Interconnecting into a Square D Meter Socket

[electrofelon]

Lucky you.

For some of the utilities I work with they publish example electrical drawings of how to interconnect commercial PV within their jurisdiction. If you submit something else, it does not matter what it is; they will reject it. They will not cite code or return any comment other than to say that it doesn't conform to their specifications. Their way or the highway; maybe it's a Texas thing.

I guess I am still unclear and curious where the line is drawn or what differentiates a "regular" load side connection from my post #18 proposed load side connection. As Wayne and I said, it seems like they would have to have some oddly specific wording like "service entrance conductor sets serving only PV loads shall be considered line side connections" or "if conductors are addded the new conductors shall be considered to supplying the PV system". It seems like "messing with" the conductors is what they dont like.

When I submit drawings of my method to the state agency that review the plans and the utility, I clearly identify how I am qualifying the conductors. For example I will circle the two conductor sets coming off the meter and say "two sets of service entrance conductors per 230.40 exception #3: One set for house and second set for ground mount array structure.

 

[ggunn]

Are you saying that their design manual has rules 1-10 listed, and an example figure that complies with rules 1-10, but also happens to have features 11-15 never mentioned in the text, and the POCO treats features 11-15 as mandatory? If so, that's clearly wrong-headed.

Unless things work differently in Texas, a rejection based on non-compliance with features 11-15 would not stand up if challenged. But it may not be worth taking to a higher POCO authority or the PUC, obviously the trouble may exceed the benefit.

Cheers, Wayne

It can be worse than that. The inspector may decide on the spot after the system is built that he doesn't like something that isn't documented at all and fail us for that. It doesn't happen that often or in that many jurisdictions (it's mostly one guy in particular), but it does happen.

 

[electrofelon]

It can be worse than that. The inspector may decide on the spot after the system is built that he doesn't like something that isn't documented at all and fail us for that. It doesn't happen that often or in that many jurisdictions (it's mostly one guy in particular), but it does happen.

So would you mind considering this situation and giving my your thoughts? So say you have a perspective PV site and there is a 400A service with 2 200A MB panels. Lets say only one of the panels has loads in it. Barring situations where the POCO has very specific PV interconnection requirements like its own service or meter for all PV, I assume you could interconnect your solar with backfed breakers into the unused 200A panel yes? Using the "sum of all OCPD's except the OCPD protecting the busbar" rule yes? So is it conceivable that you could have a POCO that allows that, but if that second panel didnt exist and you wanted to add it (ultimately ending up with the same thing as the 'it already exists' scenario) as part of the PV then they wouldnt allow it?

 

[wwhitney]

The inspector may decide on the spot after the system is built that he doesn't like something that isn't documented at all and fail us for that.

That's a terrible thing to have to deal with--it's clearly wrong and wouldn't hold up in court. But of course the trouble of contesting it probably exceeds the benefit of doing so.

Since such behavior is clearly the exception, I don't think it's informative for general discussions about the issues in this thread.

Cheers, Wayne

 

[electrofelon]

.....Also I would appreciate it if @pv_n00b could respond to his experience with the scenario in post #43

 

[wwhitney]

If it’s in a can where our meter equipment is located it will be approved by us or . . .

So if a residential customer has an overhead service with a standalone meter can on the house, and wants to run a second set of service entrance conductors to an outbuilding, would your company (utility) allow the splice to be in the meter can (on the load side of meter)? Either with IPCs or with a factory lug kit or with a product like kwired showed in post #34?

Now if the splice isn't for an outbuilding service, but is instead for a second service disconnect on the house that will have PV behind it, does the answer change?

I would suggest that if the answer is different, that's illogical (unless there's some technical reason I'm missing?) Obviously your company can have illogical rules, but knowledgeable customers will still dislike it.

Cheers, Wayne

 

[electrofelon]

So if a residential customer has an overhead service with a standalone meter can on the house, and wants to run a second set of service entrance conductors to an outbuilding, would your company (utility) allow the splice to be in the meter can (on the load side of meter)? Either with IPCs or with a factory lug kit or with a product like kwired showed in post #34?

Now if the splice isn't for an outbuilding service, but is instead for a second service disconnect on the house that will have PV behind it, does the answer change?

I would suggest that if the answer is different, that's illogical (unless there's some technical reason I'm missing?) Obviously your company can have illogical rules, but knowledgeable customers will still dislike it.

Cheers, Wayne

......and if there are no's, does the use of a class 320 Meter socket that is "intended" for two load side connections change anything?

As I think I stated before, I interconnect pretty much all my ground mounts using 230.40 exception 3, and I pretty much always replace the existing meter socket with a class 320 socket. The 320 socket isn't specifically needed for capacity purposes, it's just nice for the space and the convenient load lugs. It's probably a couple hundred bucks more than adding a splice box below the meter, but it looks cleaner and typically these conductors are larger so I wouldn't even want to try to bring them into a 200 amp meter socket.

 

[ggunn]

So would you mind considering this situation and giving my your thoughts? So say you have a perspective PV site and there is a 400A service with 2 200A MB panels. Lets say only one of the panels has loads in it. Barring situations where the POCO has very specific PV interconnection requirements like its own service or meter for all PV, I assume you could interconnect your solar with backfed breakers into the unused 200A panel yes? Using the "sum of all OCPD's except the OCPD protecting the busbar" rule yes? So is it conceivable that you could have a POCO that allows that, but if that second panel didnt exist and you wanted to add it (ultimately ending up with the same thing as the 'it already exists' scenario) as part of the PV then they wouldnt allow it?

I don't know the answer, and I don't know that all POCOs would answer it the same way. We have encountered similar existing services where the two panels connected to the meter were feedthrough 200A panels with no loads (cheaper than discos, maybe?) and they have mostly been in rural areas and usually so far away from any buildings that we don't land our PV conductors in them. We interconnect on the load side of one of them at a building and put a placard on it saying NO LOADS.

Two things, though. I have never encountered a 400A service that didn't already have two connections to it, and the ones I have dealt with were in rural areas where the POCO is not so picky. One more thing: these have all been residential systems where we don't have to go through a plan review.

 

[electrofelon]

I don't know the answer, and I don't know that all POCOs would answer it the same way. We have encountered similar existing services where the two panels connected to the meter were feedthrough 200A panels with no loads (cheaper than discos, maybe?) and they have mostly been in rural areas and usually so far away from any buildings that we don't land our PV conductors in them. We interconnect on the load side of one of them at a building and put a placard on it saying NO LOADS.

Two things, though. I have never encountered a 400A service that didn't already have two connections to it, and the ones I have dealt with were in rural areas where the POCO is not so picky. One more thing: these have all been residential systems where we don't have to go through a plan review.

"So Mr Gunn, just to be clear, would you say the scenario in post #43, with the two existing 200 amp sets and panels, that that is a pretty straightforward load side connection where you could back feed about 160 amps?"

"Objection your honor he's leading the witness!"

Judge: "You may answer the question..."

 

[ggunn]

"So Mr Gunn, just to be clear, would you say the scenario in post #43, with the two existing 200 amp sets and panels, that that is a pretty straightforward load side connection where you could back feed about 160 amps?"

"Objection your honor he's leading the witness!"

Judge: "You may answer the question..."

Of course, but in some jurisdictions if there were not already two connections to the meter the POCO might not allow me to add one just for a PV interconnection. I don't know; it's a specific situation which I have never encountered, but as I said a while back, I don't do resi PV anymore; all I deal with is commercial systems which have, for the most part, way bigger than 400A services with CT cans which are off limits for PV interconnections in most of the utility jurisdictions I work in, which I believe brings me around full circle. These are the kinds of systems I have been talking about all along until the recent stuff about 400A services with two 200A panels.

When I did do resi PV nearly all the services I encountered were 200A or smaller, and the 400A services I saw were all as I described a couple of posts ago, i.e., they already had two 200A panels connected to them. But let me ask you this: are you saying that the POCOs you deal with will allow you to put a 320A revenue meter on a 200A service so that you can use the other lugs for PV?

 

[Hv&Lv]

So if a residential customer has an overhead service with a standalone meter can on the house, and wants to run a second set of service entrance conductors to an outbuilding, would your company (utility) allow the splice to be in the meter can (on the load side of meter)? Either with IPCs or with a factory lug kit or with a product like kwired showed in post #34?

Now if the splice isn't for an outbuilding service, but is instead for a second service disconnect on the house that will have PV behind it, does the answer change?

I would suggest that if the answer is different, that's illogical (unless there's some technical reason I'm missing?) Obviously your company can have illogical rules, but knowledgeable customers will still dislike it.

Cheers, Wayne

Probably will allow.
Heck, we have a couple installed with those connectors now. Makes for a clean installation.


Point is, it’s up to us to decide, not the electrician

 

[wwhitney]

Point is, it’s up to us to decide, not the electrician

That's fine as long as the utility publishes clear rules and enforces them consistently and rationally. Which certainly doesn't seem to have been the case for one poster in this thread. : - )

Cheers, Wayne

 

[electrofelon]

Of course, but in some jurisdictions if there were not already two connections to the meter the POCO might not allow me to add one just for a PV interconnection. I don't know; it's a specific situation which I have never encountered, but as I said a while back, I don't do resi PV anymore; all I deal with is commercial systems which have, for the most part, way bigger than 400A services with CT cans which are off limits for PV interconnections in most of the utility jurisdictions I work in, which I believe brings me around full circle. These are the kinds of systems I have been talking about all along until the recent stuff about 400A services with two 200A panels.

FWIW resi vs commercial shouldn't matter for my method (except use of 230.40 ex #3 of course). I was just using the 400 with 2 200 panels as a simple example to illustrate the ridiculousness of a utility that would allow this as a load side connection if it existed, but would not allow it to be installed

But let me ask you this: are you saying that the POCOs you deal with will allow you to put a 320A revenue meter on a 200A service so that you can use the other lugs for PV?

Yeah sure, what's the problem? Note I'm not using the other lugs for PV, I'm using them to supply another set of service conductors to a remote structure or another "normal" service disconnect

 

[ggunn]

FWIW resi vs commercial shouldn't matter for my method (except use of 230.40 ex #3 of course). I was just using the 400 with 2 200 panels as a simple example to illustrate the ridiculousness of a utility that would allow this as a load side connection if it existed, but would not allow it to be installed

It's rare (maybe never) that I have to design PV for a commercial service as small as 400A, so that particular point is moot.

Yeah sure, what's the problem? Note I'm not using the other lugs for PV, I'm using them to supply another set of service conductors to a remote structure or another "normal" service disconnect

I'll be in a meeting this afternoon with our resi designers this afternoon; I will ask them if they think any of the utilities we deal with would allow us to do that to install a supply side PV interconnection. Setting a 320A meter on 200A service conductors might be a problem for them, but I really don't know.

 

[electrofelon]

It's rare (maybe never) that I have to design PV for a commercial service as small as 400A, so that particular point is moot.

No it's not moot, the same principle applies to any size service. It's just like any service with two through six service disconnects would be built. You would run another set of service conductors off the CT cabinet or transformer or tap box however its setup. Obviously if the service already had six service disconnects then you would be out of luck.

I'll be in a meeting this afternoon with our resi designers this afternoon; I will ask them if they think any of the utilities we deal with would allow us to do that to install a supply side PV interconnection. Setting a 320A meter on 200A service conductors might be a problem for them, but I really don't know.

Again, it's not a supply side interconnection, It's just a service with two through six service disconnects that happens to have some load side connected PV in one of the panels.

 

[ggunn]

Then we are back to square one. There are utilities that I deal with who absolutely will not allow me to interconnect a PV system in their CT enclosure no matter how I try to justify it. I cannot argue for their position; I can only tell you what it is.

 

[electrofelon]

Then we are back to square one. There are utilities that I deal with who absolutely will not allow me to interconnect a PV system in their CT enclosure no matter how I try to justify it. I cannot argue for their position; I can only tell you what it is.

It would be interesting to ask one of these POCOs (or do it as a two step process and see what happens) if you could submit A non PV application to"upgrade the service" by adding the additional service conductors and service panel, and once that is completed, submit another separate application for a load side PV connection. Perhaps that would make them realize the absurdity of their position.

 

[Hv&Lv]

Setting a 320A meter on 200A service conductors might be a problem for them, but I really don't know.

I don’t really know why it would be a problem.
we set 200 amp meters on 100 amp services or saw services all the time.

 

[electrofelon]

I don’t really know why it would be a problem.
we set 200 amp meters on 100 amp services or saw services all the time.

I can't imagine what the issue would be either, but if there was someone on staff who doesn't really know what they are doing, anything is possible. A few years ago I installed a six-gang meter pack. The POCO field rep questioned why I had installed less conductor than the main bus rating of the meter pack. He admitted he could not find anything in his specs that prohibited it and I told him there was nothing in my rules that prohibited it and he let it go fortunately.

But back to the 320 socket, installation of the 320 on a distributed generation service has caused a slight bit of confusion a couple times. I think on two of our installs the POCO meter setter came out to install the net meter. He wasn't expecting to see a 320 socket and needed to go back and get a class 320 net meter (of course that was on the plans, but this utility isn't the most organized in the world). I think one time they actually had to order it and took a couple weeks. Of course we weren't installing the 320 for capacity so the 200 amp net meter would have been fine but I guess he didn't know that and just assumed he had to match the meter with the socket.

 

[Hv&Lv]

I can't imagine what the issue would be either, but if there was someone on staff who doesn't really know what they are doing, anything is possible. A few years ago I installed a six-gang meter pack. The POCO field rep questioned why I had installed less conductor than the main bus rating of the meter pack. He admitted he could not find anything in his specs that prohibited it and I told him there was nothing in my rules that prohibited it and he let it go fortunately.

But back to the 320 socket, installation of the 320 on a distributed generation service has caused a slight bit of confusion a couple times. I think on two of our installs the POCO meter setter came out to install the net meter. He wasn't expecting to see a 320 socket and needed to go back and get a class 320 net meter (of course that was on the plans, but this utility isn't the most organized in the world). I think one time they actually had to order it and took a couple weeks. Of course we weren't installing the 320 for capacity so the 200 amp net meter would have been fine but I guess he didn't know that and just assumed he had to match the meter with the socket.

I have no idea why people believe that either.