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NEC Clearance Requirements For Electrical Panels/Gear On Walls, Each Side, & Above/Below

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Prince Of Darkness

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For a completely off-grid system, just built a new Energy Wall -- 8 ft long X 84" high. This is not a lot of space for the backup power system in a cut down Cargo Container, which is only 10 ft long.

Looked at NEC 110.33, and see text and a drawing, stating that clear space around electrical panels, can share space needed for other panels (and probably devices, like CCs, Inverters, etc, I hope):

Mike Holt, pg 43

No inspection at this location is presently required, but would like to get reasonably close to recent/present Code.

Will be running several 600 V CCs, and will be close to providing 48" working space in front or equipment, but batteries encroach about 10" of depth (in front of this wall) along most or the wall's length.

Also, read somewhere, that no breaker handle (and, probably any other control?) may be more than about 77-ish inches above the floor. This implied that the upper part of an AC panel, might be permitted to exceed this height (hopefully without needing a service platform).

Thanks for advice, Later, 'Luke'.
 
Hi @Sticky1, and @Danke, thank you for the replies.

Thanks for the info, and drawing.

So, in the original post, I really did not ask any specific questions. But, if other panels, devices, boxes, etc can share some of the area surrounding any panel that needs clear-ish space;

1. What other types of devices/panels etc MAY share this area around the panel needing space? IIRC, the clearish space is usually 30" in width.
2. What other devices may be allowed to do such sharing -- SCCs? PV Disconnects, MidNite Epanels, etc, etc?
3. When adding additional panesl/devices which also require clearish space surrounding them on this energy wall, do they require a separate 30-ish inch wide clearish space surrounding them, or, are these additional panels/etc just continue along that wall, sharing the required space, and at the very last such deivce on the wall have clear space around it ??

I do realize that the intent of these provisions, really is mostly/all for worker safety, focusing on room to work safely, and space to react to Fault conditions.

I appreciate any claritty that folks who know the Code, as I know almost nothing of Code details. Am trying to get as close as is reasonably possible, given the fairly small area and volume available.

Thank you, again, Luke
 
Prince Of Darkness said:
Hi @Sticky1, and @Danke, thank you for the replies.

Thanks for the info, and drawing.

So, in the original post, I really did not ask any specific questions. But, if other panels, devices, boxes, etc can share some of the area surrounding any panel that needs clear-ish space;

1. What other types of devices/panels etc MAY share this area around the panel needing space? IIRC, the clearish space is usually 30" in width.
2. What other devices may be allowed to do such sharing -- SCCs? PV Disconnects, MidNite Epanels, etc, etc?
3. When adding additional panesl/devices which also require clearish space surrounding them on this energy wall, do they require a separate 30-ish inch wide clearish space surrounding them, or, are these additional panels/etc just continue along that wall, sharing the required space, and at the very last such deivce on the wall have clear space around it ??

I do realize that the intent of these provisions, really is mostly/all for worker safety, focusing on room to work safely, and space to react to Fault conditions.

I appreciate any claritty that folks who know the Code, as I know almost nothing of Code details. Am trying to get as close as is reasonably possible, given the fairly small area and volume available.

Thank you, again, Luke
Click to expand...
If everything is the same depth (+/-), it can share the same 30" working space horizontally. You would not want to have a 18" deep piece of equipment on either side of a panel without a full 30" width in front of the panel. The code now has some exemptions for things like wireway being deeper but I don't remember the precise details. (so on #3, no "dedicated" 30" width per panel)

The code intent for panels is also to make sure there is adequate space for conduit to enter the enclosure (clear on the wall from floor to ceiling). You can put more things in there as long as it does not interfere with a clean installation. But, anything the electrician installs is essentially fair game as long as working clearances are maintained.

Generally, I would try to arrange panels and equipment so there is clean flow and short conduits; going right to left on a wall I might have the panelboard, inverter, PV disconnect, and then battery if there is one. I would stack the solar charge controller and PV disconnect, and if there is enough space above/below the inverter I would put communications electronics and similar accessories. If the "front" of a server rack battery (the clear working space) needs to share the workings pace of the panels and inverters then I would make sure it is far enough out from the wall that it has full front access.

If you have a proposed layout many here are happy to critique it.
 
Shimmy said:
If everything is the same depth (+/-), it can share the same 30" working space horizontally. You would not want to have a 18" deep piece of equipment on either side of a panel without a full 30" width in front of the panel. The code now has some exemptions for things like wireway being deeper but I don't remember the precise details. (so on #3, no "dedicated" 30" width per panel)

The code intent for panels is also to make sure there is adequate space for conduit to enter the enclosure (clear on the wall from floor to ceiling). You can put more things in there as long as it does not interfere with a clean installation. But, anything the electrician installs is essentially fair game as long as working clearances are maintained.

Generally, I would try to arrange panels and equipment so there is clean flow and short conduits; going right to left on a wall I might have the panelboard, inverter, PV disconnect, and then battery if there is one. I would stack the solar charge controller and PV disconnect, and if there is enough space above/below the inverter I would put communications electronics and similar accessories. If the "front" of a server rack battery (the clear working space) needs to share the workings pace of the panels and inverters then I would make sure it is far enough out from the wall that it has full front access.

If you have a proposed layout many here are happy to critique it.
Click to expand...
Wireways, etc. are up to 6” “in front” I believe. Supposedly this limit goes away under the latest NEC revision.

”Equipment such as an electrical meter are allowed to protrude into the working space up to a maximum of 6 in. (150 mm)…Within the height requirements of this section, other equipment or support structures, such as concrete pads, associated with the electrical installation and located above or below the electrical equipment shall be permitted to extend not more than 150 mm (6 in.) beyond the front of the electrical equipment.”
 
OK, thank you all, for the detailed replies.

Am adding a backup power system to the existing FLA-based power system. This system, and batteries have been in daily off-grid use for just over 17 years. Have 660 Ah of Server Rack batts as the backup. Plan to bridge these two batt banks together, using a additional AIO inverter to as a load on the server batt, and charge them from the 240 VAC output of the existing inverters (Xantrex SW+ 5548s), and so on.

Had felt that some day, perhaps soon, that some of these FLAs may start to fail, and with long lead times, this could be an issue. But, there is little enough room for the existing system, let alone the gear that is needed to use/support the additional batts ...

Will noodle on this for a while more. Presently there is only the new MN Barcelona SCC on the new wall, and the layout has always felt like it was creating just too many bees in the head.

Thank you all, again, very much! I do understand much in these regs better, now, just lotsa tradeoffs. Luke
 
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