ECN Forum
Posted By: wewire2 Raintight EMT Fittings - 11/30/07 07:40 PM
The newer designed raintight fittings are more expensive than the ones used in the past which are now only rated concrete tight. In the interest of efficiency,
should these also be required by local inspectors when used for low voltage or Telco runs?
Posted By: sparkyinak Re: Raintight EMT Fittings - 11/30/07 08:44 PM
Yes, 800.110
Posted By: wewire2 Re: Raintight EMT Fittings - 12/01/07 12:08 AM
Ok so if the jurisdiction has only adopted the 2002 NEC and the 2004 CEC(California Electric Code) then technically it would not be required to use these?
Posted By: leland Re: Raintight EMT Fittings - 12/01/07 12:22 AM
Operate under the code/s in effect.

And how can a State like California be so behind? Don't they want to ban Fireplaces,correct "OZONE" and ahead of the curve on pollution? Massachusetts just wants to keep up with them.

I don't get it.
Posted By: renosteinke Re: Raintight EMT Fittings - 12/01/07 12:40 AM
The issue of 'raintight' connectors is not directly tied to any particular edition of the NEC. You need to use materials appropriate to the use.

The saga of the common compression fitting became a 'front burner' item the day some anonymous sort at UL actually tested some fittings to the 'wet location' test ... and they failed.

OOPS. The fittings everyone assumed were weather tight were not. UL revised the listing, and manufacturers scrambled to make a fitting that would pass the test. Some went a step further, and made some sort of indicator visible, for the convenience of the inspector.

So ... without regard for the code cycle your town uses, the old compression fittings are no longer considered suitable for use in wet locations; you need the new ones.

Since the code is not retro-active, there is no requirement to replace ones installed while they were still listed for the application.
Posted By: leland Re: Raintight EMT Fittings - 12/01/07 12:58 AM
there is no requirement to replace ones installed while they were still listed for the application.---

Would you not have to bring the portion retrofitted into compliance?

08' as I understand makes ALL outside apps. "wet locations".
Posted By: renosteinke Re: Raintight EMT Fittings - 12/01/07 01:21 AM
Correct .. what you work on today generally needs to meet today's rules. In this instance of fittings, I cannot see the 'maintenance' principles applying; it's not like you'ld have to pull a new wire!

Though, I must confess to being something of a hypocrite as to these newer fittings. They've been out for over five years - and I have yet to see one, let alone install one. Bridgeport, T&B, etal., seem quite happy to continue making the older style, and I'm not even sure the local parts houses have the newer ones on the shelf. Nor does it seem that the AHJ's are looking for them; that Reno is in the "desert" may be 'why.'
Posted By: wewire2 Re: Raintight EMT Fittings - 12/01/07 01:26 AM
We work all over Ca. Many supply houses haven't stocked the
Raintight fittings until recently. We finally found a jurisdiction that is requiring them and are now eating the cost difference. It seems crazy that you have to use rainproof fittings on a sleeve or a conduit that ends with an open end like at a ground rod. I also envision conduits prematurely rotting from the inside in certain instances. But then again maybe I'm biased because I'm losing a chunk of change.
Posted By: leland Re: Raintight EMT Fittings - 12/01/07 01:36 AM
eating the cost difference--

Why, Job start after the code change? or you not counting on the AHJ enforcing?
Code change makes price change.
There was a while here the bids were T&M due to copper prices fluctuating so rapidly.
Posted By: wewire2 Re: Raintight EMT Fittings - 12/01/07 03:20 AM
Hi Leland
It's really simple. I did not count on them enforcing it. The AHJ do not enforce it until they adopt it. When I am competing against other contractors, I don't add unnecessary costs to the job. It
reduces my chance of landing the job. In this case, I
did not do my homework and failed to investigate the
jurisdiction requirements. Code change might make the price change, but not instantly.
Posted By: gfretwell Re: Raintight EMT Fittings - 12/01/07 03:57 AM
I think this whole "raintight" is BS anyway. This is a wet location and if it is outside it will get wet inside. That may just be a Florida thing but it certainly seems true here. It could be humidity that cycles through the dew point most nights or it could be the sideways rain.
If U/L wants to test something they should try a bubble cover in a 40 MPH summer shower or just look at a bell box cover gasket that has lived in the sun for a couple years.

I imagine the whole thing is just trying to get us ready for GFCI protection on outside lighting. I am doing it on my patio but I am doing it with boxes that get water in them now and then. I have about a half mile of #12 THHN in EMT above ground and RNMC underground serving overhead lighting and receptacles. It is all on 3 GFCIs. First tip, always be sure the wirenuts are at the top of the box and pointing up.
Posted By: leland Re: Raintight EMT Fittings - 12/01/07 05:43 AM
WEWIRE2, I hear ya, Gotta hate the new territory or the new "sherif", sometimes it's just their mood. Some can be simpathetic to the finacial end some not. somethng like this (after install)some would let it slide.

Greg, good tips, Only takes a hundred trips to figure this out. Frustated customers help.:)
Posted By: ausador Re: Raintight EMT Fittings - 12/10/07 01:17 PM
Greg another tip for working with raintight boxes in florida......drill a 1/8" "weep" hole in the bottom corner of the box just in front of the hubs. This works fairly well to eliminate the box filling with water and much of the rust and corrosion associated with it.

How many "bell" boxes have you opened up that had a mixed rust/corrosion line on the interior of the box showing that it had been half full of water on more than one occasion?

Yes I suppose I am perverting the listing somehow by doing this but I have found it to be a good solution. smile
Posted By: sparkyinak Re: Raintight EMT Fittings - 12/10/07 04:36 PM
I live in a rain forest and bell boxes are used all the time here. The only time I usually have a water problem with a bell box is when they are put where they are subject to damage. The blank covers for them are not all that structurely sound and if you remove the cover you are better off replacing it with a new one because the gaskets gets stuck to the box and rip.

Another problem with them is the box holds a device like a recept and a cord is left plugged in so the cover can not close which allows moisture to get in. This is why closed while in use covers are required.

Both problems are the result of improper installation and use, not design of the boxes.
Posted By: ausador Re: Raintight EMT Fittings - 12/10/07 05:24 PM
The hubs leak, the conduit leaks, but the box actually is raintight. That is the problem, once water gets into the box it stays there....and does so for a long time usually.

The box needs a drain....I give it one....
Posted By: gfretwell Re: Raintight EMT Fittings - 12/10/07 09:49 PM
If the manufacturers really wanted these boxes rain tight they could spend another dime on the gasket. If this was a real rubber gasket in a groove around the perimeter like the big Carlon J boxes you might actually keep most of the water out but that would cost them a quarter.
Posted By: wire_twister Re: Raintight EMT Fittings - 12/11/07 01:32 AM
Good call Greg, it all comes down to money. I ran about 2000 feet of uf cable down the sides of a driveway, installing about 14 receptacles on uni-strut driven in the ground for, you guessed it christmas lights. Had a water problem with the gaskets on the in use covers, went back on more than one occasion to reset GFCI finally drilled a weep hole in each box, problem solved. Now the biggest problem I have is keeping fire ants out of the receptacles, anybody have a solution for ants?
Posted By: gfretwell Re: Raintight EMT Fittings - 12/11/07 02:30 AM
Make sure you put some duct seal in any conduit that dead ends in the ground. That is usually how the ants get in.
Posted By: leland Re: Raintight EMT Fittings - 12/11/07 04:08 AM
But now... I the MFGR installs weep oles, Some dope will install the box upside down and we're right back where we started!!! DOOOOOOHHHH
Posted By: ausador Re: Raintight EMT Fittings - 12/12/07 12:00 AM
MFGR could not and would not install weep holes as this would require another completely seperate listing by U.L.

Errrrr....something like "One sided Rainproof boxes arranged for drainage". lmao

You have noticed that they don't pretend that 3R pull/junction boxes are watertight havn't you? They all have a definate up/down orientation and cover....and weep holes!!!!!!!

Only the poor lowly 1 and 2 gang bell/reddot/T&B boxes are supposed to somehow be impervious to water and its affects. Another carryover from 50 year old codes that take no notice whatsoever of reality proven in the meantime.

All these boxes fill with water, the aluminum corrodes, the steel rusts, devices trip, and yokes corrode/rust off. Everyone in the trade knows it yet nothing is done....oh no we are too busy mandateing tamper-proof receptacles or some such equally important rubbish...Grrrrr.

Ok...let me take a deep breath or two....ahhh...all better now... smile

Weep holes drilled by the installer are an important and necessary means of making the installation long lasting and a trademanlike installation.

Thats about all I can say....do it right or do it wrong...it doesn't really take any more to do it right if you know what your doing....but you can do it wrong and then suffer through the callbacks....your choice I guess....
Posted By: earlydean Re: Raintight EMT Fittings - 12/12/07 08:18 PM
Check out the commentary to Section 225.22:

"Therefore, raceways should be installed to permit drainage through drainholes at appropriate locations."

This, to me, encourages the installer to drill drainholes at low points of the installation. By limiting the size to 1/8", most insects will be excluded.
Posted By: wewire2 Re: Raintight EMT Fittings - 12/15/07 01:33 AM
I was wondering about drilling holes in Bell boxes as far as the UL listing goes. The side mounted brackets they provide with the box are really flimsy. I usually install a couple screws through the back with a washer and some caulking. I just call them plugged drain holes to meet code.(ha) I also found that water seeps in through the hubs, so I always caulk those too. The boxes are designed so that when you screw the hub seal in all the way it leaves a nice little cup for water to sit. I guess if they made them any better they would cost more than 3 bucks.
Posted By: SolarPowered Re: Raintight EMT Fittings - 12/17/07 12:38 AM
Regarding hubs leaking, that's not defective fabrication--it's how the threads are designed. U.S. NPT threads do NOT seal--they have a spiral leak at the tips of the threads. That's why plumbers have to use either pipe dope or teflon tape on their threads.

This goes back into the 1800's, when the pipe threads were standardized. They could have specified the threads so that they would acually seal, but they didn't. There exist other threads that do actually seal. (I believe the BPT threads will seal without a sealant.)
Posted By: KJay Re: Raintight EMT Fittings - 12/17/07 03:47 AM
Solar Powered,
You bring up an excellent point about the threads on U.S. electrical equipment.
Most U.S. electrical equipment, hubs, connectors, EMT, rigid, IMT and conduit and fittings use what are called straight NPSM threads. These threads are known not to be reliably watertight at even slight positive pressure without the addition of thread sealant.
The NEC requires explosion proof equipment and conduits for classified locations such as, fuel pumps, to use tapered NPT threads like plumbers and gas pipe fitters use. NPT threads compress and lock together when tightened, so they are water and vapor tight and are also resistant to loosening from vibration.
Whenever I have to work with pipe, I always carry both types of dies in my threader kit, because once you get out of that classified location you can go back to using the factory NPSM threads that come on our rigid conduit. smile

As an example, this is why when you try to use a 3-foot long piece of 1/2 rigid pipe from the hardware store to make an extension pole for a ceiling fan, it does not thread properly into the fans hub. The fan hub in NPSM and the pipe is NPT.
Something that everyone has probably tried at one time or another in a pinch.
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