Generator Interlock for 400 amp residential

[hillbilly1]

Tell me how I am wrong

You are showing only one panel and one transferswitch.

 

[Ryancbell121]

You are showing only one panel and one transferswitch.

How do you not get the picture I drew? The 10/3 from the junction boxes go to the 2 pole breakers and the neutral/ground bar.

 

[Ryancbell121]

You are showing only one panel and one transferswitch.

Are you saying there’s going to be current on the service entrance conductors from the meter?

 

[Ryancbell121]

You are showing only one panel and one transferswitch.

Does this picture I attach explain what I fail to see and what you’re saying?

 

[Ryancbell121]

You are showing only one panel and one transferswitch.

 

[LarryFine]

One of my regrets about my own setup is that I went to 400 cause "I could" and the main reason I wish I didnt,, probably could have made it on 200 and would have made gen power a lot easier.

The fix to this is to put all of the generator loads in one panel.

 

[LarryFine]

There are two separate neutral topics being discussed here: bonding and paralleling.

1. Bonding; a generator's neutral should not be bonded when supplying a load whose neutral is bonded, but it should be bonded otherwise.

2. Paralleling; the two neutral conductors of a single inlet supplying two panels will inadvertently be interconnecting the two neutral buses.

 

[Ryancbell121]

There are two separate neutral topics being discussed here: bonding and paralleling.

1. Bonding; a generator's neutral should not be bonded when supplying a load whose neutral is bonded, but it should be bonded otherwise.

2. Paralleling; the two neutral conductors of a single inlet supplying two panels will inadvertently be interconnecting the two neutral buses.

And we want to avoid connecting the two neutral busses twice, correct? They are connected thru the meter enclosure already.

 

[Joethemechanic]

What if you only connected the neutral at one panel?

On second thought, that wouldn't be compliant

 

[Ryancbell121]

What if you only connected the neutral at one panel?

On second thought, that wouldn't be compliant

And have the current go back through the service entrance neutral conductor from the one 200 amp panel then into the second 200 amp panel then back on the generator feed neutral? I bet it would work but I’m sure its a violation.

 

[LarryFine]

As I said above, the best solution is to use only one panel for desired generator loads, IMO.

 

[Ryancbell121]

As I said above, the best solution is to use only one panel for desired generator loads, IMO.

Well then have one inlet for each panel and then you can use two generators, correct?

 

[Joethemechanic]

And have the current go back through the service entrance neutral conductor from the one 200 amp panel then into the second 200 amp panel then back on the generator feed neutral? I bet it would work but I’m sure its a violation.

Yeah no parallel path, but you would have a circuit with conductors in different cables/raceways/conduits

 

[LarryFine]

Well then have one inlet for each panel and then you can use two generators, correct?

Yes, they would function as two independent systems, as if they were two separate houses.

 

[Birken Vogt]

Another thing we have noticed is that these 320/400 amp services seldom calculate out to more than 200 amps of load on the Standard/Optional calc method, if it is a normal house.

So, abandon one 200A disco, run that existing 200A feed to a 125A breaker on the bus bar of the other 200A feed which is usually in the same can in California, and use a single transfer switch (or in your case interlock) to feed the whole mess, thus downgrading it to 200A but so what, it still works as intended.

 

[Joethemechanic]

I think these are kind of pricy. Not sure what the pocos say about them

GenerLink, Backup Generator | Global Power Products

 

[Ryancbell121]

I think these are kind of pricy. Not sure what the pocos say about them

View attachment 2566910

GenerLink, Backup Generator | Global Power Products

I’d have to ask the local utility company for one

 

[Joethemechanic]

Price: $1098.95

GenerLink MA23-S MA23-S | City Plumbing & Electric Supply

MA23-S | MA23-S | GenerLink | Global Power Products MA23-S GenerLink™ Automatic Transfer Switch, 200 VAC, 30 A with Surge Protection. 20ft cord & plug. 75Ka ..

www.cpesupply.com

Yeah, a bit more than an interlock kit

 

[hillbilly1]

Does this picture I attach explain what I fail to see and what you’re saying?

Correct, the generator neutral is parallel with the service neutrals to the panels.

 

[hillbilly1]

Well then have one inlet for each panel and then you can use two generators, correct?

Correct.