NEMA 4X enclosure
NEMA 4X enclosure
(OP)
Can you have ventilation openings for a NEMA 4X rated enclosure? Would that contratdict the definition of NEMA 4X, menaing splash-proof and protection against hose-down situation?
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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RE: NEMA 4X enclosure
If you are trying to vent it because of the heat loading then you should hunt down my dissertation on the subject. It's in here somewhere. I had to do several NEMA 4x systems for oil fields and pipelines that had cooling demands.
Keith Cress
kcress - http://www.flaminsystems.com
RE: NEMA 4X enclosure
RE: NEMA 4X enclosure
The main NEMA 4 test basically involves using a fire hose and spraying the crap out of the enclosure at almost every angle directing the stream at the seams and any possible place where water could enter. If there is any water found inside the enclosure then the test is a failure. I highly doubt you can come up with some type of vent which would block a fire hose stream and still be open enough to allow air to flow.
I suggest you use a 3R type of listing. This is still suitable for outdoor use and can be vented with suitable fans and hoods.
RE: NEMA 4X enclosure
So that said, it really depends on your application. A lot of people specify NEMA 4X enclosures simple because they are putting them outdoors in a corrosive environment, and there is no such thing as "NEMA 3X". So if that's your application, you would likely be fine with venting a N4X box as long as the vent is rated for outdoor (i.e. N3R) use, but if you need to ensure the UL listing of the box and the overall assembly, then it will not be possible as far as I know.
If you need heat rejection, there are N4X heat exchangers available, and I think there are now some Peltier Effect (TEC) air conditioners that are rated 4X as well. But traditional compressor type A/C units are not, to my knowledge, available with anything better than N3R, although you can get N3R with stainless steel components.
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RE: NEMA 4X enclosure
RE: NEMA 4X enclosure
You have to look at why it needs to be ventilated. If it is because someone thinks that would be 'nice' or the last box they saw was ventilated you may not need it. If on the other hand, it has to be cooled then you must do a thermal/dissipation assessment and work with that.
Keith Cress
kcress - http://www.flaminsystems.com
RE: NEMA 4X enclosure
What I have seen on similar installations is a "doghouse" style setup, with NEMA 3R gear mounted inside of another overall 3R structure around it. Both have ventilation, but water would need to be blown through the vents of the first enclosure and then again through the second one and then build up in the 2nd one to get to live components. the velocity of the wind blown water inside of the first box is significantly lower than what it would take to get it into the inner box. Not technically impossible, but a level of improbability that satisfies most people.
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RE: NEMA 4X enclosure
http://w
David Baird
Sr Controls Designer
EET degree.
Journeyman Electrician.
RE: NEMA 4X enclosure
Keith Cress
kcress - http://www.flaminsystems.com
RE: NEMA 4X enclosure
"Rube Goldburg" approach, but if it works, why not. We do need to think outside the "box" sometimes.
Alan
RE: NEMA 4X enclosure
Link
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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RE: NEMA 4X enclosure
Would the equipment fit inside a shipping container?
RE: NEMA 4X enclosure
I wish that the IP world had the same sort of classifications as NEMA have for enclosures. At least they determine "indoor" and "outdoor" use in the recommended designs.
RE: NEMA 4X enclosure
RE: NEMA 4X enclosure
RE: NEMA 4X enclosure
http://redapt2.axcess10.com/assets/182/001dpe.pdf
RE: NEMA 4X enclosure
I'm on the Oregon coast where we don't have hurricanes, just hurricane force winds. And it rains a bit here. Our crews keep their drill bits sharp for putting drain holes in equipment where the manufacturers thought "sealed" must be better.
RE: NEMA 4X enclosure
The discussion rasied an interesting point. If moisture is a main problem for NEMA 4X enclosure, how was it circumvented in the past? Other than an ingenius device like 7anoter4 has pointed out, is the only way to just drilled a drain hole like stevenal has stated? In areas where salt content is high, or it is known to be corrosive, is the drain hole still the better choice among all?
RE: NEMA 4X enclosure
And by NEMA, I mean UL now, because NEMA was not really a testing authority, so each manufacturer could make any claim they thought they could get away with. For that reason, UL adopted the NEMA Type Tests into their UL-50 (I believe) electrical enclosure standards. The device linked to above does not say it has UL Type 4X, although it does have CSA Type 4X so you could use it in Canada and in the US if you find an AHJ savvy enough to allow it.
But a weep hole? Not in 4X.
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RE: NEMA 4X enclosure
- Crouse-Hinds offers a NEMA 4X breather/drain. Installed properly, it will allow you to eliminate condensation from inside the enclosure while still maintaining a NEMA 4X rating. It doesn't provide much in the way of ventilation, but it's a good solution for eliminating interior condensation. We've installed these on NEMA 4X enclosures we've manufactured and have gotten good results.
- If you're looking to ventilate the enclosure and eliminate internal moisture, IceQube (http://www.iceqube.com) has a filtered fan package that is rated NEMA 4X. It can even be used in wash-down situations. We've designed and manufactured NEMA 4X enclosures using their equipment for a forced fan ventilation system, and we haven't heard any complaints or issues from our customers.
Just because it's a NEMA 4X enclosure doesn't mean it can't be ventilated or have moisture removal features.
Bison ProFab
http://www.bisonprofab.com