I have been told that a residential outdoor a/c unit must be located 3 feet from an outdoor electrical panel box (electrical service). I was wondering if there was a code reference on how far a disconnect for a residential back up generator needs to be from the same outdoor a/c unit. You guys have been fantastic source of info for years. thanks
outdoor back up generator disconnect and outdoor a/c unit
- Thread starter difowler1
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Cavie
Senior Member
- Location
- SW Florida
It's not a matter of one thing being any distance from another. It's a matter of working clearance of the panel or disconnect.
disconnect
disconnect
You need 30" of working space from side to side, not neccesarily measured from the center of the disconnect, but 30". So if you had an a/c unit then the disconnect for the generator and then the generator itself all along one wall, they would all 3 need to be spaced 30" apart I guess
disconnect
You need 30" of working space from side to side, not neccesarily measured from the center of the disconnect, but 30". So if you had an a/c unit then the disconnect for the generator and then the generator itself all along one wall, they would all 3 need to be spaced 30" apart I guess
- Location
- Placerville, CA, USA
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- Retired PV System Designer
Nope. The 30" of working clearance (measured side to side) can be shared among pieces of equipment.
So if I have a 36" panel and two 24" panels on either side of it (right up against it), the working space for each of the 24" panels can overlap the 36" panel between them and not have to extend beyond the outer edge of each 24" panel. One clear space of only 84" width provides the 30" clearance for all three panels.
- Location
- Massachusetts
Correct, the measurement can start at the side of the equipment not the center.
The generator and the AC unit would have to be 30" apart minimum, the disconnect could be right beside either of the units.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
I think you are saying this because the generator and the A/C unit will each need access from the side as well as from the front, yes? Otherwise they would just have to be spaced far enough apart that one of them does not interfere with with the 30" wide and 36" deep working space in the front of the other.
If the generator, for example, needs side access for maintenance, then I believe that you would need 36" and not just 30" between generator and A/C.
And although the disconnect could be mounted right next to either one, the fact that the A/C and the generator extend away from the wall prevents any overlap of the disconnect access space width from overlapping either the generator or the A/C.
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- Location
- Massachusetts
No, I am saying this because the OP stated their was a disconnect between them.
I had not considered equipment access at all but that is also something that should be taken into account.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Good point!
Now if the disconnect was on a pedestal flush with the part of the generator and A/C farthest from the wall, then the access space could overlap.
But if the disconnect is mounted on the wall, then the A/C and generator would not be allowed to intrude on the 30" space the disconnect defined between them.
- Location
- Massachusetts
I agree possible but now you get into equipment access requirements as you mentioned above.
I just locate the disconnects 49 feet to the side to make sure they are not in the way.
kwired
Electron manager
- Location
- NE Nebraska
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- EC
I don't see where working spaces are prohibited from overlapping.
Example of an electrical room would allow 36 inches between panels on opposite walls - as long as voltage or other conditions didn't require more then 36 inches of clearance anyway.
Now if you need to work on both pieces of equipment at same time it may be a good idea to consider more clearance.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
There is a difference between working spaces overlapping (when both pieces of equipment extend the same distance from the wall, i.e. flush) and one piece of equipment infringing on the working space of the other if it sticks out farther from the wall. The A/C can infringe on the working space of the disconnect while at the same time the disconnect does not infringe on the working space of the A/C.
Or both could infringe on the working space of the other, depending on what forms the other boundary of each working space.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I get that, I just can't say I ever recall running into a disconnect infringing on "work space" to an AC unit.
Cavie
Senior Member
- Location
- SW Florida
OK, I guess we got the op really confused now:?:roll:
That is one area where we excel !
dfowler, fortunately you answered your own question in post #2.
Also keep in mind there are various building codes that address the location of the generator and address issues such as structure materials, generator casing, overhand of eves, etc.
- Location
- Massachusetts
That is one area we excel !
Sadly we are great at that.
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