Generator interlock with Solar

[dcg9381]

Well, I think I want to put a generator on my shop. The shop powers my "pump house" - which provides water to our house and is essentially split at the power main. The house already has a generator with auto-start. The "simple" way to this perhaps, is just plug the water pump into a 240V generator, so I may be making it overly complicated, but I'd prefer if the shop had power overall.

Problem is, the shop has solar panels. Backfeeding a generator is a no-no. I've looked at control systems that work with generators from Fronius and they exist, but all they are going to do is reduce generator load in exchange for quite a bit of money and complication.

I think what I want to do is "interlock out" both my power main and solar at the panel. There is an interlock kit that is setup to work with "4 pole" breakers. I have 2 x 2 pole breakers, can I tie-bar these together (legally) - the main and the solar would be on the same bar?




It would like like this, via using this kit

 

[wyliesdiesels]

Not sure youll find a 4 position tie bar. what is the make and model on the panel and is the interlock youre looking at listed for use on that panel?

 

[Sumboodie]

Just turn the solar disconnect off.

 

[Neggy]

there is no way to safely do an interlock, even if you moved the solar to the right side of the panel and tied them horizontally, if the main overloaded and tried to pop, the tie bar might keep it from moving to the mid position

If you had a top of the panel main breaker there are UL/NEC approved interlocks

If you want to do it RIGHT use a transfer panel

 

[wyliesdiesels]

there is no way to safely do an interlock, even if you moved the solar to the right side of the panel and tied them horizontally, if the main overloaded and tried to pop, the tie bar might keep it from moving to the mid position

If you had a top of the panel main breaker there are UL/NEC approved interlocks

If you want to do it RIGHT use a transfer panel

Negative. Breakers can and do still trip even if their handle is immobilized. Breakers are designed this way on purpose.

Think of breakers for fire alarms that have a lock on the handle that prevents someone from turning them off...

 

[dcg9381]

Not sure youll find a 4 position tie bar. what is the make and model on the panel and is the interlock youre looking at listed for use on that panel?

I've seen (master) electricians use 10-12ga copper from romex as a tie bar. They doing it wrong?

Yes, the interlock shown above is what I was thinking about, as it locks out 4-breaker slots against the breaker immediately below it.
There are lots of options over on:

• https://interlockkit.com/ (the one referenced above is from this site)
• https://www.geninterlock.com/interlock-kits/eaton/

I can have one custom built (price unknown).

Panel details are below (Eaton):
Before you guys bust me on it - main bus is 125A. Feed is 90A, Max solar is 6KW, 25A... I'm under 125A.

 

[dcg9381]

If you had a top of the panel main breaker there are UL/NEC approved interlocks

If you want to do it RIGHT use a transfer panel

If I had a top main breaker, I still haven't seen an interlock designed for solar and a generator.
I don't see how a transfer panel would help unless it's dual lug at one feed (solar and main). It'd be easier to setup a main disconnect, setup a solar fused link, and feed the main disconnect - apparently that's how it is usually done.