# Question on replacing a panel



## JoeKan (Sep 30, 2011)

Here's the situation I'm in. The main Disconnect on the far right is 400 amp. Feed is coming into the trough and is spliced. One is going into the disconnect (200amp) and is then feeding another panel. The other splice is feeding the panel in the middle. The customer is wanting that panel removed and replaced. 
The feed going into that panel is 4/0 and I "believe" its a 200 amp. My question is that the right size wire or should I replace it with 2/0? Also would you put a main disconnect in the panel just for when you want to shut that panel off and not the other one? 
I think the wire needs to be replaced with the right size wire and there needs to be a main in the new panel being installed. Customer doesn't have much money and trying to save him money and do the right thing 
Thanks for your help,
Joe


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## J F Go (Mar 1, 2014)

I'd just change out the panel and yes I'd put a main breaker panel in as a means of disconnect. Put the main breaker towards the gutter and if it makes you feel better you could always use a 150 A M.B.P. That would be better than taking those split bolts apart.


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## readydave8 (Sep 20, 2009)

I don't understand why you would need to replace 4/0 with 2/0?


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## Navyguy (Mar 15, 2010)

I can't see that little panel being fed with 4/0... Can you fit 3 @ 4/0 in a 2" pipe?

Cheers
John


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## JoeKan (Sep 30, 2011)

Navyguy said:


> I can't see that little panel being fed with 4/0... Can you fit 3 @ 4/0 in a 2" pipe?
> 
> Cheers
> John


Yes you can, I'm told this panel was installed in the 1980s


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## HackWork (Oct 2, 2009)

Navyguy said:


> I can't see that little panel being fed with 4/0... Can you fit 3 @ 4/0 in a 2" pipe?
> 
> Cheers
> John


Of course, that's the typical 200A service (with aluminum conductors).


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## HackWork (Oct 2, 2009)

readydave8 said:


> I don't understand why you would need to replace 4/0 with 2/0?


Me either. Is this something to do with the tap rules?


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## Navyguy (Mar 15, 2010)

HackWork said:


> Of course, that's the typical 200A service (with aluminum conductors).


Duh... I am not sure what I was even thinking... <smacks forehead>

Been a long day for sure...

Cheers
John


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## JoeKan (Sep 30, 2011)

It's copper wire but I am thinking its overkill. But if its been like that since the 1980s why not leave well enough alone?


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## JoeSparky (Mar 25, 2010)

There should be a main ocpd in the panel you replace. Those are tap conductors and need the correct size protection, because the main ahead of them is 400 amp. 4/0 cu is slightly overkill for 200a. I wouldn't waste one second replacing it. Leave it, and the nipple right where it is. Put a new 200 amp 40 circuit MCB panel right on top of the existing nipple. If you think the wires are too short, install the panel upside down.


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## HackWork (Oct 2, 2009)

JoeKan said:


> It's copper wire but I am thinking its overkill. But if its been like that since the 1980s why not leave well enough alone?


Why would you do more work to get rid of overkill? Overkill is only bad when it's wasting money. But in this case it's already installed.


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## macmikeman (Jan 23, 2007)

JoeSparky said:


> *There should be a main ocpd in the panel you replace. Those are tap conductors and need the correct size protection, because the main ahead of them is 400 amp. 4/0 cu is slightly overkill for 200a. I wouldn't waste one second replacing it.* Leave it, and the nipple right where it is. Put a new 200 amp 40 circuit MCB panel right on top of the existing nipple. If you think the wires are too short, install the panel upside down.


I dunno man, have we asked if there are any fuses inside that "400 AMP DISCONNECT yet? Maybe it has 200's .


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## JoeSparky (Mar 25, 2010)

macmikeman said:


> I dunno man, have we asked if there are any fuses inside that "400 AMP DISCONNECT yet? Maybe it has 200's .


Well, you might be right. However my answer stays the same. Resi MCB load centers are cheaper then ML.


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## HertzHound (Jan 22, 2019)

The wires coming from the disconnect look like at least 500s, I would think it has 400amp fuses. If that’s the case 480.36 would require a main breaker.

If the wire is aluminum, 4/0 would be the minimum size. Even if it’s residential. That panel doesn’t serve the whole house. So no reduction in size. 

But I’m making a lot of assumptions.


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## JoeKan (Sep 30, 2011)

Couple more questions. The Main has 400 amp fuses and is feeding the panel I'm replacing and another one. I don't have a ground coming into the panel I just replaced. The Main has a ground coming in from the grounding rod, then it has the neutral (going to the panel I've replaced) landed on the same lug as the ground coming in. 
I'm thinking for me to get this panel grounded, I need to come off of line side ground with #2 and run it into the panel I just installed. Is that the right idea?


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## JoeKan (Sep 30, 2011)

Here's what I'm talking about


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## JoeKan (Sep 30, 2011)

Would I be okay to drive a ground rod for the panel I just installed?


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## HertzHound (Jan 22, 2019)

You don’t need another ground rod. Everything is metallic conduit. The panel is picking up the ground through the raceways. All you need is a ground bar in the panel. 

The service is the 400 amp fused disconnect. Once it leaves there, it’s just feeders. Only regular locknuts needed to carry the equipment ground to the panel.


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## HertzHound (Jan 22, 2019)

Also, neutrals and ground are separated in the panel you replaced.


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## HackWork (Oct 2, 2009)

Yes, HertzHound is correct. Those panels are not part of the service. The service ends at the disconnect. 

I don't know why they spliced in that trough instead of just installing 2 lugs in the disco and separate feeders to each panel.

Honestly, I don't know why they installed that expensive disco at all. What's common around here is to bring a pair of 200A service entrance conductors in from the meter and land one on the 200A disco on the left and the other on the 200A main breaker panel on the right. That would be 2 out of 6 allowable disconnects. In this situation the smaller disconnect and main breaker panel would be the service disconnects and the GEC's would land there.


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## JoeKan (Sep 30, 2011)

Ok, so I have the neutral and ground bars separated in the new panel. But where do I pick up the ground wire at?


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## JoeKan (Sep 30, 2011)

Can I go from the main water line to the ground bar in the new panel?


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## HackWork (Oct 2, 2009)

JoeKan said:


> Ok, so I have the neutral and ground bars separated in the new panel. But where do I pick up the ground wire at?


You don't. As HH explained, the raceway is the EGC. 

A) Make sure that the green screen is not connecting the neutral bar to the backpanel in your new panel.

B) Install a ground bar to the backpanel to land all of the branch circuit EGCs.



JoeKan said:


> Can I go from the main water line to the ground bar in the new panel?


No.

These are what we would normally call "sub panels". The "main panel" is the 400A disco. That is where the service ends. There is no need to bring a GEC into anything after that 400A disco.


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## JoeKan (Sep 30, 2011)

I did that. So there's no grounding wire coming out of the trough into the ground lug for the ground bar. So am I good? 
This is giving me a headache.


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## HackWork (Oct 2, 2009)

JoeKan said:


> I did that. So there's no grounding wire coming out of the trough into the ground lug for the ground bar. So am I good?
> This is giving me a headache.


Yes.

Joe, you are an IBEW journeyman. Maybe the headache is because you are not yet qualified to be doing this?


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## CoolWill (Jan 5, 2019)

JoeKan said:


> Ok, so I have the neutral and ground bars separated in the new panel. But where do I pick up the ground wire at?



If you really want a wire EGC, you can take it from the neutral in the 400 amp disconnect. But if you do that, you'll need to bond it to the trough too.


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## HackWork (Oct 2, 2009)

CoolWill said:


> If you really want a wire EGC, you can take it from the neutral in the 400 amp disconnect. But if you do that, you'll need to bond it to the trough too.


Good call, I didn't even think of that.

Another example of the NEC being stupid.


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## JoeKan (Sep 30, 2011)

Well she's done. I've spoken to 3 owners, 1 service truck driver and EE and they're all telling me it needs a ground. 
Hackwork, you've given me good advice up until that last comment. I've chosen to ignore it, this time.


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## HackWork (Oct 2, 2009)

JoeKan said:


> Well she's done. I've spoken to 3 owners, 1 service truck driver and EE and they're all telling me it needs a ground.


 It *has* a ground.



> Hackwork, you've given me good advice up until that last comment. I've chosen to ignore it, this time.


The last comment was good advice too, so you shouldn't ignore it. You are not qualified to be doing this type of work. Stop with the sidework before you kill someone.

You were given good advice a year and a half ago when you first posted this: https://www.electriciantalk.com/f2/my-next-project-254409/#post4915585


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## yamatitan (Sep 4, 2010)

JoeKan said:


> Well she's done. I've spoken to 3 owners, 1 service truck driver and EE and they're all telling me it needs a ground.
> Hackwork, you've given me good advice up until that last comment. I've chosen to ignore it, this time.



You have a ground via the bonding through the conduit back to the disconnect.


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## CoolWill (Jan 5, 2019)

JoeKan said:


> Well she's done. I've spoken to 3 owners, 1 service truck driver and EE and they're all telling me it needs a ground.


You're not listening. It does need a ground, and it has one in the form of a metal pipe. That is acceptable by code. You can certainly install a wire, but it isn't necessary.



> Hackwork, you've given me good advice up until that last comment. I've chosen to ignore it, this time.


What happens next time? Will there be a U Haul truck involved?


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## readydave8 (Sep 20, 2009)

Why did you ask truck driver, JoeKan?


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## Elec Tricks (Nov 17, 2018)

*My inspector doesn't like double lugs on load side of meter*

Hackworth wrote:
Honestly, I don't know why they installed that expensive disco at all. What's common around here is to bring a pair of 200A service entrance conductors in from the meter and land one on the 200A disco on the left and the other on the 200A main breaker panel on the right. 

HackWorth,'
I agree and have done your method a few times, until my inspector claimed that the double lugs are only listed for the input side of the 400 amp meter,not the load side. To get the service turned back on quickly I didn't argue and just retrofitted an ugly auxillary gutter. Has anyone successfully had this discussion with an inspector?


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## HackWork (Oct 2, 2009)

Elec Tricks said:


> Hackworth wrote:
> Honestly, I don't know why they installed that expensive disco at all. What's common around here is to bring a pair of 200A service entrance conductors in from the meter and land one on the 200A disco on the left and the other on the 200A main breaker panel on the right.
> 
> HackWorth,'
> I agree and have done your method a few times, until my inspector claimed that the double lugs are only listed for the input side of the 400 amp meter,not the load side. To get the service turned back on quickly I didn't argue and just retrofitted an ugly auxillary gutter. Has anyone successfully had this discussion with an inspector?


400A meters can be purchased with double lugs. The typical way to install a 400 amp service around here is simply to run two sets of 4/0’s to 200 amp main breaker panels


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## Wardenclyffe (Jan 11, 2019)

Hackworth,...


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## macmikeman (Jan 23, 2007)

CoolWill said:


> You're not listening. It does need a ground, and it has one in the form of a metal pipe. That is acceptable by code. You can certainly install a wire, but it isn't necessary.
> 
> 
> 
> What happens next time? Will there be a U Haul truck involved?


Only if there is a blizzard going on. It needs to be snowing really big time.


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## macmikeman (Jan 23, 2007)

When the story of B4T vs Hax went down, that day was the first time I ever fell in love..........:vs_love::vs_rocking_banana:


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## HackWork (Oct 2, 2009)

B4T and I were going to one day tell the truth about that story, but he died before we could :sad:


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## Easy (Oct 18, 2017)

JoeKan said:


> Would I be okay to drive a ground rod for the panel I just installed?


Be careful here. Supplemental or Auxiliary Grounding Electrodes are not a good thing. You only want one path to earth ground.


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## macmikeman (Jan 23, 2007)

Easy said:


> Be careful here. Supplemental or Auxiliary Grounding Electrodes are not a good thing. You only want one path to earth ground.



Negative. They just need to bonded to each other at some point or another. 
You must supplement water pipe ground electrodes with another type of approved grounding electrodes such as a driven rod or an uffer grounding electrode. Just don't run a supplemental and not bond it to the other electrodes.. that is the bad thing .


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## Easy (Oct 18, 2017)

macmikeman said:


> Negative. They just need to bonded to each other at some point or another.
> You must supplement water pipe ground electrodes with another type of approved grounding electrodes such as a driven rod or an uffer grounding electrode. Just don't run a supplemental and not bond it to the other electrodes.. that is the bad thing .


Yes I agree. What was I thinking. :sad:


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