# Does main service panel need grounded?



## CarpenterSFO (Dec 12, 2012)

SmallTownGuy said:


> I was just about to mention Missouri.
> 
> A state where I legally bought and hung my own 3-phase transformer, ran my own 3-phase service, and then had the city make the drops.
> 
> ...


Yikes! And you lived to tell us about it.


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## Seven-Delta-FortyOne (Mar 5, 2011)

Tinstaafl said:


> We give some leeway here to contributing members who have demonstrated their expertise in one field or another, giving them a "hand up" as a professional courtesy. But that courtesy does need to be earned, with evidence such as pictures and descriptions of current and past projects, sharing knowledge and so forth.


Is this the Official Policy of ContractorTalk.com?


Delta


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## Tinstaafl (Jan 6, 2008)

Seven-Delta-FortyOne said:


> Is this the Official Policy of ContractorTalk.com?


Of course not, but you've been around here long enough to know that's how it works as an unwritten rule. 

And had you taken the time to _read_ the posts, you would have seen that I already backed off on the statement about no one being able to be less restrictive than the NEC.


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## yzman720 (Dec 29, 2009)

SmallTownGuy said:


> I was just about to mention Missouri.
> 
> A state where I legally bought and hung my own 3-phase transformer, ran my own 3-phase service, and then had the city make the drops.
> 
> ...


This happens all the time in Missouri. That's why it is aggravating when sometimes you get a response of "call your local inspector or bi and just ask" 
when sincerely there are a lot of places in Missouri that do not have one or a local code depending on county
I wanted to thank everyone for the thoughts and inputs to my original question.


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## Seven-Delta-FortyOne (Mar 5, 2011)

Tinstaafl said:


> Of course not, but you've been around here long enough to know that's how it works as an unwritten rule.
> 
> And had you taken the time to _read_ the posts, you would have seen that I already backed off on the statement about no one being able to be less restrictive than the NEC.


You're right. I didn't see that.

And I may have been a bit snarkey in this thread. :whistling


My apologies.



Delta


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## Seven-Delta-FortyOne (Mar 5, 2011)

Double post. :wallbash:



Delta


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## Tinstaafl (Jan 6, 2008)

Seven-Delta-FortyOne said:


> Double post. :wallbash:


Hey, I don't mind if you apologize twice. :laughing::cheesygri


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## 91782 (Sep 6, 2012)

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## kapena (Aug 20, 2004)

yzman720 said:


> I am a little confused on if I need to ground my service panel box inside the home? There is no subpanel
> There is no ufer ground in the footing. On the outside of the home I am running 2 - 5/8" ground rods 6' apart with a continuous #4 bare copper between them and then terminating at the meter base. The home is all electric with no gas and ran completely in pex so there is nothing to ground to inside the home. Does the service panel inside the home need grounding? It is a 200amp service panel.
> I included a pic of my panel if it helps for anything.
> Any input it great appreciated!


I suggest you get the book: "Wiring a House" 5th edition by Rex Cauldwell.


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## Michael217 (Apr 23, 2011)

yzman720 said:


> On the outside of the home I am running 2 - 5/8" ground rods 6' apart with a continuous #4 bare copper between them and then terminating at the meter base.


When you complete the above your main service panel will be grounded and NEC compliant. 

You would also be compliant if you used #6 copper to connect your two rods together and to the meter socket.

In this case your neutral service entrance conductor in the meter socket serves as the grounding conductor to the main service panel.


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## yzman720 (Dec 29, 2009)

I terminated the green screw in the upper right of box next to main breaker bonding the neutral to the panel itself. I am going to call this panel a done job unless anyone sees anything I'm missing? I didn't use the neutral terminal kit that comes with the panels due to it being an all pex ran house and not needing to ground to the water pipes.


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## Michael217 (Apr 23, 2011)

yzman720 said:


> I terminated the green screw in the upper right of box next to main breaker bonding the neutral to the panel itself.


You got it! And, that is a good example of bonding! 

Hope no one minds a little rumbling on here but here goes. Your panel is grounded through the neutral wire when you connected one of the ground rods to the neutral in the meter socket. The other rod is bonded.

The panel in this install is the guts of the breaker box and the (guts)/ panel has been installed in a panel box/cabinet made of steel. Since the steel box is likely to be energized it require bonding.

So, terminating the grounding screw bonded the box to your already grounded panel.


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## GettingBy (Aug 19, 2010)

Michael217 said:


> the steel box is likely to be energized


How so?


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## CarpenterSFO (Dec 12, 2012)

Is there a breaker or main disconnect at the meter panel?


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## Michael217 (Apr 23, 2011)

GettingBy said:


> How so?


Any one of those hot wires could have a nick in the insulation and come in contact with the steel box, which would energize the steel.


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## Michael217 (Apr 23, 2011)

CarpenterSFO said:


> Is there a breaker or main disconnect at the meter panel?


First line from the OP: 

"I am a little confused on if I need to ground my service panel box inside the home? There is no subpanel"


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## CarpenterSFO (Dec 12, 2012)

Michael217 said:


> First line from the OP:
> 
> "I am a little confused on if I need to ground my service panel box inside the home? There is no subpanel"


If you were at the house, and he showed you this panel, and told you he was confused about grounding it, would you go outside and look at the meter box first, or would you just happily start working in the panel?

A significant percentage of small contractors who aren't electricians would get this point wrong.


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## GettingBy (Aug 19, 2010)

Michael217 said:


> Any one of those hot wires could have a nick in the insulation and come in contact with the steel box, which would energize the steel.


Possible. 
I've never heard of a panel box being at 120v w/respect to ground but maybe some sparkys have.
If 10 kA is flowing through the box somebody would know pretty soon.


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## Tinstaafl (Jan 6, 2008)

GettingBy said:


> I've never heard of a panel box being at 120v w/respect to ground but maybe some sparkys have.


I've seen it. Wouldn't have happened if the box was wired properly.


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## maninthesea (Nov 11, 2008)

I'm curious why aluminum on your neutral feed but copper on the hot feeds? Or am I looking at the photo and seeing camera flash reflected from shines new wires?
Jim


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## GettingBy (Aug 19, 2010)

Tinstaafl said:


> I've seen it. Wouldn't have happened if the box was wired properly.


And running a wire to a ground rod would have 120v/(<25 ohms) = >4A or so running into the ground through the wire and the panel would still be at 120v.


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## Irishslave (Jun 20, 2010)

yzman720 said:


> This happens all the time in Missouri. That's why it is aggravating when sometimes you get a response of "call your local inspector or bi and just ask"
> when sincerely there are a lot of places in Missouri that do not have one or a local code depending on county
> I wanted to thank everyone for the thoughts and inputs to my original question.


Yes but this is only in second and third class counties in Missouri....if it's a first class county you're in .....expect to have a licensed sparky and an inspection.....and IMO yes....every main panel should be grounded to earth in some acceptable fashion.....I'm sure there is a provision defined in the NEC.....just don't know what it is.....bury an old truck axle in the ground and run your ground cable to it :laughing:


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## Michael217 (Apr 23, 2011)

GettingBy said:


> And running a wire to a ground rod would have 120v/(<25 ohms) = >4A or so running into the ground through the wire and the panel would still be at 120v.


A property bonded steel panel box, that is the box/cabinet not the breaker panel, is bonded to the neutral/grounded conductor like in the OP's case when the bonding screw was terminated.

Ground rods do very little if nothing at all when there is an over-current fault as in your posted math.

Most and maybe all the fault current will be conducted on the grounded wire/neutral.

So, if one of the many ungrounded/hot wires in the box comes in contact with the steel the excessive current "flow" will be on the neutral.


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## GettingBy (Aug 19, 2010)

Michael217 said:


> So, if one of the many ungrounded/hot wires in the box comes in contact with the steel the excessive current "flow" will be on the neutral.


Which means up to 10kA will flow for a half-cycle or so before the breakers trip, less if your pole transformer is aways down the block. :thumbsup:


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## Seven-Delta-FortyOne (Mar 5, 2011)

So is the neutral bonded to the meter enclosure as well? :blink:




Delta


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## CarpenterSFO (Dec 12, 2012)

Seven-Delta-FortyOne said:


> So is the neutral bonded to the meter enclosure as well? :blink:
> Delta


No one's answering questions.


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## Seven-Delta-FortyOne (Mar 5, 2011)

This is why I'm always wary about answering electrical questions for people who don't have a strong background in electrical.

One guy gives the 'Looks good from my house" answer, and the OP is content, but he may have just made a possibly fatal mistake. :blink:

I give up.



Delta


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## Michael217 (Apr 23, 2011)

Seven-Delta-FortyOne said:


> So is the neutral bonded to the meter enclosure as well? :blink:
> 
> 
> 
> ...


Yes the grounded/neutral conductor is connected at the meter socket and it is complaint. 

This connection is bonding the meter socket to the grounded conductor. These lugs are in direct contact with the steel socket box, so they effectively bond the socket to the grounded conductor.

Connecting the grounding electrode conductor at the socket is the bonding of the electrode grounding system.

Here is an image I copied off the web. Notice the grounded conductor lugs and just to the right a smaller lug. The smaller lug is for the grounding electrode conductor.










Chapter 250 of the NEC is the most miss-understood part of the code. It has taken me years of steady study to understand it better and I could use addition work. Answering questions is helping me solidify the subject.

It helps the understanding if the neutral/common conductor is referred to (as described in the NEC) as a Grounded Conductor.


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## CarpenterSFO (Dec 12, 2012)

Michael217 said:


> Yes the grounded/neutral conductor is connected at the meter socket and it is complaint.
> 
> ....
> 
> Here is an image I copied off the web. .... .


I'm confused - are you the original poster? How do you know what the O.P.'s meter socket looks like? I thought the O.P. had a different name? What the heck does a picture off of the web have to do with the O.P.'s install?


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## Seven-Delta-FortyOne (Mar 5, 2011)

Michael217 said:


> Yes the grounded/neutral conductor is connected at the meter socket and it is complaint.
> 
> This connection is bonding the meter socket to the grounded conductor. These lugs are in direct contact with the steel socket box, so they effectively bond the socket to the grounded conductor.
> 
> ...



Hey BuckWheat, You have no idea if the installation is code compliant or not, I know what a grounding lug is, and how it attaches to a metal enclosure, and the neutral has been called a Grounded Conductor for a long time. 

What you don't understand is the difference between Grounding and Bonding, or where and when a neutral should be grounded.



You know, forget it.................


There was a lot more, but I need to go refill my drink.........



Delta


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## CarpenterSFO (Dec 12, 2012)

We don't know (and Michael217 doesn't know) if there's a disconnect or main breaker out at the meter. There often is. If there is, then bonding the neutral in the panel violates NEC 250.24(A)(5), which says that the neutral shouldn't be bonded to ground anywhere on the load side of the main disconnect.

NEC 250.24(A) says that a system should have a grounding electrode conductor, and refers to the grounding electrode conductor connection. That is, there is one grounding conductor, and one connection. I think that Michael217's post with the meaningless picture from the web suggests that the meter box should also be bonded and have a grounding electrode, though from the language it is a little unclear. Either location is permitted for the connection to the grounding electrode, but not both. If both are connected, then the grounding system becomes current-carrying, under normal, non-fault conditions. 

We don't know enough about the the situation or the O.P. to give safe advice, except to get someone in who isn't confused about grounding and bonding.


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## Michael217 (Apr 23, 2011)

I can see you two are pigs! I don't fight with pigs!


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## CarpenterSFO (Dec 12, 2012)

Michael217 said:


> I can see you two are pigs! I don't fight with pigs!


Trying to keep the original poster and other folks on the internet from being electrocuted is not mud-wrestling. If you have something to share that will educate me or Delta, or the internet viewing public, you should share it.

Mud-wrestling would be, for example, calling each other names.


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## Michael217 (Apr 23, 2011)

CarpenterSFO said:


> Trying to keep the original poster and other folks on the internet from being electrocuted is not mud-wrestling. If you have something to share that will educate me or Delta, or the internet viewing public, you should share it.
> 
> Mud-wrestling would be, for example, calling each other names.


Maybe you should direct the mud-wrestling to whomever start it.

You seem civil so I'll comment.

No where in my post with the picture is there a suggestion or otherwise that bonding should occur in both the socket and the main disconnect. That was a far assumption. Why? To discredit maybe?

Once again, in the OP's first line he used language to state that there is no meter/main or other disconnect device ahead of the main panel.

If you want to hold his hand, that's your business, not mine, leave me out of it.


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## Seven-Delta-FortyOne (Mar 5, 2011)

CarpenterSFO said:


> Mud-wrestling would be, for example, calling each other names.


Well, in all fairness, I did call him "BuckWheat". :laughing: :lol:

I'm done with this thread. We've both tried to steer them in the right direction, but to no avail.

You can lead a horse to water...blah, blah...



Delta


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## CarpenterSFO (Dec 12, 2012)

Michael217 said:


> ...
> No where in my post with the picture is there a suggestion or otherwise that bonding should occur in both the socket and the main disconnect. That was a far assumption. Why? To discredit maybe?


I'm sure I misunderstood what you said.



Michael217 said:


> Once again, in the OP's first line he used language to state that there is no meter/main or other disconnect device ahead of the main panel.


You mean where he said there's no sub-panel, and where a reasonable person would take that to mean that the panel in the picture isn't a sub, and that there isn't a main disconnect where the meter is. I know exactly what you mean.

Unfortunately, we don't know exactly what he means by that, and in fact, because we know that he's confused (his word), we have no idea at all what he means by that. And it is dangerous to him, to assume that he means what you mean.
[/QUOTE]



Michael217 said:


> If you want to hold his hand, that's your business, not mine, leave me out of it.


I'm not interested in holding his hand at all. I want not to usher him to an early grave, though.

This is the internet, and anyone can look at your post, and say "I don't have a sub-panel either, so that how a fuse-box should be wired." That's why you'll find some hostility to electrical how-to, and similarly to structural how-to that should be supplied by an engineer.


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## GettingBy (Aug 19, 2010)

Some of the bruthas be gettin' in a state of high dudgeon! :blink:


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## Irishslave (Jun 20, 2010)

CarpenterSFO said:


> I'm sure I misunderstood what you said.
> 
> 
> You mean where he said there's no sub-panel, and where a reasonable person would take that to mean that the panel in the picture isn't a sub, and that there isn't a main disconnect where the meter is. I know exactly what you mean.


This is exactly what I thought the only place neutral and ground were not bonded was in a sub panel and I've heard it wasn't necessary to separate them.....but it is code 

I have also seen a GR w/ cable at a meter base with a remote disconnect many times....especially in trailer parks


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