Concrete encased electrode connection at service

[powermac36]

While inspecting a 120/240 v, 1-phase, 400 amp service, I found the #4 concrete encased electrode connected to a lug "outside" the metal enclosure of the main disconnect.

I failed the inspection citing article 250.24(A)(1) stating: the connection shall be inside on the equipmemt/grounded bus bar.

My fellow electrical inspectors felt that the aritilce did not preclude an exterior CEC connectiion, if all other servioce groudning ok.

What do other professionls think??

 

[bphgravity]

Re: Concrete encased electrode connection at service

Where do you read, "..shall be inside.."?

Would you not permit the connection to be made at the service point?

 

[powermac36]

Re: Concrete encased electrode connection at service

Thanks for the comment.

yes, I give you the article says "service point" as a connection area. There is another area of connection that article 250.24(a)(1)references:

the terminal or bus to which the grounded service conductor is connected at the service disconnecting means.

This is where I got "inside on the equipment/grounded bus bar".

You thoughts??

 

[iwire]

Re: Concrete encased electrode connection at service

powermac36, I agree with you.

250.24(A) System Grounding Connections. A premises wiring system supplied by a grounded ac service shall have a grounding electrode conductor connected to the grounded service conductor, at each service, in accordance with 250.24(A)(1) through (A)(5).

(1) General. The connection shall be made at any accessible point from the load end of the service drop or service lateral to and including the terminal or bus to which the grounded service conductor is connected at the service disconnecting means.

In my opinion attaching a GEC to the enclosure is not what 250.24(A)(1) allows.

The choices are the grounded conductor, terminal or bus, there are no other options.

If there where other options in my opinion they would be listed similar to 820.40(B)

Take a look 820.40(B)(1)(5)

820.40(B) Electrode. The grounding conductor shall be connected in accordance with 820.40(B)(1) and (B)(2).

(1)In Buildings or Structures with Grounding Means. To the nearest accessible location on the following:

(1)The building or structure grounding electrode system as covered in 250.50;

(2)The grounded interior metal water piping system, within 1.52 m (5 ft) from its point of entrance to the building, as covered in 250.52;

(3)The power service accessible means external to enclosures as covered in 250.94;

(4)The metallic power service raceway;

(5)The service equipment enclosure;

(6)The grounding electrode conductor or the grounding electrode conductor metal enclosure; or

(7)The grounding conductor or the grounding electrode of a building or structure disconnecting means that is grounded to an electrode as covered in 250.32.

[ March 19, 2005, 07:45 PM: Message edited by: iwire ]

 

[benaround]

Re: Concrete encased electrode connection at service

powermac32,Iwire ,

How would that differ from this example:

Meter outside,MCB panel in the basement,factory neutral bar bonded to enclosure by strap or screw,GEC terminated to equipmemt ground bus that is screwed to enclosure, but not directly connected as in the OP.

frank: I also agree with your method ,but---

 

[don_resqcapt19]

Re: Concrete encased electrode connection at service

benaround,

Meter outside,MCB panel in the basement,factory neutral bar bonded to enclosure by strap or screw,GEC terminated to equipmemt ground bus that is screwed to enclosure, but not directly connected as in the OP.

The GEC connection to the equipment grounding bus is only permitted where the main bonding jumper is a wire or busbar. I'm not sure if the bonding strap is a busbar.

250.249A0(4) Main Bonding Jumper as Wire or Busbar. Where the main bonding jumper specified in 250.28 is a wire or busbar and is installed from the neutral bar or bus to the equipment grounding terminal bar or bus in the service equipment, the grounding electrode conductor shall be permitted to be connected to the equipment grounding terminal bar or bus to which the main bonding jumper is connected.

Don

[ March 19, 2005, 08:09 PM: Message edited by: don_resqcapt19 ]

 

[iwire]

Re: Concrete encased electrode connection at service

Originally posted by benaround:
powermac32,Iwire ,

How would that differ from this example:

Meter outside,MCB panel in the basement,factory neutral bar bonded to enclosure by strap or screw,GEC terminated to equipmemt ground bus that is screwed to enclosure, but not directly connected as in the OP.

In my opinion you are not allowed to land the GEC on the EGC bus either.

I believe the NEC does not want the connection of the GEC to the grounded service conductor to rely on the continuity of the MBJ.

Much like the NEC requires the GEC to be continuous or spiced with irreversible methods.

 

[iwire]

Re: Concrete encased electrode connection at service

After reading Don's post I see I was somewhat mistaken.

You may bring the GEC to the EGC bus in some circumstances.

[ March 19, 2005, 08:20 PM: Message edited by: iwire ]

 

[benaround]

Re: Concrete encased electrode connection at service

Don,Bob

Has anyone told you guys recently--YOU GUYS ARE GOOD !!!!!

thx frank

 

[ga77]

Re: Concrete encased electrode connection at service

"A" grounding electrode must be connected in the service equipment , but not "all".

 

[iwire]

Re: Concrete encased electrode connection at service

Originally posted by ga77:
"A" grounding electrode must be connected in the service equipment , but not "all".

ga77 you have to be careful of how you say that.

If there are no grounding electrodes available one (or 2) ground rods will need to be installed and you are done.

But if there are multiple grounding electrodes available you must connect to all of them.

250.50 Grounding Electrode System.
If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. Where none of these electrodes are available, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.

 

[ga77]

Re: Concrete encased electrode connection at service

Originally posted by iwire:

Originally posted by ga77:
"A" grounding electrode must be connected in the service equipment , but not "all".

ga77 you have to be careful of how you say that.

If there are no grounding electrodes available one (or 2) ground rods will need to be installed and you are done.

But if there are multiple grounding electrodes available you must connect to all of them.

250.50 Grounding Electrode System.
If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. Where none of these electrodes are available, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.

 

[ga77]

Re: Concrete encased electrode connection at service

Originally posted by iwire:

Originally posted by ga77:
"A" grounding electrode must be connected in the service equipment , but not "all".

ga77 you have to be careful of how you say that.

If there are no grounding electrodes available one (or 2) ground rods will need to be installed and you are done.

But if there are multiple grounding electrodes available you must connect to all of them.

250.50 Grounding Electrode System.
If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. Where none of these electrodes are available, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.

What I meant was any additional electrodes after the first one need only to be bonded to the nearest electrode or grounding electrode conductor with the proper size bonding jumper and does not need to go all the way back to the service equipment.

 

[hurk27]

Re: Concrete encased electrode connection at service

Ga77 if you need to change something or add to a post of yours just hit the

But yes to:

What I meant was any additional electrodes after the first one need only to be bonded to the nearest electrode or grounding electrode conductor with the proper size bonding jumper and does not need to go all the way back to the service equipment.

A lug on the outside of the service disconnect or meter can is not an electrode. Even a water pipe that serves as an electrode is not an electrode beyond the 5' mark into the house.