230.70

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Does this wording look correct to you. I never noticed it before --

VI. Service Equipment — Disconnecting Means
230.70 General. Means shall be provided to disconnect all
conductors in a building or other structure from the service entrance
conductors.
 

fmtjfw

Senior Member
If the GEC is connected in the meter socket or CT cabinet, then the grounded conductor which is a service conductor serves to also conduct any current from the GEC.
 

al hildenbrand

Senior Member
Location
Minnesota
Is there an exception for the grounded conductor? Not by book.
There's not an exception, but there is:

230.75 Disconnection of Grounded Conductor. Where the service disconnecting means does not disconnect the grounded conductor from the premises wiring, other means shall be provided for this purpose in the service equipment. A terminal or bus to which all grounded conductors can be attached by means of pressure connectors shall be permitted for this purpose. In a multisection switchboard, disconnects for the grounded conductor shall be permitted to be in any section of the switchboard, provided any such switchboard section is marked.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
There's not an exception, but there is:
230.75 Disconnection of Grounded Conductor. Where the service disconnecting means does not disconnect the grounded conductor from the premises wiring, other means shall be provided for this purpose in the service equipment. A terminal or bus to which all grounded conductors can be attached by means of pressure connectors shall be permitted for this purpose. In a multisection switchboard, disconnects for the grounded conductor shall be permitted to be in any section of the switchboard, provided any such switchboard section is marked.

Many large switchboards will have a small piece of buss bar that is labeled as the disconnect and can be unbolted for this.


Roger
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
So it seems like 230.70 says one thing and 230.75 says the other. We all know we never had to disconnect the grounded conductor but IMO, this section should be changed to say all ungrounded service conductors no all service conductors.

It is confusing to have to go to 2 different sections when that can be given in one. 230.75 can stay but 230.70 needs a re-write, IMO
 
the definition of service in NEC is coductors supplying power. Definition of service conductors is conductors from the service point to the disconnecting means. So in the definition of service conductors do they mean just conductors supplying power?
 

augie47

Moderator
Staff member
Location
Tennessee
Guess I'm lost. Seems 230.75 simply supplements 230.70.
230.70 requires disconnecting of all service conductors and 230.75 allows an optional (and most often used) method of disconnecting the grounded conductor.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Guess I'm lost. Seems 230.75 simply supplements 230.70.
230.70 requires disconnecting of all service conductors and 230.75 allows an optional (and most often used) method of disconnecting the grounded conductor.

That's correct but it should be stated in the same section, IMO. You red 230.70 then there should be an exception for the grounded conductor. or 230.70 should just state ungrounded service conductors. It would just be easier to understand rather than have to go to 2 places.
 

roger

Moderator
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Location
Fl
Occupation
Electrician
Guess I'm lost. Seems 230.75 simply supplements 230.70.
230.70 requires disconnecting of all service conductors and 230.75 allows an optional (and most often used) method of disconnecting the grounded conductor.
I agree, 230.75 just makes it clear that if the disconnecting means described in 230.70 does not open the grounded conductor there are other methods of doing it.

Roger
 

GoldDigger

Moderator
Staff member
Part of the problem may be that we see "Service Equipment Disconnecting Means" and our thoughts go immediately to the Service Disconnect which includes the main OCPD. We are not primed to think of multiple disconnects working together for the purpose of this section. In particular this portion does not relate to overcurrent protection, which is not needed for the grounded conductor.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
You would disconnect it if you where doing insulation testing.
I was referring to a service install where we never switch the neutral unless it is a separately derived system.

On another note-- how would one connect a neutral to a service and not have it capable of being disconnected. It seems a round about way to say that you don't have to switch the grounded conductor. Again what situation would not satisfy this section-
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
I agree, 230.75 just makes it clear that if the disconnecting means described in 230.70 does not open the grounded conductor there are other methods of doing it.

Roger
I agree it is clear Roger , I am saying it seems round about and sloppy to say it this way
 
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