Searching for AC Disconnect

[mnsweeps]

My neighbor has a separate box /switch marked AC DISCONNECT for his solar (not installed by Tesla).

I don't have that but do see a label which says "photovoltaic back-fed circuit breaker in main electrical panel is an AC disconnect per NEC 690.17". I have attached images of this label and other labels on my panels.

So is the 'SERVICE DISCONNECT' breaker in my main panel the AC DISCONNECT switch mentioned in the label?

 

[arnolddeleon]

What problem are you trying to solve?

 

[mnsweeps]

What problem are you trying to solve?

Locating the AC DISCONNECT.

 

[Vines]

Yes, that breaker labeled service disconnect is an AC Disconnect.

 

[mnsweeps]

Yes, that breaker labeled service disconnect is an AC Disconnect.

Thanks Vines. Thats all I need to know. I am very new to all this and learning a lot. Some people think questions are posted for the purpose of solving a problem which in this case is not but for self-learning.

 

[israndy]

I did my own install in Alameda CA and the city would not allow me to use the breaker as the AC disconnect, perhaps that because you can put a LOCK on the panel, but they made me buy and wire up a separate box with a big red throw lever to turn off the solar. Hilarious especially since all modern solar equipment turns off when the 240v power goes away.

 

[Vines]

I did my own install in Alameda CA and the city would not allow me to use the breaker as the AC disconnect, perhaps that because you can put a LOCK on the panel, but they made me buy and wire up a separate box with a big red throw lever to turn off the solar. Hilarious especially since all modern solar equipment turns off when the 240v power goes away.

AMP has its own requirements, which may be old news by now, but its one of the few cities around here with its own utility. CPAU does the same and requires a lockable AC Disconnect for every job regardless.

 

[BrettS]

Keep in mind that your service disconnect and your neighbor’s AC disconnect perform different functions.

Your neighbor’s AC disconnect will disconnect his inverters from his house and shut down the solar system.

Your service disconnect will disconnect your house from the grid, but your house will keep running on your powerwalls and solar.

I think the reason that @arnolddeleon asked for clarification was to try to figure out exactly what you were looking to disconnect. If you want something that will just disconnect your inverters and shut off your solar system then there will be a different breaker for that.

 

[Vines]

Thanks Vines. Thats all I need to know. I am very new to all this and learning a lot. Some people think questions are posted for the purpose of solving a problem which in this case is not but for self-learning.

No problem. Brett beat me to the follow up info, I was going to post the same.

If your PV and PW breakers are both in the Gateway 2 internal panelboard, then that will be the location for first responders to shut down in an emergency all generation sources.

 

[sorka]

I did my own install in Alameda CA and the city would not allow me to use the breaker as the AC disconnect, perhaps that because you can put a LOCK on the panel, but they made me buy and wire up a separate box with a big red throw lever to turn off the solar. Hilarious especially since all modern solar equipment turns off when the 240v power goes away.

Is your inverter within direct line of site of your AC breaker? If not, then you would have needed a disconnect switch.

 

[Vines]

My neighbor has a separate box /switch marked AC DISCONNECT for his solar (not installed by Tesla).

I don't have that but do see a label which says "photovoltaic back-fed circuit breaker in main electrical panel is an AC disconnect per NEC 690.17". I have attached images of this label and other labels on my panels.

So is the 'SERVICE DISCONNECT' breaker in my main panel the AC DISCONNECT switch mentioned in the label?

Speaking on labels, what rookie printed those plastic plaques? Here's something fun I printed for a co-worker, as a tester.

Perfect for 2020 eh?

 

[mnsweeps]

Keep in mind that your service disconnect and your neighbor’s AC disconnect perform different functions.

Your neighbor’s AC disconnect will disconnect his inverters from his house and shut down the solar system.

Your service disconnect will disconnect your house from the grid, but your house will keep running on your powerwalls and solar.

I think the reason that @arnolddeleon asked for clarification was to try to figure out exactly what you were looking to disconnect. If you want something that will just disconnect your inverters and shut off your solar system then there will be a different breaker for that.

Good points @BrettS . If you look at photos you will notice the SERVICE DISCONNECT has a BACKUP LOAD CENTER label near it. And inside the Backup load center, I have breakers for backed up load and Powerwalls and Solar PV. My understanding is if I turn off the service disconnect breaker, it would turn off powerwall, Solar PV and backed up loads . I have attached pictures of backed up load panel in this post. So looks like the Service Disconnect in my case acts as a AC DISCONNECT as it turns off solar/powerwall?

And there is a MAIN DISCONNECT in the main panel which I think turns off everything from the grid.

This is all my understanding. Please correct me if I am wrong.

 

[BrettS]

Good points @BrettS . If you look at photos you will notice the SERVICE DISCONNECT has a BACKUP LOAD CENTER label near it. And inside the Backup load center, I have breakers for backed up load and Powerwalls and Solar PV. My understanding is if I turn off the service disconnect breaker, it would turn off powerwall, Solar PV and backed up loads . I have attached pictures of backed up load panel in this post. So looks like the Service Disconnect in my case acts as a AC DISCONNECT as it turns off solar/powerwall?

And there is a MAIN DISCONNECT in the main panel which I think turns off everything from the grid.

This is all my understanding. Please correct me if I am wrong.

That is wrong. To turn off the solar you would need to turn off the breaker labeled “Solar PV Breaker” and to turn off the powerwalls you would need to turn off the breaker labeled “Energy Storage System Disconnect”.

As I said earlier, turning off the Service Disconnect will disconnect your system from the grid, but the powerwalls and solar will continue to power your backed up loads. However, your non backed up loads will still be powered from the grid.

Turning off the Main Disconnect will also disconnect your system from the grid, but again, the powerwalls and solar will continue to power your backed up loads. In this case, however, your non backed up loads will no longer be powered at all.

 

[arnolddeleon]

That is wrong. To turn off the solar you would need to turn off the breaker labeled “Solar PV Breaker” and to turn off the powerwalls you would need to turn off the breaker labeled “Energy Storage System Disconnect”.

As I said earlier, turning off the Service Disconnect will disconnect your system from the grid, but the powerwalls and solar will continue to power your backed up loads. However, your non backed up loads will still be powered from the grid.

Turning off the Main Disconnect will also disconnect your system from the grid, but again, the powerwalls and solar will continue to power your backed up loads. In this case, however, your non backed up loads will no longer be powered at all.

Hey I thought the OP question was already answered ;-)

I see that @Vines cutely answered that it was "an AC Disconnect" and cleverly dodged the possible different result depending on the objective.

Let me list a few questions that might been asked:

How do I "shutdown" the solar system? (Solar PV breaker)
How do I "shutdown" the Powerwalls? (Energy Storage System Breaker)
How do I prevent power flowing back to the grid? (Main Disconnect or Service Disconnect, plus other options)
How do I shutdown all the power sources to the house? (If the question is really all then minimally it is the Energy Storage breaker and the main breaker)

I'm the utility, how do I lock out the system? (pull the meter)

 

[Vines]

I usually differentiate by the following language:
PV RAPID SHUTDOWN
BATTERY DISCONNECT
BLADED LOCKABLE AC DISCONNECT
BATTERY REMOTE DISCONNECT

For the backup systems we install, any individual PV disconnect is most often also rapid shutdown, but I will pick the path with the least number of steps or switches to activate.

Depending on your SLD, you could have one or more switch, button or breaker that you need to activate to shutdown the generation facility.

It was intentional that I didn't give more explanation than was asked for, as the OP didn't seem to ask for that yet.

Also pulling the meter wont lock a PV system out, and will leave exposed unprotected conductors so is not a safe way for a utility to lockout a home except in an emergency.