PV Disconnect Location (microinverters)

[ohmti787]

Here's my dumb question: Article 690.15(A) states that the PV disconnect needs to be within 10' of the equipment. So for systems with microinverters, is the combiner box/panel considered the "equipment"? If so, then would the string breakers inside the CB be considered a disconnecting means "within the equipment"?

 

[ggunn]

Here's my dumb question: Article 690.15(A) states that the PV disconnect needs to be within 10' of the equipment. So for systems with microinverters, is the combiner box/panel considered the "equipment"? If so, then would the string breakers inside the CB be considered a disconnecting means "within the equipment"?

I forget the reference, but MC4 connectors are considered to be disconnecting means by the NEC.

 

[Designer101]

Here's my dumb question: Article 690.15(A) states that the PV disconnect needs to be within 10' of the equipment. So for systems with microinverters, is the combiner box/panel considered the "equipment"? If so, then would the string breakers inside the CB be considered a disconnecting means "within the equipment"?

yes the circuit breaker in combiner panel is means of Disconnect.(690.12 (E))

I forget the reference, but MC4 connectors are considered to be disconnecting means by the NEC.

690.33 (d)

 

[ohmti787]

I mean, I always put a disconnect right after the CB, because utilities like to have that knife blade almost all the time here in FL. But just to make sure, the 10' requirement would be between the disconnect and the CB, correct?

So in this particular case, my AC disconnect, the CB and the meter are all right next to each other. So this inspector just hit me with that article (690.15(A)) because I did a supply side tap inside the MSP which is on the opposite side of the wall ("back to back") from the meter. Am I missing something here?

 

[jaggedben]

I forget the reference, but MC4 connectors are considered to be disconnecting means by the NEC.

These sections have been rearranged every code cycle so one really needs the code cycle mentioned to give an exact reference. But what you say has been correct throughout. The AC cable plug may also qualify.

 

[ohmti787]

So just to make sure: when the code says the "equipment", it's referring to the inverter, not the main service panel, correct?

 

[mtnelect]

I don't install solar, but who removes and reinstalls the solar panels and related equipment when a roof is replaced. Also, is a permit required to reinstall ?

 

[jaggedben]

So just to make sure: when the code says the "equipment", it's referring to the inverter, not the main service panel, correct?

An 'equipment disconnecting means' is required for circuits of more than 30A. For lower amperages an 'isolating device' can be used. Different parts of 690.15 lay out the exact requirements for each of those, for the purposes of 690. For microinverters, the connectors typically meet the requirements for isolating devices and an equipment disconnecting means is not required.

The exact code references have changed in each of the last few code cycles. But read 690.15 and maybe 690.13 in their entirety.

 

[lifeonezmode]

I mean, I always put a disconnect right after the CB, because utilities like to have that knife blade almost all the time here in FL. But just to make sure, the 10' requirement would be between the disconnect and the CB, correct?

So in this particular case, my AC disconnect, the CB and the meter are all right next to each other. So this inspector just hit me with that article (690.15(A)) because I did a supply side tap inside the MSP which is on the opposite side of the wall ("back to back") from the meter. Am I missing something here?

No i agree that's allowed 690 just says your disconnect means should be readily accessible and within sight of equipment. Also not on a different level

 

[ohmti787]

Sorry I'm circling back on this. But the MC4 connectors would only isolate the PV from the Combiner box. However the busbar in the CB would still be hot. So technically I'm not isolating the PV equipment from the utility by only disconnecting the MC4 connectors, or even by shutting down the breaker in the CB. Pretty sure I still need that disconnecting means between the equipment (CB) and the grid. Question is where exactly? Thanks for all your insights btw

 

[ohmti787]

for example: is this installation code compliant?

 

[jaggedben]

Sorry I'm circling back on this. But the MC4 connectors would only isolate the PV from the Combiner box. However the busbar in the CB would still be hot. So technically I'm not isolating the PV equipment from the utility by only disconnecting the MC4 connectors, or even by shutting down the breaker in the CB. Pretty sure I still need that disconnecting means between the equipment (CB) and the grid. Question is where exactly? Thanks for all your insights btw

The MC4 is an isolating device for the module and for the DC side of the microinverter (or optimizer, etc.).

You do need a disconnecting means between the combiner and the grid but that can be the circuit breaker in the panel you are tying into. I think it is over reaching to require an additional disconnecting means at the combiner; the combiner is basically a subpanel. It is not one of the types of equipment requiring isolation in 690.15 (2023 NEC).

 

[jaggedben]

for example: is this installation code compliant?

View attachment 2570066

Yes, but the AC disconnect in the foreground is not required by the NEC. (Well, not unless it's something less usual like a fused disco for a load-side or line side tap.)

 

[ohmti787]

The MC4 is an isolating device for the module and for the DC side of the microinverter (or optimizer, etc.).

You do need a disconnecting means between the combiner and the grid but that can be the circuit breaker in the panel you are tying into. I think it is over reaching to require an additional disconnecting means at the combiner; the combiner is basically a subpanel. It is not one of the types of equipment requiring isolation in 690.15 (2023 NEC).

Well, say I don't have the disconnect outside, then I would have to go all the way to the MSP which is inside, to shut down the PV breaker and be able to do work on the CB. I think that's the whole purpose of the 10' requirement, whether there's an additional disconnect or not.

 

[jaggedben]

Well, say I don't have the disconnect outside, then I would have to go all the way to the MSP which is inside, to shut down the PV breaker and be able to do work on the CB.

That's the situation for any subpanel and is totally allowed by the NEC for subpanels. What's different here?
I'm not saying it's bad to have a disconnect next to the combiner for this purpose, just that it's not code required.

I think that's the whole purpose of the 10' requirement, whether there's an additional disconnect or not.

What 10ft requirement? Code section?

 

[ohmti787]

690.15(A)

 

[jaggedben]

690.15(A)

Which code cycle? I don't see that in 2023.

 

[jaggedben]

Okay it looks like you are looking at either 2017 or 2020. (The specific 10ft requirement appears to have been removed in the 2023 NEC). That requirement for an isolating device applies to:

Ac PV modules, fuses, dc-to-dc converters, inverters, and charge controllers.

The Enphase combiner is none of those things.

 

[ohmti787]

i'm sorry, it is the 2020 code.

I agree that the combiner box is none of those things. however, according to Enphase engineers, that's how they "recommend" it to be interpreted, since the combiner box is the closest thing they have to a central component like say a string inverter.

 

[Designer101]

i'm sorry, it is the 2020 code.

I agree that the combiner box is none of those things. however, according to Enphase engineers, that's how they "recommend" it to be interpreted, since the combiner box is the closest thing they have to a central component like say a string inverter.

i doubt if enphase engineers says so but i might be wrong. There are so many people in the market to behave like they know but actually they dont, its not required by code to have seperate AC disconnect for load side connection , line side connection is whole different strory, When there is already a AC combiner box but your local AHJ and especially Utilty enforces those AC disconnects. Buttom line is there is no harm in keeping those Ac disconnects betwen utilty point of connection and combiner Box, but its not required by code.