Can NEMA 3R switchboard in a dog house be equivalent to NEMA 4X switchboard?

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fandi

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Location
Los Angeles
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Electrical Engineer
Hello All,
It's less than 0.25 mile from the beach and I wonder if a dog house can be built around a NEMA 3R switchboard because NEMA 4X cost is too much. There are two louvers on each side which I'm afraid salty moisture can sneak in. Also I'm not sure this would void manufacturer's warranty. I appreciate your input.
 
Sure, but "dog house" needs to be large enough to allow proper 110.26 working clearances. I find it a little hard to believe if the only reason is to enclose a switchboard or panelboard that you can't get a 3R or even 4/12 enclosure for less then it costs to add the building around it.

Salt in the air still will get into a 3R panel.

Salt in the air will still be inside the "doghouse" unless you make it very airtight and almost never go in there. It may be at lower level then outside quite often and that could possibly prolong the life of equipment though.
 
jumper said:
And "dog house" is slang for...?
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Pre-fab building often used to enclose equipment outdoors, especially electrical equipment.

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Some fabricators build "non walk in" style wraps that seal the units fairly well, but if ANYTHING inside needs ventilation, salt air will get in. The only viable option is totally sealed with air conditioning. I just went through this exercise in Monterey, looking at all available options for an MCC near the ocean. After a lot of trial balloons, they ended up just building a CMU structure, it was cheaper.
 
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I have looked at using shipping containers but it always seems like just having a more conventional structure usually ends up being most cost effective.

I am not sure that even a type 4X panel board does as much for you as you might think.

You might want to look at other electrical equipment in the area and see how it has fared. it might be that it does not matter much if you use type 4X or not.
 
jumper said:
And "dog house" is slang for...?
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My guess for OP is small structure that may sort of look like a miniature "house", and also similar to the traditional structures used to house some of our canine friends, but in his application as I had mentioned - needs to at least be large enough to comply with 110.26, so we are talking a house for a great dane, not a pomeranian:)
 
Thanks everyone. I think CMU structure with adequate working clearance for the gear seems to be the best option.
 
fandi said:
Thanks everyone. I think CMU structure with adequate working clearance for the gear seems to be the best option.
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I guess I figured "dog house" would be rather inexpensive construction method, like wood skeleton and sheet metal covering it:huh:

Especially when you seemed to indicate in OP that a 3R rated enclosure would be too expensive - sorry you said 4X
 
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