A question regarding NEC 210.25. A commercial building with two apartments above. The apartments are separately metered. The common loads are fed from a ?house panel? that is fed from the panel servicing the commercial space. All the building is under one owner. Overcurrent devices will be accessible. Is this a legal installation? The commentary following 210.25 makes accessibility of overcurrent devices the main concern. Does the NEC 210.25 statement ?not supplied from equipment? mean not the same panel or not the same service?
Nec 210.25
- Thread starter wyboy
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What code cycle are you working under?
IMHO the term "Shall not be supplied from equipment that supplies an individual dwelling unit" would mean you need a separate panelboard to supply house loads and not necessarily a separate service.
Chris
IMHO the term "Shall not be supplied from equipment that supplies an individual dwelling unit" would mean you need a separate panelboard to supply house loads and not necessarily a separate service.
Chris
- Location
- Lockport, IL
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- Semi-Retired Electrical Engineer
If a panel has a branch circuit feeding outlets in one of the dwelling units, then that panel cannot also have a branch circuit feeding a common house load. But a service panel that supplies a panel inside one unit can also supply a separate panel that serves house loads. What you described sounds fine to me.
Hendrix
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So, what you're saying is that a "house panel" does not need to be metered spearately?
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- Lockport, IL
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The utility might care where the meters are installed. The NEC doesn't. The NEC requirement is that a panel serving loads within a dwelling unit cannot also serve house loads.
charlieb, under the '08 change (adding the word "tenant space") does that not almost mandate a "house panel" to serve common loads ?
For example, in the situation from the OP, under the '08 Code it appears to me that the "commercial space" panel could not serve the "common areas". Am I incorrect ?
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- Lockport, IL
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- Semi-Retired Electrical Engineer
I may have misinterpreted the description. I had thought the owner owned the commercial space, and was renting out the second floor to others. Now I see there is nothing in the original description that says this. So let me ask if this is the situation:
- Meter #1 supplies Panel #1 which serves Dwelling Unit #1.
- Meter #2 supplies Panel #2 which serves Dwelling Unit #2.
- Meter #3 supplies Panel #3 which serves the commercial unit and also has breakers serving house loads.
Hendrix
Senior Member
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- New England
That was my take on the post. Thanks for the clairification.
I believe this is one of those requirements that don't really say what you think it does... at least, not exactly.
Technically, one panel could supply all the branch circuit loads in the OP's scenario... that is, if the service was one meter instead of split through 3, and the panelboard was entirely outside or located in a common area.
The requirement is essentially that a branch circuit does not serve more than one occupancy unit, or an occupancy unit and a common area. However, there is no explicit mention on where the circuit must originate. Yes, it seems that it states the branch circuit must originate within the occupancy unit served... but that is simply not true. Branch circuits may originate outside the occupancy unit served so long as they do not pass through another occupancy unit en route to another. It is entirely okay to route branch circuits serving an individual occupancy unit from and through common areas.
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Realizing that the Handbook is not gospel, here it what it says:
(B) Common Area Branch Circuits. Branch circuits required for the purpose of lighting, central alarm, signal, communications, or other needs for public or common areas of a two-family dwelling, a multifamily dwelling, or a multi-occupancy building shall not be supplied from equipment that supplies an individual dwelling unit or tenant space.
Not only does 210.25 prohibit branch circuits from feeding more than one dwelling unit, it also prohibits the sharing of systems, equipment, or common lighting if that equipment is fed from any of the dwelling units. In addition, common area circuits in other than dwelling occupancies are now subject to this requirement, and ?house load? branch circuits must be supplied from equipment that does not directly supply branch circuits for an individual occupancy or tenant space. The systems, equipment, or lighting for public or common areas is required to be supplied from a separate ?house load? panelboard. This requirement permits access to the branch-circuit disconnecting means without the need to enter the space of any tenants. The requirement also prevents a tenant from turning off important circuits that may affect other tenants.
(emphasis mine)
That appears to disagree with what I think you are stating.
(B) Common Area Branch Circuits. Branch circuits required for the purpose of lighting, central alarm, signal, communications, or other needs for public or common areas of a two-family dwelling, a multifamily dwelling, or a multi-occupancy building shall not be supplied from equipment that supplies an individual dwelling unit or tenant space.
Not only does 210.25 prohibit branch circuits from feeding more than one dwelling unit, it also prohibits the sharing of systems, equipment, or common lighting if that equipment is fed from any of the dwelling units. In addition, common area circuits in other than dwelling occupancies are now subject to this requirement, and ?house load? branch circuits must be supplied from equipment that does not directly supply branch circuits for an individual occupancy or tenant space. The systems, equipment, or lighting for public or common areas is required to be supplied from a separate ?house load? panelboard. This requirement permits access to the branch-circuit disconnecting means without the need to enter the space of any tenants. The requirement also prevents a tenant from turning off important circuits that may affect other tenants.
(emphasis mine)
That appears to disagree with what I think you are stating.
Perhaps the intent is more aligned to your belief. I am just going by the words as written in the code.
First, you have to eliminate any preconceived notions to see the difference. I broke out the commentary to point out where the difference is... that being the word "individual". If equipment serves an "individual" dwelling unit or tenant space, then it logically does not serve any other space. If it serves more than one "individual" dwelling unit or tenant space, then it obviously does not supply only an "individual" dwelling unit or tenant space :roll:
The key in the requirement is that once a branch circuit is in a dwelling unit or tenant space, it cannot supply another space. Also please note the requirement is regarding the branch circuit, not just the outlet or outlets of the branch circuit. However, I invite you to show me in the requirements where it states the branch circuit cannot originate in equipment outside the individual dwelling unit or tenant space. In other words, the requirement does not state, as I read it, the branch circuit cannot also be outside or in a common area... just that it cannot supply any loads in these other areas.
Once again, the commentary appears to be based intent and likely the preconceived notion the panelboard supplying branch circuits is located within the dwelling unit or tenant space supplied. Therefore, you have to ask yourself the question, what if the panelboard is not located within the dwelling unit or tenant space that it supplies...???
PS: Would you please use SIZE=2 or larger text (or at least include plenty of white space)? SIZE=1 text appears very small in my browser (on my desktop monitor), making it difficult to read.
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I think your comment is finally sinking thru my thick skull.
If I may: I think you are telling me that a panel that feeds and individual tenant space only (dwelling unit or other) can not supply "common area feeds", whereas a panel(s) that feeds an entire premises (all dwelling units, tenant spaces,etc) can feed the common areas also.
Is that correct ?
(comment in ps. noted. I was attempting to keep the post "small" and it is easy to read on my monitor, but see where that might not be true in all cases... practice deleted..thanks)
If I may: I think you are telling me that a panel that feeds and individual tenant space only (dwelling unit or other) can not supply "common area feeds", whereas a panel(s) that feeds an entire premises (all dwelling units, tenant spaces,etc) can feed the common areas also.
Is that correct ?
(comment in ps. noted. I was attempting to keep the post "small" and it is easy to read on my monitor, but see where that might not be true in all cases... practice deleted..thanks)
Well, sort of correct. You first have to establish the location of the panelboard. If the panelboard is within an occupancy unit (which covers both types
), it cannot supply branch circuits other than those pertaining to the unit it is located in.If the panelboard is not located within an occupancy unit?that is, outside or in a public or common area?it can supply branch circuits to the entire premises. However, in this case, a branch circuit can only enter one occupancy unit, and cannot supply any common loads.
LarryFine
Master Electrician Electric Contractor Richmond VA
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Pierre C Belarge
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I need a:
Larry,
I have been reading your posts, and yes, I agree you could use a secretary.
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