Article 230.40 except. 2 and 230.71

[Dennis Alwon]

I listed the articles below that I feel are pertinent to the question.

Lets say we have a 1000 amp service which consists of 5- 200 amp ML enclosures. In each enclosure I have a 150 amp breaker that is used as the service disconnecting means-- total of 5. Now I want to add another overcurrent protective device in one of the enclosure to meet the 6 handle rule. Where in 230.71 does it allow me to do this. It seems that exception 2 is left out of the article and this would not be compliant even though there are only 6 throws for the building. Can someone agree or not and maybe explain why exception 2 was left out

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. 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.

230.71 Maximum Number of Disconnects.
(A) General. The service disconnecting means for each
service permitted by 230.2, or for each set of serviceentrance
conductors permitted by 230.40, Exception No. 1,
3, 4, or 5, shall consist of not more than six switches or sets
of circuit breakers, or a combination of not more than six
switches and sets of circuit breakers, mounted in a single
enclosure, in a group of separate enclosures, or in or on a
switchboard or in switchgear. There shall be not more than
six sets of disconnects per service grouped in any one location.

 

[mwm1752]

Seems to me if you included exception 2# in 230.71 you would only be repeating what (A) is intending for 1,3,4,or,5 -- Bottom line both call out max 6 disconnects.

 

[Dennis Alwon]

Yes, six disconnects are compliant but since 230.71 excludes except #2 then you cannot have 2 disconnects in one enclosure.

 

[david]

Yes, six disconnects are compliant but since 230.71 excludes except #2 then you cannot have 2 disconnects in one enclosure.

doesn't exception 2 state that up to six service disconnects are in separate enclosures grouped together and supplying separate loads.

not sure if the disconnects are in the same enclosure they would qualify as supplying separate loads.

separate loads have been debated here in the past.

ether way nothing says the rules cannot be mixed and matched as long as the six disconnect from the utility happens

 

[Dennis Alwon]

doesn't exception 2 state that up to six service disconnects are in separate enclosures grouped together and supplying separate loads.

not sure if the disconnects are in the same enclosure they would qualify as supplying separate loads.

separate loads have been debated here in the past.

ether way nothing says the rules cannot be mixed and matched as long as the six disconnect from the utility happens

Correct, except 2 allows them in separate loads but why are we not allowed to put 2 disconnects for different loads in one enclosure and count that. We can have 6 disconnects in one enclosure and we can have 6 disconnects in 6 enclosures but it doesn't look like we can have a combination of the two. I never noticed this and I am curious as to why

 

[wwhitney]

. . . mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard or in switchgear. . .

I don't read "a group of separate enclosures" to mean one enclosure per "switch". I think the language allows two "switches" in one enclosure, or any arrangement of up to six switches spread over up to six enclosures.

As to why 230.71(A) doesn't reference 230.40 Exception 2, my take is the following: 230.71(A) allows six "switches" per "set of service-entrance conductors" allowed by the 230.40 exceptions (other than 2). So if you have two sets of service entrance conductors because of two different occupancies under 230.40 Exception 1, then you could have twelve total "switches", six per set.

But 230.40 exception 2 allows multiple sets of service entrance conductors just so that you can spread your up to six "switches" among different enclosures. If it were again referenced in 230.71(A), then you could have six enclosures, six sets of service conductors, and six "switches" per enclosure/set of service entrance conductors, and 36 "switches" total. That's not the intent of the 230.40 exception 2 allowance, so it is excluded from 230.71(A).

Cheers, Wayne

 

[Dennis Alwon]

I like what you said but let me ask you this. Where in 230.71, which is about Number of disconnects, does it allow you to have more than 2 disconnects where you have a 400 amp service with 2- 200 amp panels. IMO , you cannot have 2- main lug panels with say 3 breakers in each one to serve as the service disconnect.

I see the nec allowing either 6 disconnects in one enclosure or 6 disconnects in 6 enclosures if you are using except. 2. For some reason you cannot use a combination of the two methods

Remember 230.40 is for service conductors and 230.71 is the rule for the disconnects

 

[wwhitney]

Where in 230.71, which is about Number of disconnects, does it allow you to have more than 2 disconnects where you have a 400 amp service with 2- 200 amp panels. IMO , you cannot have 2- main lug panels with say 3 breakers in each one to serve as the service disconnect.

What language do you see as prohibiting this? I already mentioned that I don't read "in a group of separate enclosures" as meaning one enclosure per switch; as I see it that language allows the arrangement you mention. Is there other language in 230.71 that you read as prohibiting this?

Cheers, Wayne

 

[Dennis Alwon]

What language do you see as prohibiting this? I already mentioned that I don't read "in a group of separate enclosures" as meaning one enclosure per switch; as I see it that language allows the arrangement you mention. Is there other language in 230.71 that you read as prohibiting this?

Cheers, Wayne

I think I see where you are coming from and before you posted I had come to the same conclusion but a bit differently.

Apparently this has been quite the discussion in our area lately and many don't see it as you do. I think your point about why exception 2 is not listed is the clincher for me and I appreciate your response. I think you are spot on this. Thanks

 

[david]

I like what you said but let me ask you this. Where in 230.71, which is about Number of disconnects, does it allow you to have more than 2 disconnects where you have a 400 amp service with 2- 200 amp panels. IMO , you cannot have 2- main lug panels with say 3 breakers in each one to serve as the service disconnect.

I see the nec allowing either 6 disconnects in one enclosure or 6 disconnects in 6 enclosures if you are using except. 2. For some reason you cannot use a combination of the two methods

Remember 230.40 is for service conductors and 230.71 is the rule for the disconnects

230.71 Maximum Number of Disconnects.

“(A) General. The service disconnecting means for each service permitted by 230.2, or for each set of service-entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5, shall consist of not more than six switches or sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard.”

The quoted part of 230.71 is silent in regards to 230.40 ex. 2. Yet we know the subject of 230.71 is maximum number of disconnects. I however do not believe I can conclude that the last sentence in section 230.71 can also be excluded from application to 230.40 ex. 2.

230.71 Maximum Number of Disconnects.
“There shall be not more than six sets of disconnects per service grouped in any one location.”

230.40 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 or lateral, one set of service-entrance conductors shall be permitted to supply each or several such service equipment enclosures.

If 230.40 Exception No. 2: does not mean the service entrance conductors and the up to six disconnecting means are in separate enclosures than the break down in 230.70 excluding exception 2 in the paragraph does not make any sence.

 

[david]

Nothing in 230.40 addresses how many service disconnects are allowed in a service disconnecting means enclosure.

The section is an allowance to supply up to six separate enclosures grouped together with more than one service entrance

 

[Dennis Alwon]

Nothing in 230.40 addresses how many service disconnects are allowed in a service disconnecting means enclosure.

The section is an allowance to supply up to six separate enclosures grouped together with more than one service entrance

Correct 230.40 is only about service entrance conductors bt inadvertently brings in the 6 handle rule.

David, I apologize but I am not sure where you stand on this.. It sounds like you agree that more than one disco can be used in an enclosure when there is more than one

 

[david]

Correct 230.40 is only about service entrance conductors bt inadvertently brings in the 6 handle rule.

David, I apologize but I am not sure where you stand on this.. It sounds like you agree that more than one disco can be used in an enclosure when there is more than one

I do not see the code prohibiting more than one.

Although 230.40 only states the allowance for separate service entrances is for up to six separate enclosures with disconnecting means it does not address if one of those enclosures could be a split buss panel for instance , very common here in older installations. As long as the six disconnects of the electrical utility is not exceeded.

This was a common violation with split buss panels in two family dwellings grouped together in a common basement location with two additional (off peak metered) 60 amp service entrances to 30 amp hot water tanks

 

[Dennis Alwon]

I do not see the code prohibiting more than one.

Although 230.40 only states the allowance for separate service entrances is for up to six separate enclosures with disconnecting means it does not address if one of those enclosures could be a split buss panel for instance , very common here in older installations. As long as the six disconnects of the electrical utility is not exceeded.

This was a common violation with split buss panels in two family dwellings grouped together in a common basement location with two additional (off peak metered) 60 amp service entrances to 30 amp hot water tanks

I thought that is what you were saying. I admit it had me for awhile and in fact has some of our local inspectors unsure about it also so that is why I brought it up. Last night as I drove to get pizza is when I realized what I was missing. WWhitney got me going on that thought. Thanks all