I found a similar post about this, but it doesn't quite answer my question. I'm in Texas, but I've read that California requires the AC disconnect to be located near the inverter. But I've also read that it is best to have the disconnect outside for easier access to first responders, etc. Since my inverter will be inside the garage, which is the best location for the disconnect, inside or outside? Note that the inverter is only a foot away from a door going outside and the disconnect would be maybe 4 feet away from that same door if it is mounted outside. In other words on opposite sides of the same wall with a door a few feet away.
AC disconnect location
- Thread starter lapsmith
- Start date
DIYrich
Solar Wizard
Both. You can more than one shutoff. Put one at the inverter, and one by the meter.
I hadn't thought of that. There is already a disconnect at the meter, but both are 300 feet away from the house/inverter so does it count as a disconnect? Does the disconnect have to be between the inverter and the main service panel, (assuming the inverter connects through a backfed breaker) or can it be between the meter and the main service panel?
If the inverter is connected via a line side tap, then it seems obvious that the disconnect has to be between the tap and the inverter. But I don't think it would be safe (or get approved) to rely on the disconnect I have that is 300 feet away.
I have both. Inside also has an indicator light that tells me the grid is available to the breaker (outside is breaker is closed) and the inside manual transfer switch shows if generator is available. Can’t have too many pretty lights.??
Yes, I will be net metering, but my meter and the existing disconnect seem like they are too far way to be of use. However, if the POCO or first responder knows where the meter is before arriving, they will pass right by it on my long driveway on the way to the house. They could then shut it down before getting to the house. But I can't imagine the fire fighters would have that information on every house in the area. I guess that's a good question to ask them.
As far as asking the POCO, they either don't respond or are extremely slow. And if they do, the answer is frequently to ask the AHJ, which is of no help since they are the only AHJ (I'm in an unincorporated area). Of course I want to meet the NEC, but I haven't been able to learn if it covers AC disconnect location.
DIYrich
Solar Wizard
BTW: the "disconnect" required for safety purposes is what causes the system to shutdown, and de-energize power lines, including solar panels connections. More of a shutdown than a disconnect switch. True disconnection is not required.
Are you sure about that?
Around here a physical manual lockable disconnect from grid is required by power co. A DC shutdown for the building is also required for fire responders, in my case with a big push button that will trigger RSD on the panels to de-energize the PV wires.
The disconnect switch does not shut down my inverter. It does notice that the grid is down and stops trying to send excess power back to the grid. The inverter/solar/batteries become my whole house UPS.
+1
I think that is the way it is here as well. At least as far as the lockable disconnect. I don't think I need RSD since my panels will be on a carport extension of the barn. But the Growatt inverter is Tigo-ready so I can add them later if necessary (plus they give some useful data about individual panels).
The Growatt also comes with a remote shutdown switch, but nothing in the manual or information I can find on line describes what it does. My guess is that it just shuts the inverter down and doesn't physically disconnect it from the PV or grid.
DIYrich
Solar Wizard
When needed, a true disconnect is at the meter. If not present, the utility will pull the meter to work on the line. That does not de-energize the system (goes into grid down mode). Multiple shutdowns is useful for safety purposes. When seconds matter, you don't want the fireman to run around looking for it.
zanydroid
Solar Wizard
I don’t need a lockable disconnect for an AC system in my AHJ/poco. There’s some mild language asking for it, but also an exemption you can practically automatically get.
So what folks in California with microinverters end up with is either shut off the main breaker to the house or a breaker related to the combiner box.
Properties I’ve seen solar on are tiny city lots so there’s not much running around needed. Still they require a system map next to the meter.
So what folks in California with microinverters end up with is either shut off the main breaker to the house or a breaker related to the combiner box.
Properties I’ve seen solar on are tiny city lots so there’s not much running around needed. Still they require a system map next to the meter.
I hear you. I am on 5 acres and the meter is not visible from the driveway. I wouldn't want them driving to the house and looking for it which is why I will put one at the house. The only question is inside next to the inverter or outside. I emailed the fire department and am waiting for their response.
Great idea. I will create a system map showing where everything is on the property and post it at several places.
