# 3 Wire Feeder



## Roger123 (Sep 23, 2007)

A setting where their are two detached garages where the 1st garage is being fed with an existing & code compliant 3 wire feeder from a main disconnect at the house.

Can the second garage be fed with a 4 wire feeder from the 1st garage?

In other words, can an existing & code compliant 3 wire feeder be extended?


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## Bulldog1 (Oct 21, 2011)

Roger123 said:


> A setting where their are two detached garages where the 1st garage is being fed with an existing & code compliant 3 wire feeder from a main disconnect at the house.
> 
> Can the second garage be fed with a 4 wire feeder from the 1st garage?
> 
> In other words, can an existing & code compliant 3 wire feeder be extended?



Yes but it needs it's own disconnect and 4 conductors and grounding.


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## RIVETER (Sep 26, 2009)

Roger123 said:


> A setting where their are two detached garages where the 1st garage is being fed with an existing & code compliant 3 wire feeder from a main disconnect at the house.
> 
> Can the second garage be fed with a 4 wire feeder from the 1st garage?
> 
> In other words, can an existing & code compliant 3 wire feeder be extended?


Are you calling a three wire feeder a neutral and two hots?


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## 480sparky (Sep 20, 2007)

RIVETER said:


> Are you calling a three wire feeder a neutral and two hots?



He is. There is only 3 conductors between the first building and the main house.


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## RIVETER (Sep 26, 2009)

480sparky said:


> He is. There is only 3 conductors between the first building and the main house.


That is what I was thinking. What about the mechanical ground to the third building?


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## Roger123 (Sep 23, 2007)

bump


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## McClary’s Electrical (Feb 21, 2009)

Roger123 said:


> bump


 
With a disconnect, and GES, it would be legal. Assuming that the original 3 wire was done on '05 code or before with no other metallic paths between the house and first garage. Make sure the first building has a GES also.


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## chicken steve (Mar 22, 2011)

Should we crank up the 250-32 wayback machine?


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## Bulldog1 (Oct 21, 2011)

mcclary's electrical said:


> With a disconnect, and GES, it would be legal. Assuming that the original 3 wire was done on '05 code or before with no other metallic paths between the house and first garage. Make sure the first building has a GES also.




I guess my answer is not what he wanted to hear? :laughing:


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## McClary’s Electrical (Feb 21, 2009)

Bulldog1 said:


> I guess my answer is not what he wanted to hear? :laughing:


I thought you nailed it.


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## Roger123 (Sep 23, 2007)

Thanks for both replies guys. Always good to get a few opinions.


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## Dennis Alwon (May 9, 2009)

I don't see why you couldn't run a 4 wire to the second garage from the first garage that only has a 3 wire feeder.


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## amptech (Sep 21, 2007)

Dennis Alwon said:


> I don't see why you couldn't run a 4 wire to the second garage from the first garage that only has a 3 wire feeder.


I agree. That would be the only way to comply with current code.


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## RePhase277 (Feb 5, 2008)

This is basically the same setup as the three-wire service entrance, without a meter.

I don't see why it would be wrong.


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## Roger123 (Sep 23, 2007)

There was one opinion from a respected electrician that saw it as an extension of a three wire feeder and advised that the code prohibited an extension of a two wire ungrounded receptacle circuit without grounding the new/additional receptacle and thought that maybe there was a comparison. Just saying.


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## RIVETER (Sep 26, 2009)

mcclary's electrical said:


> With a disconnect, and GES, it would be legal. Assuming that the original 3 wire was done on '05 code or before with no other metallic paths between the house and first garage. Make sure the first building has a GES also.


Are you implying that with a disconnect and a GES it would be classified as a service to the third building?


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## chicken steve (Mar 22, 2011)

InPhase277 said:


> This is basically the same setup as the three-wire service entrance, without a meter.
> 
> I don't see why it would be wrong.


 
well it's a rather _glaring_ double stanrad that the poco can proliferate point of use with a dual usage _(noodle and ground)_ conductor

but _we _can't....

~CS~


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## McClary’s Electrical (Feb 21, 2009)

RIVETER said:


> Are you implying that with a disconnect and a GES it would be classified as a service to the third building?


Read the definition of service


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## BBQ (Nov 16, 2010)

RIVETER said:


> Are you implying that with a disconnect and a GES it would be classified as a service to the third building?


As he mentioned, it was only recently we were required to run an EGC to a separate building.

This has nothing to do with services, it was / is still a feeder.


I am pretty sure Mike Holt put in the proposal to require an EGC with all feeders to separate buildings or structures.


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## RePhase277 (Feb 5, 2008)

Basically, the answer is still "yes" you can run a 4-wire feeder from a 3-wire panel. Because a feeder is just a big branch circuit, and no one would blink running a 4-wire branch from a 3-wire panel, as long as the original panel is correctly installed and bonded.


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## Shockdoc (Mar 4, 2010)

But what about grounding at the main garage ? two ground rods or a waterpipe connection.


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## McClary’s Electrical (Feb 21, 2009)

Shockdoc said:


> But what about grounding at the main garage ? two ground rods or a waterpipe connection.


If there's a metal water pipe from the main house to garage, you can't use a 3 wire feeder.

If there's a standalone water system to garage that qualified as an electrode, it would have to be used in you grounding electrode system.


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## RGH (Sep 12, 2011)

I agree with Mc., nuetral is isolated but you need bonding at 2nd panel. 3 wire gives no grd bond. I would pull the 4 wire and drive the rod at 2nd bld too if there is no water bond available at 2nd bdl. IMO


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