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Discussion Starter · #1 ·
Has Anyone had any installations like this ?

So far what I’ve gathered is the solar controller may be able to determine the difference between utility and gen power if not a contractor may be required


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No go.

This is where you need a transfer panel. Even if you make one yourself by installing a normal subpanel and install an interlock on the main breaker of the subpanel and then move the essential circuits over to it.

The solar needs to be on the PoCo side of the transfer switch (which is the interlock if you instal one).
 

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My above post is assuming that your solar system is backfeeding a breaker. If the solar is connected to the service entrance conductors via a line side tap, then it is fine to install an interlock the normal way since the main breaker will isolate them.
 

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QUOTE - [ So far what I’ve gathered is the solar controller may be able to determine the difference between utility and gen power ]


YES !

You are correct, the invertors can tell if they are connected to either the grid or to an generator.

Back feeding a generator just doesn't work !
 

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Discussion Starter · #5 ·
My above post is assuming that your solar system is backfeeding a breaker. If the solar is connected to the service entrance conductors via a line side tap, then it is fine to install an interlock the normal way since the main breaker will isolate them.


It’s not back feeding the main panel

The meter socket has a Disconnect main breaker and the solar feeds into it


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Where, exactly, does the solar feed the house system?

A back fed breaker after the main?

Somewhere else?

Is there a panel inside that you can install the interlock on, isolating both the utility and the solar from the generator breaker and branch circuits?
 

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Discussion Starter · #7 ·
There is no breaker at the main panel for solar I only have pictures the customer sent me.

Just Trying to get familiar with this before I go look in person.

The panel only has 2 DP breakers 40A oven and 30A AC..

From the picture it goes to the meter socket and how solar exactly ties in I will have this answer when I go look closer


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Basically, you need to keep the solar on the same side of the interlock as the utility power, this way when you switch over the interlock both the utility and solar are isolated from the house electrical system and generator.
 

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What Hack said. Xfer switch between your meter box disconnect and the main panel, when utility and solar fail, Xfer isolates them and panel gets power from gen.
 

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What happens around here that I see often is the solar backfeeding the panel via a branch circuit breaker.

In that situation, you can't just install an interlock in the panel because the solar will still be feeding the house and backfeeding the generator, and vice versa.
 

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Looks like the solar ties into the meter main. If the panel doesn’t have a main then you’ll likely have to add one or change the panel to one that has one.
 

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Discussion Starter · #12 ·
Looks like the solar ties into the meter main. If the panel doesn’t have a main then you’ll likely have to add one or change the panel to one that has one.


Ya I will verify this but from the looks of exterior and panel Pictures I have the solar is at the meter main.

I will need to add a main breaker to the panel


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Discussion Starter · #13 ·
The panels tap the service conductors and don’t go inside to the panel



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Discussion Starter · #14 ·
Not familiar with solar setups. This is new to me.

How does this even work? Technically there are 2 power sources feeding the panel on the same lines.


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FWIW, those aren't the service conductors. Those are the load side of the main breaker, which means they are feeders.

If you add a main breaker to the panel inside, you can install an interlock on it and be compliant. The solar will be on the utility side of the interlocked breaker, which is what you want.
 

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Not familiar with solar setups. This is new to me.

How does this even work? Technically there are 2 power sources feeding the panel on the same lines.


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Yes, that's pretty much it. Two power sources meshed together by the inverter. The solar in that house and all the millions of other houses backfeed into the grid and help power it.
 

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Sorry to bump an old thread, but this one fits. Just looked at this situation today on a Siemens panel. Solar feed is a 2 pole breaker. I think this might work with 2 interlocks. Should be able to relocate the solar feed to ckts 2 and 4 and put the generator breaker in ckts 1 and 3. ecsbpk01 on the generator/solar breakers and ecsbpk03 with the normal tin snipping on the right side of it. Should work if the interlocks don't interfere with each other. Anybody tried this yet?
 
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