220V Outside disconnect box, height above ground level requirements? 2

[Paul Kinzelman]

Sorry for such a basic question, but I've looked in the NEC book and can't find the answer, so I'm hoping somebody can point me to the right section that talks about this.

I need to mount a disconnect box on the outside of my house for a 220V/30A run to power a sewer grinder pump.

It would be *very* convenient if the bottom of the box being 2-ft above the ground level would OK according to the NEC code.

I live in NM if that makes any difference.

TIA!

BTW, I'm curious as to what the difference between the IEEE/NEC code (which is what I think I need), and the IEC electrical code because there's a different forum for that.

 

[waross]

The codes tend to change as you move from continent to continent and country to country. IEC is mostly European and countries or areas electrified by European countries.
There are exceptions.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[BlackJackJacques]

Min of 18-inch to bottom of receptacle box is trade practice for garages iaw NEC. The application will dictate whose code you will use, ie. ADA, health facilities, etc. Flooding, snow, and application will drive where you put box. In your case, you want the box up off the ground at least 18 inches and where you can easily see and reach it. In my case here in VA, I place my outdoor in-use boxes, including welding receptacles, disconnects (as well as other utilities - air, etc) about waist height so I don't have to bend down so much. You should ask your building code folks to get better guidance. IEEE and the NEC should be the same because of certain harmonizing activities that purposefully place folks on NEC panels on IEEE committees and visa versa. Same with IEEE and IEC, although there are certain stubborn differences but not in most cases.


GL

 

[Paul Kinzelman]

I was wondering if the code actually said anything about the height. It'd be *very* convenient if I could locate the bottom of the box 2 feet off the ground level so I could just have the cable go thru the wall directly into the box. It's just a sewer grinder pump disconnect so no need for ADA issues, etc., and I don't expect to use it very much, at least I hope not.

I can't really ask the code people, NM is one of the stupid states where they won't talk to you, you're supposed to have an electrician do everything or take a trivia test to be able to pull your own permit. The questions are very obscure NEC code questions, nothing about what you really need to know when doing common wiring tasks. It's made so that most people won't bother with it.

 

[BlackJackJacques]

I don't see why you can't install it 2 ft above the ground. Convenience and access are legitimate factors and in your case, there is not a degradation of safety, etc. As long as the disconnect is in proximity and within sight of the pump, you should be fine.

 

[Paul Kinzelman]

Thanks for the encouratement!
I'm mostly interested in protecting myself in case the electrician decides to be ornery about my putting in the box for him to wire the rest of the way to the sewage pump. In NM, after all, mere mortals such as myself aren't even supposed to wire a phone from one room to another!

If he complains, I wanted to be ready to be able to quote the electrical code where it says it's OK. I remember it talking about a maximum height someplace, but no minimum height so I was hoping somebody could point me to where it talks about that if it does. Like does the code allow the disconnect to be 6 inches above ground? I wouldn't think so, but I can't find it. But in reality, what I want is for a 2-ft height to be OK.
Thanks!

 

[BlackJackJacques]

Lifted from Mike Holt's

https://www.mikeholt.com/mojonewsarchive/NECQ-HTML/HTML/NEC_Questions006~20030523.htm

"The NEC does not mandate a minimum mounting height for panelboards, disconnects, or meter enclosures. But switches, and circuit breakers used as switches, shall be installed so the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 6 ft 7 in. above the floor or working platform [404.8(A)]. Exception No. 2 permits switches and circuit breakers used as switches to be mounted higher than 6 ft 7 in. if they are located adjacent (next) to the equipment they supply and they are accessible by portable means.

Note: 550.32(F) requires the outdoor mobile home disconnect to be installed so the bottom of the enclosure is not less than 2 ft above finished grade or working platform."

If your electrician becomes ornery - fire him or her. You should just tell him what you want and where you want it. If there is a code conflict, then he or she should
ID the conflict and provide the cite - otherwise, they should get busy and make the install.

GL

 

[Paul Kinzelman]

Yes, I think that's the section I found (which specified max height), but I didn't find the 550.32(F), tho that says 'mobile home' so maybe that doesn't apply. So it sounds like the code would allow it to be mounted 1 inch above ground level, tho that would be stupid of course.

It's more complicated than just firing him. The electrician I'm concerned about will be hired by the town and is contracted for the part between the box on the house and the outside pump. I'm responsible for the part between my service panel and the disconnect box so he has to be willing to connect to my part. When I was in CA, I could do my own wiring and did so. When the inspector came, he asked me who did the wiring because it was such a good job. I know how to do wiring, but I'm not conversant with the myriad of minutia of the code, thus my question.

Thanks!

 

[BlackJackJacques]

The relations between the town, the electrician and yourself seems a bit odd for the US and even odder for New Mexico - but if that is what they do..... Things to keep in mind: Different jurisdictions don't always adopt the latest edition of the NEC. I have seen some jurisdictions stuck back in the 1970 editions. I have also seen jurisdictions not invoking the NEC at all -- remaining silent on what they want, or providing their own prescriptive requirements. You may want to peruse the web page of whatever building authority you are governed under as a means of teasing out what is the standard of care for you. Mark Early of the NFPA 70 (NEC) will bombastically state at committee meetings "that the NEC has been adopted in all 50 states +" While that may technically be true since if just one entity in any state adopts the 1989 NEC edition - it may satisfy that declaration, even though the other entities may have other or no guidance at all. However, you certainly won't find All US+ entities adopting the latest NEC edition.

However, I still think you should be fine with the 2 ft height - provided there is no other issue such as maintenance clearances, etc.

Good luck

JR

 

[Paul Kinzelman]

Thanks very much for your help!

The situation is a bit odd (some say it's because I'm odd . I'm not implementing the sewer for just my house. The town is implementing sewer for the whole town (eventually) and they contract for a flat fee for contractors to come in and install sewer for all the houses in the town. The fee does not include wiring inside the house. I'm responsible for providing a 200V/30A circuit to a disconnect box, thus my question.

AFAIK, NM has implemented the NEC code with a few modifications which are more restrictive than the standard code book. But I don't think those extra items affect what I'm doing last time I looked.

 

[VladChiefns830]

Like the others have said, there is a minimum height requirement for disconnects. But it is only found in Article 551 (mobile homes, manufactured homes, etc.)

550.32(F), 2017 NEC

You mention though, that this work is being done as part of a town project. They may have their own local regulations and ordinances for how high that disconnect is supposed to be, for when the electrician comes to work on it and finish up the wiring. It's probably stated in a contract (somewhere).

 

[Paul Kinzelman]

That's an interesting idea, but I doubt that it's in the contract. I think they're more worried about the cost and getting bids, none of them are knowledgeable electricians.

But in any event, it's now mounted 2 ft, so I hope they'll like it. If not, it can be moved higher and then conduit the wire to the higher location if necessary.

Thanks for all your ideas!

 

[BlackJackJacques]

Please let us know how it turned out!

Thanks

 

[Paul Kinzelman]

Well my part of the project turned out just fine. The box is on the side of the house and it's temporarily wired in to run the current septic pump. The real question is what the electrician will say when he shows up. There's no schedule for it, could be months away. The project has been oozing along for several years already.
Thanks for your interest and help, and of course the moral support!

 

[BlackJackJacques]

Thanks & UR welcome