Service Disconnecting Means

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jap

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I dont know if my original topic posted so i will try again.

Some AHJ in our area consider the Individual Tennant breakers in a group metering system as as a seperate service and allow as many as needed to feed the load without a main disconnecting means in the Metering Tap Box. I have seen group metering with a lot more than
6 meters and tennant breakers without a Main Disconnecting means in the tap box of the group metering.They consider each individual tennant breaker
a new service. I disagree. In my mind if you have more than 6 Tennant breakers in a group metering system, you should be required to have a Main disconnecting Means in the Tap Box feeding the group metering. I consider the service entrance conductors the Wiring from the utility Xfmr to the Group Metering. Not the wiring from the Tennant Breaker to Load.
Who is correct?
 
230.71 permits each set of service entrance conductors to have up to six means of disconnect. There is no requirement for a main when you have more than six sets of service entrance conductors. Exception #1 to 230.40 permits a single service drop or lateral to supply multiple sets of service entrance conductors for buildings that have multiple occupancies. Each apartment is an occupancy.
Don
 
don_resqcapt19 said:
230.71 permits each set of service entrance conductors to have up to six means of disconnect. There is no requirement for a main when you have more than six sets of service entrance conductors. Exception #1 to 230.40 permits a single service drop or lateral to supply multiple sets of service entrance conductors for buildings that have multiple occupancies. Each apartment is an occupancy.
Don
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Thank You. Very clearly stated. :smile:
 
Humm, so you are saying that 9 apartments in the same building with 9 handles on the outside of one building with one service drop is allowed because there are nine occupancies?

Making sure I understand your point. It's new thinking for me.

Jeremy
 
Humm, so you are saying that 9 apartments in the same building with 9 handles on the outside of one building with one service drop is allowed because there are nine occupancies?
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That is exactly what I am saying.
Don
 
jerm said:
Humm, so you are saying that 9 apartments in the same building with 9 handles on the outside of one building with one service drop is allowed because there are nine occupancies?
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This is assuming one set of service conductors for each occupancy and that set of service conductors is fed from a service drop or lateral. :smile:

jerm said:
Making sure I understand your point. It's new thinking for me.

Jeremy
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Ok, Exception 1 is new to '05- we're still under '02 around here, and I don't ever remember that exception being brought up in any c ed classes for discussion...

It will be interesting to see how our AHJ interprets the new exception in light of 230.2 (which it references), when that time comes.

Jeremy
 
New to me, too.

What if there was one set of service conductors in the drop, and then they were split out to 9 disconnects from the gutter. Still legal?
 
What if there was one set of service conductors in the drop, and then they were split out to 9 disconnects from the gutter. Still legal?
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Yes, each set of service entrance conductors is permitted to have up to 6 disconnects.
Don
 
I thought this would be worth reading


4-44 Log #3262 NEC-P04 Final Action: Reject
(230.40 Exception No. 1 and 230.71(A))
______________________________________________________________
Submitter: Eugene E. Morgan, Clakamas County, Building Codes Divison
Recommendation: Revise text to read as follows:
230.40 Number of service-Entrance Conductor Sets. Each service drop or
lateral shall supply only one set of service-entrance conductors.
Exception No.1: A building 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.
(Delete Exception No.1 and re-number Exceptions 2, 3, 4 and 5 to
Exceptions.......
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​



Substantiation: Exception No.1 to 230.40 is the source of considerable
misunderstanding for installers as well as inspectors. It is in apparent conflict
with 230.70(A)(1) Readily Accessible Location, and with 230.72(A)
Grouping of Disconnects. It is also in apparent conflict with the basic safety
premise of 230.71(A) Maximum Number of Disconnects.
When taken literally, 230.40 Exception No. 1 would seem to allow an
unlimited number of disconnects in an unspecified number of tenant spaces, as
long as there were no more than six at any one location. There is no mention of
area separation requirements that are essential to prevent the spread of fire and
provide for the safety of fire fighters or rescue personnel. In the event of a fire,
earthquake or other disaster, rescue personnel would be severely hampered by
working against energized service, feeder, and branch circuit conductors that
could not be readily disconnected at a common location in such an emergency........
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I cut it down ,. but I think you get his point...


Panel Meeting Action: Reject
Panel Statement: This particular exception has been in the NEC since at
least the 1946 NEC where Section 1807 permitted, by special permission,
more than one set of service drop in a multi-occupancy building where there
was no available space for service equipment accessible to all occupants.
This exception permitted the occupant to have access to their own service
disconnecting means. Section 1837 required a multiple occupancy building
having individual occupancies above the second floor to have the service
equipment grouped in a common accessible location and to consist of not
more than six switches or circuit breakers. However, any multiple occupancy
building that did not have any individual occupancy above the second floor
could have the service conductors run to each occupancy and have up to six
switches or circuit breakers at that location.
Since this rule has existed since the early 1940s without a major change to
the intent, there does not seem to be a compelling reason to change this section
of the Code and there was no technical substantiation given in the proposal to
provide a reason to delete this rule. The submitter did not provide any specific
examples of problems that have occurred where service entrance conductors
have been installed in accordance with the current permissive requirements in
this section.
Exception 1 to 230.40 is a necessary and commonly used allowance for
supplying power in multiple occupancy buildings. The building is still only
permitted to have one service riser or lateral that would allow the power to be
removed from all occupancies when necessary by the disconnection of the riser
or lateral conductors.
Number Eligible to Vote: 10
Ballot Results: Affirmative: 10
______________________________________________________________
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​

 
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don_resqcapt19 said:
230.71 permits each set of service entrance conductors to have up to six means of disconnect. There is no requirement for a main when you have more than six sets of service entrance conductors. Exception #1 to 230.40 permits a single service drop or lateral to supply multiple sets of service entrance conductors for buildings that have multiple occupancies. Each apartment is an occupancy.
Don
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Don
A while back the rule was interpreted as requiring a main switch for each set of 6 apt panels regardless of the number of breakers in the panel. I believe the interpretation now is that you can exceed the 6 sets of service entrance conductors as long as each apt panel does not exceed 6 breakers. Does this agree with what you posted?
 
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I would check local rules ,.. this is from the Mass. State Elec. Code , as you can see it is quite a bit more restrictive than the NEC.

Bob if you have the Hanbook check out page 137 exhibit 230.13 , there are 16 disconnects on one service , and it could have been 24 .


This is a link to a question and answer article question 3 may be worth the read

http://www.iaei.org/subscriber/foc/cmp4.htm

230.40 Amend Exception No. 1 to read:

Exception No. 1: By special permission, where there is no available space for service equipment accessible to all the occupants, buildings with more than one occupancy shall be permitted to have one set of service entrance conductors run to each occupancy or to a group of occupancies.
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I'm curious about the lack of need for a main disco when there are more than six sets of service conductors. What gives? Why would it be that if I tap the same service lateral 5 times, feeding 5 sets of 6 meters, I need a main disconnect....but if I add one more set of service conductors, I no longer need a main? Odd.
 
bcorbin said:
Why would it be that if I tap the same service lateral 5 times, feeding 5 sets of 6 meters, I need a main disconnect....
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Why would you need a main if there are only 5 taps?
Don
 
I'm still not clear on this.
if a tap box on a group metering system does not have main disconnect.
how many combination meter/tennant breakers could you feed off of the tap box? an endless amount?
isnt the code saying that there are to be no more than 6 movements to completely disconnect the riser or lateral conductors?
if so where are the 6 movements to shut it down.
 
I'm confused. I thought the six movements were to shut off the service to the building, since when do you have to shut down the service conductors (presumably in a trough or cabt).
 
ok to shut off the service to the building. if the group metering does not have a single main disconnect. and there are more than 6 meters and tennant breakers feeding an establishment lets say 10 meters with 10 tennant breakers ,how does this satisfy code?
 
Don, I'm glad to see you've sucessfully confused several of us. :D :D

I guess I just don't see the point of a six handle rule with this exception flatly defying it. It just doesn't make sense. It's as though this completely overrides the six handle rule. :confused:

BTW, M. D. slipped me a link to this article by Mark Ode that is also a good read on this topic. But I'm still scratching my head on this one.

I don't doubt you for a second, all the evidence and wording seems to back you up, but this is frying my brain.
 
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