Generator interlock location?

[Dave Nelson]

Having a new home built in another state, and wanted a generator interlock on the panel cover similar to what I have now. I currently have a 5500 portable Generac and a manual interlock on the cover on the Square D cover, have used this set up several times with no issues.
New home has a 200 amp CH panel with no main breaker, outside there is a Eaton combination meter/panel. When I was there several weeks ago the panels were not installed at that time. I did a walk thru with one of the electricians for the rough in, while I was there I gave him the Reliant outdoor generator receptacle and told him to run the 10/3 to the panel and terminate on the bottom left hand 2 pole position thinking there would be a main in the bottom of the panel.
Fast forward now the panel and combination meter/panel installed and I find out no main breaker in house panel, and in the combination panel there are three 2 pole breakers, one for range, one for HVAC and one marked sub panel for the house.
My question is can I take the 10/3 from the house panel and extend it to the combination panel and put some type of interlock on the sub panel breaker?

 

[wyliesdiesels]

What would the interlock be locking out? There is no point on the main since theres no main breaker. And installing the generator breaker in the main would energized the whole panel and backfeed the grid

Only place interlock can go is on the subpanel IF it has a main breaker.

I wouldve discussed what type of main youre getting before the contractor put it in. Now youre stuck...

 

[slow]

Can you add a main breaker to the panel?

 

[Dave Nelson]

My only other thought to use the generator is I would have to go out to the meter/combination panel and shut off the breakers in there then use the generator 30 amp 2 pole breaker I first intended to use to feed the house panel.

 

[wyliesdiesels]

My only other thought to use the generator is I would have to go out to the meter/combination panel and shut off the breakers in there then use the generator 30 amp 2 pole breaker I first intended to use to feed the house panel.

Where would the 30a breaker go? In the main panel? If so, then you would be back feeding the grid.

The only way to make this work for your current setup, is by putting the gen breaker and interlock in the subpanel.

 

[Dave Nelson]

Just to clarify, they are calling the house panel the sub panel as it is fed from a breaker in the meter combination panel. I will look into moving the generator breaker out to that panel with some type of interlock.

 

[wyliesdiesels]

Yes any panel after the main is a subpanel and must have isolated neutral and 4-wire feeder. Inside subpanels are typical termed load centers.

But since there is no single main breaker in your meter main, the only place a generator breaker and interlock can go is in the house subpanel.

 

[Dave Nelson]

Yes, but because there is no main in the house/sub panel how would a interlock be installed?

 

[wyliesdiesels]

Yes, but because there is no main in the house/sub panel how would a interlock be installed?

Oh i missed that there is no main in the subpanel. Youre SOL then.

Can the lectrician put in a main breaker in the subpanel?

Otherwise you will need to do a transfer switch between main and sub or a multibranch breaker transfer switch.

 

[PCustoms]

Why not wire the whole place up with an ATS?

 

[wyliesdiesels]

Why not wire the whole place up with an ATS?

An ATS gets stupid expensive quick here.

Generator needs to be sized for the entire load, OR load shedding modules would need to be utilized. Expensive either way you slice it.

A manual transfer switch is way cheaper

 

[PCustoms]

An ATS gets stupid expensive quick here.

Generator needs to be sized for the entire load, OR load shedding modules would need to be utilized. Expensive either way you slice it.

A manual transfer switch is way cheaper

The guy is building a brand new house, seems like the time to do it (either way). Can the ATS be put in without the generator?

 

[Dave Nelson]

Ok, so in theory if I were to turn off the three breakers in the meter/combination panel (one is marked sub panel) and use the 30 amp 2 pole breaker in the house/sub panel for the generator feed wouldn't this eliminate the possibly of back feeding the grid?

 

[PCustoms]

Ok, so in theory if I were to turn off the three breakers in the meter/combination panel (one is marked sub panel) and use the 30 amp 2 pole breaker in the house/sub panel for the generator feed wouldn't this eliminate the possibly of back feeding the grid?

No, because nothing is preventing the 3 breakers from being turned back on.

 

[wyliesdiesels]

Yeah turning off the breaker feeding the house subpanel would however that is not good enough because it can easily be turned back on. Also, what if you forget one day when youre in a hurry? What if youre not hooking it up and someone else is and forgets.

Not a good idea and most AHJs will not pass something like that if they see it.

You said this is a new house. Do it correctly.

Why cant you ask the electrician to add a main breaker to the subpanel?

 

[83VillageRepair]

A generlink ats that installs under the meter would work here if your utility allows it and your generator is small enough. I think they have a 30 and a 50. Pretty idiot proof and code compliant.

http://www.generlink.com/

 

[Dave Nelson]

A generlink ats that installs under the meter would work here if your utility allows it and your generator is small enough. I think they have a 30 and a 50. Pretty idiot proof and code compliant.

http://www.generlink.com/

That is a good alternative if allowed by the utility.

 

[Dave Nelson]

Yeah turning off the breaker feeding the house subpanel would however that is not good enough because it can easily be turned back on. Also, what if you forget one day when youre in a hurry? What if youre not hooking it up and someone else is and forgets.

Not a good idea and most AHJs will not pass something like that if they see it.

You said this is a new house. Do it correctly.

Why cant you ask the electrician to add a main breaker to the subpanel?

Going down to home next week to meet with contractor, will see if main breaker can be add to panel.

 

[wyliesdiesels]

Going down to home next week to meet with contractor, will see if main breaker can be add to panel.

Should be able to do a backfed main if there is not a provision for a bolt on main.

 

[theoldwizard1]

New home has a 200 amp CH panel with no main breaker, outside there is a Eaton combination meter/panel.

The combo panel is your first disconnect. Interlock should go there.

 

[theoldwizard1]

An ATS gets stupid expensive quick here.

Generator needs to be sized for the entire load, OR load shedding modules would need to be utilized. Expensive either way you slice it.

A manual transfer switch is way cheaper

Nailed it !

 

[wyliesdiesels]

The combo panel is your first disconnect. Interlock should go there.

Better read a little more carefully.

Putting the interlock and generator breaker on the combination meter main, will backfeed the grid. There is NO main disconnect as its a multi-space main service panel.

 

[Dave Nelson]

Going to install a main breaker in the house/sub panel. The breaker that feeds that panel from the meter/combination is 90 amp 2 pole. What size main breaker should be installed in sub/house panel?

 

[jlv03]

The breaker in the sub/house panel can be the same size or larger. Its purpose isn't to act as a breaker but rather a mechanical disconnect. A 100A main breaker is probably the easiest and most common breaker you'll find for this use, so I would use that. The outside 90A is the breaker providing the overcurrent protection in this case.

 

[Dave Nelson]

The breaker in the sub/house panel can be the same size or larger. Its purpose isn't to act as a breaker but rather a mechanical disconnect. A 100A main breaker is probably the easiest and most common breaker you'll find for this use, so I would use that. The outside 90A is the breaker providing the overcurrent protection in this case.

Thanks for the reply, going with the 100 amp main.

 

[Metallitubby]

Posting these for Dave

 

[Dave Nelson]

That is the water line trench in the first pic, waiting for inspector.

 

[wes73]

What about something like this? https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-MA23-N/301961623

EDIT - No personal experience, just ran across this while looking at interlocks.

 

[slow]

What about something like this? https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-MA23-N/301961623

EDIT - No personal experience, just ran across this while looking at interlocks.

Many power companies will not allow that device, but it is a cool idea, but a premium price.

 

[Dave Nelson]

I'm pretty sure Duke Energy does not allow those.

 

[wyliesdiesels]

What about something like this? https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-MA23-N/301961623

EDIT - No personal experience, just ran across this while looking at interlocks.

Depends on PoCo. need their blessing to install and use it.

Most do not like them