Grouping of Service Disconnects

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mwm1752

Senior Member
Location
Aspen, Colo
Does a two family dwelling meet the exception 1(building with more than one occupancy ) for 230.40 so that the services do not have to be grouped?

230.40 Number of Service-Entrance Conductor Sets
Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral shall supply only one set of service-entrance conductors.
Exception No. 1: A building with more than one occupancy shall be permitted to have one set of service-entrance conductors for each service, as defined in 230.2, run to each occupancy or group of occupancies. If the number of service disconnect locations for any given classification of service does not exceed six, the requirements of 230.2(E) shall apply at each location. If the number of service disconnect locations exceeds six for any given supply classification, all service disconnect locations for all supply characteristics, together with any branch circuit or feeder supply sources, if applicable, shall be clearly described using suitable graphics or text, or both, on one or more plaques located in an approved, readily accessible location(s) on the building or structure served and as near as practicable to the point(s) of attachment or entry(ies) for each service drop or service lateral, and for each set of overhead or underground service conductors.
 

david

Senior Member
Location
Pennsylvania
Does a two family dwelling meet the exception 1(building with more than one occupancy ) for 230.40 so that the services do not have to be grouped?

230.40 Number of Service-Entrance Conductor Sets
Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral shall supply only one set of service-entrance conductors.
Exception No. 1: A building with more than one occupancy shall be permitted to have one set of service-entrance conductors for each service, as defined in 230.2, run to each occupancy or group of occupancies. If the number of service disconnect locations for any given classification of service does not exceed six, the requirements of 230.2(E) shall apply at each location. If the number of service disconnect locations exceeds six for any given supply classification, all service disconnect locations for all supply characteristics, together with any branch circuit or feeder supply sources, if applicable, shall be clearly described using suitable graphics or text, or both, on one or more plaques located in an approved, readily accessible location(s) on the building or structure served and as near as practicable to the point(s) of attachment or entry(ies) for each service drop or service lateral, and for each set of overhead or underground service conductors.

You asked do the services have to be grouped, but by the reference you gave I assume you are asking do the service disconnects have to be grouped.

I would say yes the exception applies. However I see much confusion when these rules are applied.

I always tell guys as a point of reference to understanding these rules go to the service disconnect location . If you open all the service disconnects associated with/ in that occupancy, at that location are all the branch circuits, feeders and service entrance conductors de-energized , if not then something is wrong.

So many times the service disconnects are open at a location and there is a live feeder passing through.
 

mwm1752

Senior Member
Location
Aspen, Colo
David - If a two family dwelling is not interpreted as a(building with more than one occupancy ) your service disconnects for the structure shall be grouped. My question lies on if the concencus believes a two family dwelling is a building with more than one occupancy.
Occupancy can be defined as a type or use of building ( residential & commercial)and can also be defined as a quanity of occupants(2 residential units).
 

david

Senior Member
Location
Pennsylvania
Compliant?

Before I could answer I would need to know how many times this dual occupancy single building is supplied by the utility.

Or I would have to know is by your building department s classification is what your showing two separate buildings (fire wall separation)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
David - If a two family dwelling is not interpreted as a(building with more than one occupancy ) your service disconnects for the structure shall be grouped. My question lies on if the concencus believes a two family dwelling is a building with more than one occupancy.
Occupancy can be defined as a type or use of building ( residential & commercial)and can also be defined as a quanity of occupants(2 residential units).
For the purposes of this section, the fact that each dwelling unit has its own meter, makes them separate occupancies.
 

david

Senior Member
Location
Pennsylvania
Does a two family dwelling meet the exception 1(building with more than one occupancy ) for 230.40 so that the "services" do not have to be grouped?[/I]

with out knowing if the meters are ganged at one location and all the diagram is showing is the service disconnect locations.

Or is the structure being supplied to separate meter locations and that is what is being diagramed.

The second question asked is the diagram compliant?

I'm am still not sure if what is being asked ,can this building ( or two buildings) be supplied by two services,

or can a duel occupancy building have two service entrances with the service disconnect in two different locations


Yes separate occupancies can have an outside service entrance from one service drop or service lateral run to each occupancy in a multi occupancy building
 

david

Senior Member
Location
Pennsylvania
For the purposes of this section, the fact that each dwelling unit has its own meter, makes them separate occupancies.

Don I would agree with that in principle, but we have several what we call grandmother suits.

An addition is built onto a house for mom or dad who still want to pay their way. Two entirely separate dwelling units under one roof, some even have a hotel passage style door between the two, Others an open floor plan each section with its own kitchen, bathroom the whole works.

I do agree except for rare exceptions .
 
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For the purposes of this section, the fact that each dwelling unit has its own meter, makes them separate occupancies.

Don, I am not sure I agree that you can make that generalization. Here is my take on it. The NEC doesnt define "occupancy" so I think an inspector could say something like, "show me a letter from the building dept saying this is two occupancies." Then it would be up to the building dept and whatever codes, standards, and fire ratings they use/require to decide. In practice I know it can be more lax than that. In upstate NY for example it is very common to have a two or three unit apartment building with a set of service entrance conductors run to each unit. However I have also run across this situation in other places where it is more strict and defined and what appeared to be two occupancies were not.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Don, I am not sure I agree that you can make that generalization. Here is my take on it. The NEC doesnt define "occupancy" so I think an inspector could say something like, "show me a letter from the building dept saying this is two occupancies." Then it would be up to the building dept and whatever codes, standards, and fire ratings they use/require to decide. In practice I know it can be more lax than that. In upstate NY for example it is very common to have a two or three unit apartment building with a set of service entrance conductors run to each unit. However I have also run across this situation in other places where it is more strict and defined and what appeared to be two occupancies were not.
This is not a building code use of the term occupancy. The only way you can have more than one meter for a structure is if there is more than one occupancy or if you have a single occupancy that requires more than one type of electrical supply. For the purposes of this section, multiple meters equals multiple occupancies.
 

mwm1752

Senior Member
Location
Aspen, Colo
with out knowing if the meters are ganged at one location and all the diagram is showing is the service disconnect locations.

Or is the structure being supplied to separate meter locations and that is what is being diagramed.

The second question asked is the diagram compliant?

I'm am still not sure if what is being asked ,can this building ( or two buildings) be supplied by two services,

or can a duel occupancy building have two service entrances with the service disconnect in two different locations


Yes separate occupancies can have an outside service entrance from one service drop or service lateral run to each occupancy in a multi occupancy building

David. while I appreciate your diligence the drawing was simple as the question asked - Two family dwelling - the disconnect is a meter/main combo - only one transformer feeds the building and service complies with 230.2 & 230.40 , Exception No. 2 -- as the drawing shows only one foundation for this structure -- the structure does not readily fit within the parameters of 230.2 (A-D) for more than one service. -- there is dwelling separation requirements -- If you want to state the two family dwelling is a multi occupancy building please be clear -- and is the meter/main locations compliant with the NEC as described above ?
Once again My question lies on if the concencus believes a two family dwelling is a building with more than one occupancy.
Occupancy can be defined as a type or use of building ( residential & commercial)and can also be defined as a quanity of occupants(2 residential units).
 

iwire

Moderator
Staff member
Location
Massachusetts
This is not a building code use of the term occupancy. The only way you can have more than one meter for a structure is if there is more than one occupancy or if you have a single occupancy that requires more than one type of electrical supply. For the purposes of this section, multiple meters equals multiple occupancies.

Are you saying if I have say, a one owner stand alone commercial garage with a three phase service and and single phase service I now have two occupancies?
 

mwm1752

Senior Member
Location
Aspen, Colo
This is not a building code use of the term occupancy. The only way you can have more than one meter for a structure is if there is more than one occupancy or if you have a single occupancy that requires more than one type of electrical supply. For the purposes of this section, multiple meters equals multiple occupancies.

Don,
Where are the requirements to have multiple meters for multi- occupancy buildings -- A landlord may option to include a standard utility rate as part of rent - The question would come under ownership of the building or sections of the building.
 

david

Senior Member
Location
Pennsylvania
David. while I appreciate your diligence the drawing was simple as the question asked - Two family dwelling - the disconnect is a meter/main combo - only one transformer feeds the building and service complies with 230.2 & 230.40 , Exception No. 2 -- as the drawing shows only one foundation for this structure -- the structure does not readily fit within the parameters of 230.2 (A-D) for more than one service. -- there is dwelling separation requirements -- If you want to state the two family dwelling is a multi occupancy building please be clear -- and is the meter/main locations compliant with the NEC as described above ?
Once again My question lies on if the concencus believes a two family dwelling is a building with more than one occupancy.
Occupancy can be defined as a type or use of building ( residential & commercial)and can also be defined as a quanity of occupants(2 residential units).

Respectfully I have to disagree that the building is supplied by only one service. In accordance with 230.2 referencing 230.40 exception # 2.

You state that it is supplied by the same utility transformer and I really don?t think that has any significance in making the determination; the building is supplied by only one service.

The two sections taken together basically say to consider it one service, the lateral connections to the Utility (transformer), the laterals have to be no smaller than 1/0 run to the same location and the separate service disconnects for those utility connections have to be grouped together.

Since your service disconnects are not grouped together you have more than one service supplying this structure.

If you are correct that the building department has determined this to be only one building I find the diagram to not be in compliance with 230.3
 
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david

Senior Member
Location
Pennsylvania
Change the lateral to supply a two ganged meter enclosure and we can determine the two occupancies can have a service entrance run to service equipment for each occupant separately
 

mwm1752

Senior Member
Location
Aspen, Colo
David, Certainly, our conversation is enlightening and appreciated;

230.40 Number of Service-Entrance Conductor Sets
Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral shall supply only one set of service-entrance conductors. Charging Statement that is code
Exception No. 2: Where two to six service disconnecting means in separate enclosures are grouped at one location and supply separate loads from one service drop, set of overhead service conductors, set of underground service conductors, or service lateral, one set of service-entrance conductors shall be permitted to supply each or several such service equipment enclosures. Certainly the drawing does not show a grouped disconnecting means at one location. All other circumstances apply.

Exception No. 1: A building with more than one occupancy shall be permitted to have one set of service-entrance conductors for each service, as defined in 230.2
, run to each occupancy or group of occupancies. If the number of service disconnect locations for any given classification of service does not exceed six, the requirements of 230.2(E) shall apply at each location. If the number of service disconnect locations exceeds six for any given supply classification, all service disconnect locations for all supply characteristics, together with any branch circuit or feeder supply sources, if applicable, shall be clearly described using suitable graphics or text, or both, on one or more plaques located in an approved, readily accessible location(s) on the building or structure served and as near as practicable to the point(s) of attachment or entry(ies) for each service drop or service lateral, and for each set of overhead or underground service conductors.Per the inquirey is a two family dwelling considered "A building with more than one occupancy" so that "one set of service-entrance conductors for each service, as defined in 230.2, run to each occupancy or group of occupancies" would allow the locations for the disconnecting means the structure not to be grouped.
 

david

Senior Member
Location
Pennsylvania
David, Certainly, our conversation is enlightening and appreciated;

230.40 Number of Service-Entrance Conductor Sets
Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral shall supply only one set of service-entrance conductors. Charging Statement that is code
Exception No. 2: Where two to six service disconnecting means in separate enclosures are grouped at one location and supply separate loads from one service drop, set of overhead service conductors, set of underground service conductors, or service lateral, one set of service-entrance conductors shall be permitted to supply each or several such service equipment enclosures. Certainly the drawing does not show a grouped disconnecting means at one location. All other circumstances apply.

Exception No. 1: A building with more than one occupancy shall be permitted to have one set of service-entrance conductors for each service, as defined in 230.2
, run to each occupancy or group of occupancies. If the number of service disconnect locations for any given classification of service does not exceed six, the requirements of 230.2(E) shall apply at each location. If the number of service disconnect locations exceeds six for any given supply classification, all service disconnect locations for all supply characteristics, together with any branch circuit or feeder supply sources, if applicable, shall be clearly described using suitable graphics or text, or both, on one or more plaques located in an approved, readily accessible location(s) on the building or structure served and as near as practicable to the point(s) of attachment or entry(ies) for each service drop or service lateral, and for each set of overhead or underground service conductors.Per the inquirey is a two family dwelling considered "A building with more than one occupancy" so that "one set of service-entrance conductors for each service, as defined in 230.2, run to each occupancy or group of occupancies" would allow the locations for the disconnecting means the structure not to be grouped.

First you have to get past the threshold of one service 230.2

We cannot move past the service requirements and start talking about the service entrance requirements until the service requirements are met.

How does the single structure make it past the service threshold being supplied by two separate utility connections?

I am not sure how I am not answering your question the building as you have presented it is not in compliance with 230.2
 

david

Senior Member
Location
Pennsylvania
When you have a service in compliance you can move on to the service entrance requirements or allowances.

A two family dwelling is considered a building with more than one occupancy in applying these rules .

Yes each occupancy can have one set of service entrances as allowed by 230.2 run to no more than six service disconnect for each type of service allowed.

No the diagram with the information presented is not in compliance with 230.2
 

mwm1752

Senior Member
Location
Aspen, Colo
First you have to get past the threshold of one service 230.2 -- exception #1 refers to 230.2

We cannot move past the service requirements and start talking about the service entrance requirements until the service requirements are met. -- Exception #1 does not require 230.(A-D) to be approved.

How does the single structure make it past the service threshold being supplied by two separate utility connections? -- Exception #1 allows this.

I am not sure how I am not answering your question the building as you have presented it is not in compliance with 230.2
-- If building does not set within the parmeters of exeption 1# we are and have been in total agreement.

 

david

Senior Member
Location
Pennsylvania
-- If building does not set within the parmeters of exeption 1# we are and have been in total agreement.


I guess we are on different pages to 230.40 exception 1 applying to this at all.

IMO 230.40 exception 1 states a building with more than one occupancy, we meet that.
Then there is an allowance for one service entrance (multiple Service Entrances) referring you back to 230.2 for each type of service allowed to supply the building.

If there is only one type of service (one Service) allowed to supply the building, than 230.40 exception 1 Is not applicable to the occupants since it hasn?t been established that two services are allowed to supply the building. since the service disconnects are not grouped and the service lateral is to two different locations

I hope we are in agreement I am not sure.

The only way that I see a single building with two occupants being supplied by a 240/120 single phase service with all the supply characteristics to the two occupants being the same, is if there is just one service lateral or one service drop (2008 terms ) utility supply to this building.

I do not think this is in compliance with 230.40 exception 2 because the building has two different service equipment locations

And not in compliance with 230.40 exception 1 because the service entrance allowances only address service entrance from two different services allowed by 230.2

having two occupancy is given
 
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