APSystems installation

[Ampster]

The NEC requirement is the maximum allowed. As a practical matter it probably depends on the individual device if it is less than that or not. If Pir8radio is referring to his inverter then that is where one would find that information.

[NewBostonConst]

The inverter shutdown happens in 120ms adjustable down to 60ms which is almost as fast as a typical relay drop-out time anyway, also there is no neutral on the micro inverters, just split phase and ground.

Per NEC 2014/2017 690.12 Rapid Shutdown can be up to 10 seconds or 30 seconds depending on the design.

I don't find any document that states the times you are quoting....If you are correct then I agree a relay is not needed.

[Pir8radio]

Pir8radio, I believe you stated you were cutting off the factory connector so you will likely be using a junction box. If you run 4 conductor cable and your plug is 4 conductor (Ground, Common, L1, L2)

So, if you place a dpdt relay in the box with a 120vac coil you can connect the relay coil between the common and L1, and then L1/L2 wires are connected to the NO relay contacts.

So when the plug is attached to power, the relay is energized and power flows to and from the micro inverter. Then when the plug is unplugged the neutral connection is lost, opening the relay and taking power off the other terminals of the plug. So rapid shutdown has its time to power down with no power on the plug connectors. So all is safe.

Hope this helps and makes your setup safer. This is how I did mine a while back, though I have not had the chance to unplugged under load and test for power. Mybad....

The inverter shutdown happens in 120ms adjustable down to 60ms which is almost as fast as a typical relay drop-out time anyway, also there is no neutral on the micro inverters, just split phase and ground.

[Pir8radio]

Except, as @Pir8radio said, "what do you think a branch or bus cable is that they sell for micro inverters ?" IOW, there's gonna be connectors. Thing is, though I haven't yet seen one of the APSystems connectors in person, they don't appear as though they have bare-metal prongs.

They do not have bare prongs you are correct, but like i said a selling point for the ap systems bus plugs is that those plugs ARE the AC DISCONNECT required by nec, thats why they shield the prongs on both ends, due to ac disconnect requirements in nec. I have ac disconnect breakers in sight of the inverter so nec is met, not worried about using my plugs as "AC Disconnects" for the solar part of nec.

[SunEagle]

Generally, when someone plugs into an outlet, the outlet is on a shared circuit. If your outlets are individually wired back to a breaker rated for the wire gauge in use, that's safer, but you have taken a compliant Micro Inverter and downgraded it to a Plug-In inverter which, because they are often plugged in to branch circuits, is not permissible. I don't know the subtleties of the code regarding using a dedicated unique outlet & matching plug instead of a hardwire & disconnect.

Actually some AHJ will allow a plug on a dedicated Circuit breaker to back feed from solar. That usually means some type of non typical plug & receptacle that keeps a standard plug from being connected to the receptacle.

Having a quick "plug & play" system works if you can get the AHJ to understand it is safe and "fool proof" from being hacked by a non electrical educated person. Although having a hard wired terminal box for the pv input power seems to streamline the process.

[NewBostonConst]

Pir8radio, I believe you stated you were cutting off the factory connector so you will likely be using a junction box. If you run 4 conductor cable and your plug is 4 conductor (Ground, Common, L1, L2)

So, if you place a dpdt relay in the box with a 120vac coil you can connect the relay coil between the common and L1, and then L1/L2 wires are connected to the NO relay contacts.

So when the plug is attached to power, the relay is energized and power flows to and from the micro inverter. Then when the plug is unplugged the neutral connection is lost, opening the relay and taking power off the other terminals of the plug. So rapid shutdown has its time to power down with no power on the plug connectors. So all is safe.

Hope this helps and makes your setup safer. This is how I did mine a while back, though I have not had the chance to unplugged under load and test for power. Mybad....

[bob-n]

Right. There is no exposed metal, either on the male or female of the APsystems connector.

[RShackleford]

Yes, I agree. I don't even know why someone would add another point of failure in an outdoor environment like that.

Except, as @Pir8radio said, "what do you think a branch or bus cable is that they sell for micro inverters ?" IOW, there's gonna be connectors. Thing is, though I haven't yet seen one of the APSystems connectors in person, they don't appear as though they have bare-metal prongs.

[RShackleford]

It really comes down to what the AHJ determines what is allowed or not.

Yep. I asked my AHJ if I needed fence around my ground-mount system (which can have voltages of up to 600vdc in a string) and he said "no" and I asked what keeps someone from grabbing those wires and he said "common sense". I guess as far as NEC, 599v is no different than 240v, and maybe having un-covered 240vac Romex would be ok in such a situation ...

[Ampster]

Good point. I still suspect an inspector would be unhappy.

Yes, I agree. I don't even know why someone would add another point of failure in an outdoor environment like that.

[Pir8radio]

Well, it sounds like you have actually planned the system and if the inspector accepts it, you win.

I’m sorry If I came off as argumentative. I’m seriously looking for a hole in my logic. I wasn’t trying to argue or “win”.
inspector approved but that’s not saying much where I live. I want it to be safe regardless of what anyone said is good.

[Mike90250]

Well, it sounds like you have actually planned the system and if the inspector accepts it, you win.

[Pir8radio]

Generally, when someone plugs into an outlet, the outlet is on a shared circuit. If your outlets are individually wired back to a breaker rated for the wire gauge in use, that's safer, but you have taken a compliant Micro Inverter and downgraded it to a Plug-In inverter which, because they are often plugged in to branch circuits, is not permissible. I don't know the subtleties of the code regarding using a dedicated unique outlet & matching plug instead of a hardwire & disconnect.

Again no basis or code example, what do you think a branch or bus cable is that they sell for micro inverters. I have the same thing but with standardized connections. I have three 240v outlets on each of my 15 amp circuits, with 12ga wire. Three inverters per circuit.

Code only requires a unique receptacles compared to what is in use by other electrical systems on the premises. I have no 240v outlets in use on my premises. 690.33 (A)

[Mike90250]

no, outlets. 240v outdoor outlets, replaced the micro inverter plugs with 240v plugs. Just like any other outdoor outlet. Covered with an in use cover.

Generally, when someone plugs into an outlet, the outlet is on a shared circuit. If your outlets are individually wired back to a breaker rated for the wire gauge in use, that's safer, but you have taken a compliant Micro Inverter and downgraded it to a Plug-In inverter which, because they are often plugged in to branch circuits, is not permissible. I don't know the subtleties of the code regarding using a dedicated unique outlet & matching plug instead of a hardwire & disconnect.

[Pir8radio]

But as you know the NEC is sometimes funny to figure out what it means.

Try the NESC which we follow lol...

And I do understand the points made, I do appreciate the input. Like I said above too, the NEC allows exposure to energized conductors if you are "qualified persons" and as long as you can not "accidentally" contact energized conductors. You would have to climb up to open my while-in-use cover, unplug, then touch the terminals, nothing accidental about that (again, all assuming UL1741 has failed here, which if it did, I would be putting linemen at risk with over 7kv at the pole from back-feeding through the transformer, a bigger issue which 1741 is there to protect against).

I hold personal safety and system stability dear to my heart, especially when 3.5 million customers, and 8k+ employees depend on my designs being safe, I guess I got offended by the incorrect statement "And don't even think of suggesting anyone else follow your unsafe choices".