panel or sub-panel

[mudcat555]

meter is mounted on outside garage wall. on the other side of the wall is a 100 amp dis-connect switch.Breaker panel is located in the middle of the house. Would the 100 amp dis-connect be considered my main panel where ground rod and cold water pipe would be bonded? Would the breaker panel actually be considered a sub-panel and therefore no bonding of the neutral bar at this point?

 

[stud696981]

Re: panel or sub-panel

Anything after the first disconnect would be a sub-panel, all neutrals and grounds are separate. However, the term sub-panel is not in the NEC. Since you have a main disconnect box and that feeds a panel, the panel will be required to have the neutral and grounds to be separate and should be feed with four wires from the disconnect box.

 

[infinity]

Re: panel or sub-panel

Mudcat,

The answer to your question regarding the EGC and supplemental grounding electrode conductor is yes, they would be connected at the 100 amp main disconnect not the subpanel.

 

[charlie]

Re: panel or sub-panel

Mudcat, welcome to the forum.

 

[sparks1]

Re: panel or sub-panel

Originally posted by stud696981:
Since you have a main disconnect box and that feeds a panel, the panel will be required to have the neutral and grounds to be separate and should be feed with four wires from the disconnect box. [/QB]

Or, if you prefer, you could keep it three wire, don't seperate the grounds & neutrals and drive a ground rod at the sub-panel.

[ July 14, 2005, 01:50 PM: Message edited by: sparks1 ]

 

[infinity]

Re: panel or sub-panel

Or, if you prefer, you could keep it three wire, seperate the grounds & neutrals and drive a ground rod at the sub-panel.

You cannot use the earth as the return path for equipment grounding.

[ July 14, 2005, 05:17 AM: Message edited by: infinity ]

 

[benaround]

Re: panel or sub-panel

Sparks1,

I would like to see the code article that backs that up.

frank

 

[hurk27]

Re: panel or sub-panel

Spark's1 Or, if you prefer, you could keep it three wire, separate the grounds & neutrals and drive a ground rod at the sub-panel.

Are you saying to leave the 3 wire feed then separate the grounds and neutral and just connect the grounds to the electrode?

If you are, you need to understand something, Besides that the NEC forbids this, It will create a very dangerous shock hazard if anything that is bonded to this sub panels grounding was to short to the EGC the ground rod will not provide any path back to source with a low enough impedance to open any OCPD device. and all the grounding connected to this sub panel will be at a 120 volt potential to Earth, including the ground rod!

[ July 13, 2005, 10:45 PM: Message edited by: hurk27 ]

 

[don_resqcapt19]

Re: panel or sub-panel

Is the garage attatched or detatched? If detatched, then 250.32 will permit the installation suggested by Sparks.
Don

 

[karl riley]

Re: panel or sub-panel

Does anyone miss Bennie at this point? I wonder if he is looking down and following this forum from wherever he is.
Karl

 

[sparks1]

Re: panel or sub-panel

Originally posted by hurk27:

Are you saying to leave the 3 wire feed then separate the grounds and neutral and just connect the grounds to the electrode?

No!
What I'm saying is this, ground the neutral at the second building. Fault current passes from the the bond wires through the neutral as the earth's impedence is too high.

 

[charlie]

Re: panel or sub-panel

Karl, I have missed him all along. He had some strange ideas but it made for some very good discussions.

 

[iwire]

Re: panel or sub-panel

Originally posted by karl riley:
Does anyone miss Bennie at this point?

Yes I miss him, he and I used to PM quite a lot along with some heated 'debates' on this forum.

 

[al hildenbrand]

Re: panel or sub-panel

From the way MudCat words his original question, it reads, to me, that the garage is attached. If I'm wrong in my assumption, MudCat, ignore what I write next.

The service disconnect is just inside from the meter. The main bonding point between the neutral and the grounding electrode system and all the branch circuit neutrals and all the branch circuit equipment grounds happens at the service disconnect, and only at the service disconnect. . .downstream from the service disconnect (towards the outlets) the neutral must be kept seperate from the grounding electrode system and equipment grounding conductors.

So, in MudCat's case, the panel in the middle of the house must have a neutral bar that is seperate from the ground wires, and this neutral bar must only have neutrals attached to it, and this neutral bar has to "float" without electrical connection to the metal of the box that it is mounted in. The conductors between the location of the service disconnect and panel in the middle of the house will be a feeder. The conductors from the service disconnect in the garage back upstream (towards the power company) out through the meter and to the connection to the power company's conductors are the service entrance conductors.

Edit for typos. It's amazing how many are invisible until the post is in the record - Al

[ July 15, 2005, 04:52 PM: Message edited by: al hildenbrand ]

 

[George Stolz]

Re: panel or sub-panel

I was too late to be here, but I have read some of his many posts, and miss him in a slightly different way; as stupid (sacrilegious) as that sounds. It looks like it was a lot of fun to argue with him, and he appears to never have taken the intellectually easy answer for anything.

I'm just glad that professionals of all ages have access to this forum. Ideas from crazy kids and old-timers mixing make for some interesting reading about a dry code.

 

[karl riley]

Re: panel or sub-panel

Yes, Bennie got my ire up, but he made me think through some assumptions.

As to the wiring question, I have had to deal with magnetic fields from currents on various piping systems in buildings when the breaker panel was well inside a building and the neutral bus was bonded to the panel as if it were the service entrance point.

This gave neutral current many paths throughout the house before it joined up again at the disconnect by the meter.

In deference to Bennie I did not use the word "subpanel".

Karl

 

[charlie]

Re: panel or sub-panel

I never use it either but prefer to use the term distribution panelboard or downstream panelboard.

 

[iwire]

Re: panel or sub-panel

Load-Side Equipment

250.142(B)