I talk too much.

1. Fan room in large engineering complex that used high temp and chilled water for heating and cooling. This happened all the time where I worked. Needless to say the fan rooms / mechanical rooms were adjacent to the electrical vaults that thankfully had floor to ceiling concrete. Anyways the pipping to the high temp lines often times failed and steam filled the room and the halls and office areas. Panels flooded with steam before anyone was aware if it. Especially in off shift hours. Even with heat detectors and security guards calling a plumber it takes time to respond. Security knew better than even open the doors. **** happens all the time.


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## paulengr (Oct 8, 2017)

3R is just weather tight NOT water tight. That’s why there is a small hole some place in the bottom. 4 is spray proof as in you can go at it with a fire hose and not get water in but it’s a huge condensation magnet. 12 is oil tight for machine shops. Only 6P is truly water tight but rare and expensive.

Contrary to popular belief even RMC is NOT water tight. If nothing else because the threads are actually slightly loose so you can actually screw it together. Pipe fitters use anaerobic thread sealant (best) or pipe dope or Teflon tape to seal that thin gap. More than once in industrial plants water got into the conduit from a broken sensor or a flooded deck
and it ran down into the 4X box.

A trick we used in mining and I’ll grant you it’s not Code (it’s a mine...Code is a guide not regulation) and it’s basically home made sealing rings is run a bead of silicone caulk on both sides of the conduit entry. Install two reducing washers upside down (wider side faces box). Then conduit nuts and plastic bushing or grounding bushing. The reducing washers create a small round silicone caulk filled box, essentially a home made sealing ring. In the same plant we also often bought the NEMA 4 or 4X box then drilled a 1/16” hole for water drainage basically for better gaskets on a NEMA 3R. Today you can buy a one way breather from Hoffman that works even better.

Not sure with the little set screw you can truly seal EMT. You have a better chance with the compression fittings but it’s not really supposed to be sealed and neither is even RMC. That’s why Rob Roy and the successors to it came around. Honestly tray and TC or TC-ER with CGBs makes a far better seal. It just won’t look like a pipe fitter did it.


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## bill39 (Sep 4, 2009)

If your mind is set on using a Myers hub at the box then why not make the last stick of pipe rigid?


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