# Transfer Switch/Main Bonding



## mrcastrovinci (Jan 10, 2011)

All,
Just started getting into these generac's......I'm doing a 20KW (standby genset) and I have an auto transfer switch with a solid neutral. Now the transfer switch has a 200A disconnect. I am trying to understand, does the main panel now become a sub where I have to seperate the neutrals/grounds and then bond at the transfer switch? or does the transfer switch just stay a disconnect and I leave the main panel as a main. I realize since this is not an SDS I need to remove the bond at the genset. :blink:


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## Nyspark21 (Dec 15, 2011)

The main panel does become a sub panel. You do have to separate your grounds and neutrals.


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## mrcastrovinci (Jan 10, 2011)

Makes sense.....thanks for the clarification since its always been my understanding you may only be bonded together in one spot and never two (its this application anyways) thus why in an non sds you must seperate them. Thanks!


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## leland (Dec 28, 2007)

Are you switching the neutral?
Or just transferring the 2 hots?

If the service comes to the meter,bonded,then just to the -service rated -fused-disconnect/transfer- neutral unbroken- you are all set.


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## mrcastrovinci (Jan 10, 2011)

leland said:


> Are you switching the neutral?
> Or just transferring the 2 hots?
> 
> If the service comes to the meter,bonded,then just to the -service rated -fused-disconnect/transfer- neutral unbroken- you are all set.


Its a not a sds so the neutral is not switched. Im not sure i understand what you replied......are you saying i dont need to mess with the main panel neutral/grounds? I believe the generac transfer switch's neutral is not bonded to the box which confuses me so is the main panel still the main panel?


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## 3xdad (Jan 25, 2011)

mrcastrovinci said:


> All,
> Just started getting into these generac's......I'm doing a 20KW (standby genset) and I have an auto transfer switch with a solid neutral. Now the transfer switch has a 200A disconnect. I am trying to understand, does the main panel now become a sub where I have to seperate the neutrals/grounds and then bond at the transfer switch? or does the transfer switch just stay a disconnect and I leave the main panel as a main. I realize since this is not an SDS I need to remove the bond at the genset. :blink:


How do you remove the bond at the generator?


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## 3xdad (Jan 25, 2011)

mrcastrovinci said:


> Its a not a sds so the neutral is not switched. Im not sure i understand what you replied......are you saying i dont need to mess with the main panel neutral/grounds? I believe the generac transfer switch's neutral is not bonded to the box which confuses me so is the main panel still the main panel?


The generac 200ATS has a bond to the can right below the N block. Strap and nut i believe.


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## Bulldog1 (Oct 21, 2011)

Is your ATS service rated?

It is if it has a 200A disconnect in it. It becomes your service like everyone stated.


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## mrcastrovinci (Jan 10, 2011)

Bulldog1 said:


> Is your ATS service rated?
> 
> It is if it has a 200A disconnect in it. It becomes your service like everyone stated.


Yes it is service rated... I guess that explains it in itself.


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## noarcflash (Sep 14, 2011)

the service entrance cable comes off the meter pan, and goes into the main panel. now your cutting a transfer switch in between.

do you need a fused disconnect at the meter pan?


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## mrcastrovinci (Jan 10, 2011)

noarcflash said:


> the service entrance cable comes off the meter pan, and goes into the main panel. now your cutting a transfer switch in between.
> 
> do you need a fused disconnect at the meter pan?


 
No the service entrance cable comes off the meter into the transfer switch (which has a 200A disconnect) then it goes to the panel on one side of the breaker and on the other side to the generator


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## noarcflash (Sep 14, 2011)

then I clearly see the need for a Neutral and Ground at the transfer switch.

and a complete separation of neutrals and grounds in the main house panel,

correct?

(transfer switches not my specialty)


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## 3xdad (Jan 25, 2011)

3xdad said:


> How do you remove the bond at the generator?


Bump.


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## mrcastrovinci (Jan 10, 2011)

3xdad said:


> Bump.


 
From what I see inside the genset is a terminal block where you can seperate all that.


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## Bulldog1 (Oct 21, 2011)

mrcastrovinci said:


> From what I see inside the genset is a terminal block where you can seperate all that.



Kohlers have a bonding jumper in the generator you either leave or remove depending on your situation.


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## 3xdad (Jan 25, 2011)

mrcastrovinci said:


> From what I see inside the genset is a terminal block where you can seperate all that.


i'm pretty sure they are separated in the Generac 20kw, but i will do some checking.


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## 3xdad (Jan 25, 2011)




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## Bulldog1 (Oct 21, 2011)

3xdad said:


> i'm pretty sure they are separated in the Generac 20kw, but i will do some checking.



Most of the generators we have installed come with the bonding jumper connected. I know Kohlers come that way for sure.


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## B4T (Feb 10, 2009)

Bulldog1 said:


> Most of the generators we have installed come with the bonding jumper connected. I know Kohlers come that way for sure.


I have never seen a Generac with one or any kind of literature making reference to a bond.. :blink::blink:


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## Bulldog1 (Oct 21, 2011)

B4T said:


> I have never seen a Generac with one or any kind of literature making reference to a bond.. :blink::blink:



We don't install generacs...:no:


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## mrcastrovinci (Jan 10, 2011)

3xdad said:


>


Pictures show it perfectly, just wish they made bigger strips. I seem to always have bigger wire left over from other jobs and cant fit it under the strips. Then its Bug time.


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## B4T (Feb 10, 2009)

mrcastrovinci said:


> Pictures show it perfectly, just wish they made bigger strips. I seem to always have bigger wire left over from other jobs and cant fit it under the strips. Then its Bug time.


I agree.. they sent out a survey yesterday and I mentioned about using bigger lugs on the neutral bar..


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## manchestersparky (Mar 25, 2007)

If your installing the service rated transfer switch between the meter and the inside panel then the transfer switch has just become the main service disconnecting means. So with that in mind your inside panel is now a subpanel and must be fed with a seperate neutral and ground. You need to seperate the neutrals and grounds in what is now your subpanel. You must also take all grounding electrode conductors to the new main service disconnecting means. If they are too short you can splice them as long as itis an irreversible splice.

Question: Is the service a 200 amp service with just 1 panel or larger with numerous panels ?

I ask as I quite often see a grouping of the mains violation with residential generators.


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## mrcastrovinci (Jan 10, 2011)

manchestersparky said:


> If your installing the service rated transfer switch between the meter and the inside panel then the transfer switch has just become the main service disconnecting means. So with that in mind your inside panel is now a subpanel and must be fed with a seperate neutral and ground. You need to seperate the neutrals and grounds in what is now your subpanel. You must also take all grounding electrode conductors to the new main service disconnecting means. If they are too short you can splice them as long as itis an irreversible splice.
> 
> Question: Is the service a 200 amp service with just 1 panel or larger with numerous panels ?
> 
> I ask as I quite often see a grouping of the mains violation with residential generators.


 
Just 1 Panel.

Does anyone know why the instructions say to run two conduits, one for control wires and one for the power. I understand that the seperation is for DC and A/C, but when ever I see pictures of other installations I always see one conduit ran, plus generac only gives you one hole? Is there a loop hole when I only have to run one conduit. I always punch another hole and run two.


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## 3xdad (Jan 25, 2011)

Two pipes.










Two pipes.










Feel better?:thumbup:

The 3/4 they provide is for your control circuits. The rest is up to you. Install however you want (field install).


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