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210.25 (A) branch circuits , more than one occupancy. ‘Loads associated with’

Merry Christmas

Snowbound

Member
Location
Alaska
Occupation
Electrical Contractor
There is a single family home(A) with an apartment(B). The boiler is located in (A) but supplies water to (B). It is fed from a panel in (A) the ’Load’ is in (A) but the ‘or loads associated only with that unit, is problematic. No common areas, single meter. Does hot water running through (B) make it a load associated with both units? Seems unreasonable to bring the breaker outside to the meter to comply with NEC. What might the purpose be that someone in B needs to turn off the boiler but not have access to it? thoughts?
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
My head hurts. This is an accessory apartment much like millions of others. Power, heat and water is supplied by the home it is part of. If there are any problems the renter has to get in touch with the owner. Unless there are local ordinances, I don't see what the problem is.

-Hal
 

Snowbound

Member
Location
Alaska
Occupation
Electrical Contractor
It is an ADU, the Inspector is hung up on “loads associated with“ . since the boiler sends hot water does that mean it’s “Associated” with both?
 

Snowbound

Member
Location
Alaska
Occupation
Electrical Contractor
I am trying to reason it out with him. The best I can think of is if there were two meters and I did a load calculation to size the breakers obviously the boilers “load” would go to the unit with the boiler, not some percentage to the adjacent apartment. I think it’s a vocabulary thing, would be nice to find something example somewhere, a picture….i know it’s wrong.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
It is an ADU, the Inspector is hung up on “loads associated with“ . since the boiler sends hot water does that mean it’s “Associated” with both?
I don't understand. What difference does it make? Is he talking about the electrical load of the boiler and how it should be apportioned to each unit?

-Hal
 

Snowbound

Member
Location
Alaska
Occupation
Electrical Contractor
i don’t understand the motivation of the inspector. he Is taking the words “loads associated with” and applying them to the boiler in that it heats both units , a shared utility, so it is associated with both units thus breaker needs to be assessable by both units. Obviously not right. To argue this nonsense all I can think of is the (Load) is not associated with both units because if I were to calculate the loads of each unit to minimize their respective feeders I would not take some percentage of the boilers load in A and apply it to the service calculation of B, thus this load is (Not) associated with B. That it is sending hot water ,a shared utility, is inconsequential.
is this a valid argument?
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
210.25(A) says: "(A) Dwelling Unit Branch Circuits. Branch circuits in each dwelling unit shall supply only loads within that dwelling unit or loads associated only with that dwelling unit."

So for a branch circuit in dwelling unit A to supply a load, at least one of two things must be true: (1) the load is is within dwelling unit A, or (2) the load is associated only with dwelling unit A, meaning it is not associated with any other dwelling unit.

If (1) is true, then (2) does not need to be true. So if the load is the boiler (it is), and the boiler is within dwelling unit A, it doesn't matter if the boiler is associated with more than one dwelling unit (which it arguably is). (1) is satisfied, and that is enough to satisfy 210.25(A).

Cheers, Wayne
 

Snowbound

Member
Location
Alaska
Occupation
Electrical Contractor
210.25(A) says: "(A) Dwelling Unit Branch Circuits. Branch circuits in each dwelling unit shall supply only loads within that dwelling unit or loads associated only with that dwelling unit."

So for a branch circuit in dwelling unit A to supply a load, at least one of two things must be true: (1) the load is is within dwelling unit A, or (2) the load is associated only with dwelling unit A, meaning it is not associated with any other dwelling unit.

If (1) is true, then (2) does not need to be true. So if the load is the boiler (it is), and the boiler is within dwelling unit A, it doesn't matter if the boiler is associated with more than one dwelling unit (which it arguably is). (1) is satisfied, and that is enough to satisfy 210.25(A).

Cheers, Wayne
 
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