NEMA 3R SWITCHBOARD LOCATED OUTDOOR IN FLORIDA

[faresos]

Hello Everyone:

Can we use nema 3R switchboard located outdoor? The contractor is claiming the NEMA3R is not rated for high wind location such as hurricane. My understanding the NEMA 4X has to pass the hose down test which I think it's for different application such as wash down areas. The switchboard is already installed and it's surrounded by walls in the mechanical yard but open from the top. The building is about one-mile away from the ocean. Any thoughts?

Thanks,

 

[petersonra]

Hello Everyone:

Can we use nema 3R switchboard located outdoor? The contractor is claiming the NEMA3R is not rated for high wind location such as hurricane. My understanding the NEMA 4X has to pass the hose down test which I think it's for different application such as wash down areas. The switchboard is already installed and it's surrounded by walls in the mechanical yard but open from the top. The building is about one-mile away from the ocean. Any thoughts?

Thanks,

They normally are not rated for seismic zones either. But so what?

It might be there is some special rule in FL about such things. They do have some serious rules about hurricane resistance.

Type 3R anything tends to be about as flimsy as they get so the guy might be right about it not holding up to winds. There is also the plain fact that type 3R enclosures are not especially rain resistant when the rain is being driven sideways by the wind.

the cheapest solution in the long run might well be to put a roof over it. a concrete slab roof might be acquired for very little and set on the walls if you can get a structural engineer to sign off on it. I have seen that done before. But it was planned that way and not an afterthought.

I don't know that a type 4X unit would be listed for hurricane force winds either though.

 

[Jraef]

Hello Everyone:

Can we use nema 3R switchboard located outdoor? The contractor is claiming the NEMA3R is not rated for high wind location such as hurricane. My understanding the NEMA 4X has to pass the hose down test which I think it's for different application such as wash down areas. The switchboard is already installed and it's surrounded by walls in the mechanical yard but open from the top. The building is about one-mile away from the ocean. Any thoughts?

Thanks,

There is no "hurricane" rating for electrical enclosures. That's not to say type 4X would not be warranted in your situation, but you will not find switchboards that have a 4X rating, so really, it's a moot point. The only possibility is to have a stainless steel or fiberglass "wrapper" made for it, and in my experience, that will cost more than just building a cheap cinder block structure. In your case, it sounds as if it just means adding a roof!

3R is intended for use outdoors to provide a measure of protection against wind blown rain. 3R by the way does not say that water will not get it, as type 4 does. In 3R, it will just not be allowed to accumulate inside to where it comes in contact with any live components. Given that you already have walls around it, I think 3R is fine here. Just make sure you have good paint and that you prime and paint any nicks and scratches.

 

[Strathead]

Hello Everyone:

Can we use nema 3R switchboard located outdoor? The contractor is claiming the NEMA3R is not rated for high wind location such as hurricane. My understanding the NEMA 4X has to pass the hose down test which I think it's for different application such as wash down areas. The switchboard is already installed and it's surrounded by walls in the mechanical yard but open from the top. The building is about one-mile away from the ocean. Any thoughts?

Thanks,

I live in Florida and I think he is just making it up. If a designer wants something special they can spec and pay for whatever they want.

 

[dkidd]

Hello Everyone:

Can we use nema 3R switchboard located outdoor? The contractor is claiming the NEMA3R is not rated for high wind location such as hurricane. My understanding the NEMA 4X has to pass the hose down test which I think it's for different application such as wash down areas. The switchboard is already installed and it's surrounded by walls in the mechanical yard but open from the top. The building is about one-mile away from the ocean. Any thoughts?

Thanks,

I would be worried about salt corrosion.

 

[faresos]

Thank you all for the replies as they are very helpful. The intent of the hurricane application is the wind could be considered blowing side ways which I think that's its the concern since it might be similar application for the washdown event.

Thanks you all for the replies!

 

[Strathead]

Thank you all for the replies as they are very helpful. The intent of the hurricane application is the wind could be considered blowing side ways which I think that's its the concern since it might be similar application for the washdown event.

Thanks you all for the replies!

If a dog decided to pee on it you would have a similar result. I mean to be sarcastic to the GC you are referring to. A NEMA 3R enclosure is designed for the application you are referring to, period. Tell them if they want to pay more you will gladly install any more expensive enclosure they want to pay for, simple as that.

 

[petersonra]

I think 3R is fine here. Just make sure you have good paint and that you prime and paint any nicks and scratches.

And make sure it is on some kind of plinth and grouted so there is not water standing up against the base of the thing.