# Meter Main w/ standby Generator



## The_RuCKus (Sep 10, 2020)

I’ve been an electrician since 2004 however I’m fairly inexperienced with standby generators. Setups with manual transfer switches and setups like that are no problem. It’s the automatic transfer switches I feel I could use some schooling on.

Scenario:

Meter main combo for the main service.
Automatic transfer switch.
Client wants the entire house covered by generator.

How I’ve done these in the past:

Main Breaker>Service side of ATS>ATS to lugs on main service bussing and to generator 

This setup up works and makes sense. The problem sometimes is just in the nuts and bolts of the job and either makes the job straight forward or a pain!

My questions:

How do I streamline these installs? 

Can I have a breaker off the main feed the ATS then have another breaker on the main backfeeding the panel off the load side of the ATS(generator power)? I’m assuming this could be dangerous unless the ATS has some sort of brains in it to open the circuit backfeeding the load side when on utility power.

NOW, is there an issue with doing the above if there is a normally open contactor on the breaker backfeeding the main from the ATS? So in theory it seems if the utility kicks on and opens that circuit everything would function as intended and safely. Is this something that SOUNDS logical but isn’t practical?

Other solution:
Everything I’m seeing on the internet seems to not be meter main combos. Does it just make more sense to just feed a sub(probably MLO) and move everything in there?

Lastly is there anyone that makes a panel setup for this scenario? All the generator ready panels I see have no meter socket.

Sorry for the long winded post and hopefully it’s not too confusing or somewhat makes sense.

Thank you in advance 

Ben


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## Kevin (Feb 14, 2017)

Welcome to the forum. 

Please take a few minutes to fill out your profile as per the user signup agreement. 

Thank you and enjoy your stay. 


P.S., I have never seen a meter main that is built to have an ATS installed, but there are some guys here that do generators way more often then myself and may know of some that I don't know about.


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## gpop (May 14, 2018)

The_RuCKus said:


> Can I have a breaker off the main feed the ATS then have another breaker on the main backfeeding the panel off the load side of the ATS(generator power)? I’m assuming this could be dangerous unless the ATS has some sort of brains in it to open the circuit backfeeding the load side when on utility power.


No. just because there is no power on the main it doesn't mean that its disconnected from the grid. You will simply backfeed the transformer where it will be transformed to around 7kv and fry the poco guy trying to fix the lines.



The_RuCKus said:


> NOW, is there an issue with doing the above if there is a normally open contactor on the breaker backfeeding the main from the ATS? So in theory it seems if the utility kicks on and opens that circuit everything would function as intended and safely. Is this something that SOUNDS logical but isn’t practical?


In industrial maybe but our breakers can be remotely opened and closed by a transfer controller. Way to expensive to even consider for a home owner.



The_RuCKus said:


> Other solution:
> Everything I’m seeing on the internet seems to not be meter main combos. Does it just make more sense to just feed a sub(probably MLO) and move everything in there?
> 
> Lastly is there anyone that makes a panel setup for this scenario? All the generator ready panels I see have no meter socket.
> ...


Generac is meant to be working on a service rated meter combo panel with built in transfer switch but its still waiting for approval.


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## johnnygreenham (Aug 25, 2020)

Could explain more what problem you are trying to work around with these, as I'm not sure what issue you are really having?
I don't install ATS's every week but generally the system is pretty simple.
If your ATS has a service disconnect (UL rated), you don't need a meter combination panel (with another main breaker) before it unless you need the breaker spaces to feed another outbuilding like a garage. Just a meter can is usually sufficient (but check with POCO). I've had some that don't care and some that I've argued with that we are just doubling up service disconnects and by NEC I'm covered. Sometimes space is an issue so the meter can only works well and its a lot cheaper. I still put combo's in sometimes if the scenario really benefits from it. The main breaker in the ATS now becomes your first service disconnect. Everything after this is now a sub panel. Thats usually the crux in a retro fit on older homes and requires the rest of the system to now comply, which it usually doesn't and requires a new 4 wire feed and Neutral/grounds split in panels. Generator feeds the backup input lugs and the Load lugs go to your panel feeding the branch circuits. Simple and done.


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## The_RuCKus (Sep 10, 2020)

johnnygreenham said:


> Could explain more what problem you are trying to work around with these, as I'm not sure what issue you are really having?
> I don't install ATS's every week but generally the system is pretty simple.
> If your ATS has a service disconnect (UL rated), you don't need a meter combination panel (with another main breaker) before it unless you need the breaker spaces to feed another outbuilding like a garage. Just a meter can is usually sufficient (but check with POCO). I've had some that don't care and some that I've argued with that we are just doubling up service disconnects and by NEC I'm covered. Sometimes space is an issue so the meter can only works well and its a lot cheaper. I still put combo's in sometimes if the scenario really benefits from it. The main breaker in the ATS now becomes your first service disconnect. Everything after this is now a sub panel. Thats usually the crux in a retro fit on older homes and requires the rest of the system to now comply, which it usually doesn't and requires a new 4 wire feed and Neutral/grounds split in panels. Generator feeds the backup input lugs and the Load lugs go to your panel feeding the branch circuits. Simple and done.


The problem is that in California most homes have a meter/main combo already installed. I’m mostly looking for a more efficient way of approaching this scenario(which is what I run into). I’m not trying to do a service change in every scenario, especially with things being so competitive.


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## The_RuCKus (Sep 10, 2020)

gpop said:


> In industrial maybe but our breakers can be remotely opened and closed by a transfer controller. Way to expensive to even consider for a home owner.
> .[/ QUOTE]
> 
> I’m not overly concerned with the cost of a contactor, I feel that’s non-factor for me. It makes sense to me that it would be a viable option BUT I’m curious how legit it would be and idk where I would get the answer(why I’m on here). I can’t see this being addressed in the NEC and asking an inspector or the utility would probably get me nowhere.
> ...


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## gpop (May 14, 2018)

The_RuCKus said:


> gpop said:
> 
> 
> > In industrial maybe but our breakers can be remotely opened and closed by a transfer controller. Way to expensive to even consider for a home owner.
> ...


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