factory holes in boxes

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autecbernie

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We installed a nema 3R safety switch out doors but we didn't use the factory mounting holes. An inspector saw this and said that those holes can't be left open. Is he right or isn't it the fact that it's a nema 3 R box and it's made to be outside. If these is a code for this could you tell me what it is
 
Re: factory holes in boxes

If the mounting holes are above current carrying components then I may agree with the inspector: the holes cannot be left "open" to the weather. But that is not the same as saying they must be used.

Look at the requirements for UL/NEMA 3R enclosures not at the NEC directly.
 
Re: factory holes in boxes

I would have to agree with the inspector if you leave these mounting holes open then you have defeated the purpose of the RT designation. Won't water enter through these open holes? What would be the difference if you leave a KO opening unplugged or a mounting hole open, water does not discriminate it will enter through any open hole.
 
Re: factory holes in boxes

How is using an anchor stopping water from entering, ie "using" the hole.

Anyone that thinks a 3R is waterproof is mistaken.
 
Re: factory holes in boxes

How is using an anchor stopping water from entering, ie "using" the hole.
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Have you ever noticed the little cork bushing insde a RT box, its there to seal the hole.

Anyone that thinks a 3R is waterproof is mistaken.
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Why then use a RT box, all the RT panels, boxes etc. that I have installed I can go back a year later and find no sign of water entering the RT box. Besides it is up to the installer to make sure the RT box is RT after installation.
 
Re: factory holes in boxes

Originally posted by Jhr:
Anyone that thinks a 3R is waterproof is mistaken.
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Why then use a RT box, all the RT panels, boxes etc. that I have installed I can go back a year later and find no sign of water entering the RT box. Besides it is up to the installer to make sure the RT box is RT after installation.
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jhr I agree with jes 25, raintight is not water proof, if you want water proof you need to move from NEMA 3R to NEMA 4 or better.

Check out Jim D's post, he knows UL listing info better than many.

I agree with Jim that only the holes above the current carrying parts need to be closed in some manner.
 
Re: factory holes in boxes

Originally posted by b connection:
Why not just throw a little duct seal on the mounting holes and be done with it?
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What fun would that be. :D


Actually that was the best answer so far. :cool:
 
Re: factory holes in boxes

Why do these threads always seem to go into a downward spiral and the original ? never gets an answer. If its RT then to me it would be waterproof, what makes RT boxes not RT (waterproof) is the installer neglecting to seal off any opening,(as I stated in my first response), that could allow water to enter the box. The designation RT or waterproof means just that, no water is to enter the box in any way.

Anyone that thinks a 3R is waterproof is mistaken.
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I guess we are been fooled by the manufacturers :p

[ February 19, 2006, 11:13 AM: Message edited by: Jhr ]
 
Re: factory holes in boxes

JHR, I did not write the standards I just live with them like the rest of us. :) NEMA 3R is not considered watertight.

NEMA 3R

Intended for outdoor use. Provides a degree of protection against falling rain and ice formation. Meets rod entry, rain, external icing, and rust-resistance design tests.
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NEMA 4 and 4X
Watertight (weatherproof). Must exclude at least 65 GPM of water from 1-in. nozzle delivered from a distance not less than 10 ft for 5 min. Used outdoors on ship docks, in dairies, and in breweries.
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More Info can be found here

And here
 
Re: factory holes in boxes

JHR,
The "rain tight" or 3R standard permits water to enter the enclosure as long as it does not come into contact with the energized parts. That is why 3R enclosures have drain holes...to let that water out. You need to go to a NEMA 4(watertight) or 6 (submersible) if you don't want water in the enclosure.
Don
 
Re: factory holes in boxes

JHR

NEMA 3R means that the device can be mounted in falling (and slightly windblown) rain and it's operation will not be adversely affected. Any water (including condensation) that may enter the enclosure must drain out. Holes including knockouts are allowed if they are below current carrying parts. The paint of the enclosure must also be UV stabilized. Gaskets are not required.

This has been the basic definition since before I entered the business back in '78. UL even incorporated the NEMA standards as part of their listing requirements, so now most manufacturers refer to the rating as NEMA/UL 3R.
 
Re: factory holes in boxes

Back to OP.
If you did not use factory holes for mounting, what did you do?? Did you provide the 1/4 inch air space behind the enclosure?? Did you provide equivalent sealing to equal the cork gasket?? Those are things I would be looking for.

Here are NEC def. for reference and comparison to what has been quoted from NEMA:

Rainproof:
Constructed, protected, or treated so as to prevent rain from interfering with the successful operation of the apparatus under specified test conditions.

Raintight:
Constructed or protected so that exposure to a beating rain will not result in the entrance of water under specified test conditions.

Watertight:
Constructed so that moisture will not enter the enclosure under specified test conditions

Weatherproof:
Constructed or protected so that exposure to the weather will not interfere with successful operation
(FPN): Rainproof, raintight, or watertight equipment can fulfill the requirements for weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor.

Note:
The "proof" definitions say nothing about water "not" entering the enclosure. You could a river running through it as long as it operates successfully.

The "tight" definitions mention specified test conditions. What test conditions??? I could test it in my backyard with a garden hose. Unless of course, it is required to be "listed" as raintight or watertight.
Raintight mentions entrance of water.
Watertight mentions entrance of moisture.

Interesting how NEMA lumps weatherproof and watertight together, but NEC does not.
 
Re: factory holes in boxes

Larry,

NEMA does not lump waterproof and watertight together. NEMA says a "tight" enclosure can be used to meet the needs of a "proof" application.

NEMA/UL recognizes there are differences between "tight", "proof", and "resistant"
Simplified examples:
NEMA type 3 - Dusttight, Raintight - has gasketing and external mounting provisions, undamaged by ice
NEMA 3R - Rainproof - gasketing not required, internal mounting allowed, undamageed by ice
NEMA 3S- Dusttight, Raintight, Sleet Resistant - has gasketing and external mounting provisions, can be operated while covered by ice.
 
Re: factory holes in boxes

Jim
I'm not trying to contradict anyone. I was going by the quote Bob had posted. I will have to go and bone up on all the NEMA X enclosures. It's been a while since I had to apply anything higher than 3R.

My point (although not clearly stated in my post) would be how the terms are easily mis-applied.
 
Re: factory holes in boxes

Mis-applied, Absolutely.

In reality there are usually no such general things like NEMA/UL "----tight", "----proof" or "----resistant". These are typically marketing terms.
 
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