Service and Working Space questions

[olc]

Existing historical building repair & service upgrade (it is an old house but used as museum now):
Existing main disconnect/panelboard is in the basement.

1. Service disconnect (MCB in the panelboard below) - "inside nearest the point of entrance" - Is about 2 feet from the wall close enough?

2. Working space for a new panelboard - in the basement the bottom of the floor joists above is about 6 feet. There is no place on the upper floors where the panelbd can be installed.

 

[DBill64]

There is no actual set distance for what "inside nearest point of entrance" means. 2 feet from the entrance to the building would be more than close enough, but this is in the basement. I would add an external disconnect to make your local firefighters and inspector happy, since even with the new panel install the main disconnect would still end up being in the basement.

Is the new panelboard under 200A? 110.26(A)(3) Exception 2 says that the vertical working space can be less than 6.5 feet if it is less than 200 amps and if it is an existing dwelling unit. But I imagine that was to grandfather in old installs that were made before the working space requirements? So it may not cover a new panelboard install.

(3) Height of Working Space.
The work space shall be clear and extend from the grade, floor, or platform to a height of 2.0 m (61⁄2 ft) or the height of the equipment, whichever is greater. 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.

Exception No. 2:
In existing dwelling units, service equipment or enclosed panelboards that do not exceed 200 amperes shall be permitted in spaces where the height of the working space is less than 2.0 m (61⁄2 ft).

 

[charlie b]

DBill64's post raises an interesting issue to my mind. This facility might have once met the definition of a "dwelling unit." But do the related rules (and exceptions) still apply, since the facility is now a museum?

 

[Master Nater]

There is no actual set distance for what "inside nearest point of entrance" means. 2 feet from the entrance to the building would be more than close enough, but this is in the basement. I would add an external disconnect to make your local firefighters and inspector happy, since even with the new panel install the main disconnect would still end up being in the basement.

Is the new panelboard under 200A? 110.26(A)(3) Exception 2 says that the vertical working space can be less than 6.5 feet if it is less than 200 amps and if it is an existing dwelling unit. But I imagine that was to grandfather in old installs that were made before the working space requirements? So it may not cover a new panelboard install.

(3) Height of Working Space.
The work space shall be clear and extend from the grade, floor, or platform to a height of 2.0 m (61⁄2 ft) or the height of the equipment, whichever is greater. 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.

Exception No. 2:
In existing dwelling units, service equipment or enclosed panelboards that do not exceed 200 amperes shall be permitted in spaces where the height of the working space is less than 2.0 m (61⁄2 ft).

110.26(A)(3)(ex 2) says "In existing dwelling units," ... blah, blah, blah "panelboards that DO NOT EXCEED 200A." it does not say "less than 200a".

so, if it is considered a dwelling unit, he's good to intall new. if not, exception does not apply and he's gotta find somewhere else.

historical or not, a dwelling unit is defined as - "a single unit, providing emplete and independent living facilities for one or more persons, including permanaent provisions for living, sleeping, cooking, and sanitation."

so, if it has a bedroom, a kitchen, and a bathroom, it should apply. but that may be up to the AHJ.

 

[DBill64]

110.26(A)(3)(ex 2) says "In existing dwelling units," ... blah, blah, blah "panelboards that DO NOT EXCEED 200A." it does not say "less than 200a".

Ah good catch. Sometimes reading comprehension is not my strongest trait.

historical or not, a dwelling unit is defined as - "a single unit, providing emplete and independent living facilities for one or more persons, including permanaent provisions for living, sleeping, cooking, and sanitation."

so, if it has a bedroom, a kitchen, and a bathroom, it should apply. but that may be up to the AHJ.

And yah that's my main question. I imagine it still has all the utilities required to be a livable home (we know it has power so: water, sewer/septic, etc.) and it was used as a residence before so it must meet the requirements of a dwelling. But perhaps since it is now being used as a museum that might change its local zoning? Which might change local code requirements for it? But as you said: that would be up to the AHJ.

 

[Master Nater]

Ah good catch. Sometimes reading comprehension is not my strongest trait.


And yah that's my main question. I imagine it still has all the utilities required to be a livable home (we know it has power so: water, sewer/septic, etc.) and it was used as a residence before so it must meet the requirements of a dwelling. But perhaps since it is now being used as a museum that might change its local zoning? Which might change local code requirements for it? But as you said: that would be up to the AHJ.

i only caught it, because i was asked about it a couple of weeks ago.

maybe he can work the angle, that the panel should be allowed, because as a museum, it was "historically acceptable"??? hahaha!

(seems like a lot of regulations just to see whether it's ok to have 6" of less headroom for a panel)