Interconnecting into a Square D Meter Socket

[RickwithSisuSolar]

Hi everyone,

I have connected solar to a whole bunch of Milbank meter sockets with the MILBANK K4977 lugs. Is there something similar I can use for a square d meter socket? Picture of the one in question is below.

Thanks,
Rick

 

[texie]

I'm not aware of others making these. Things like this have always been a mystery to me. Something that should be readily available and such good idea one would like things like this to be more common place.

 

[Phil Timmons]

I generally hear that the Meter Base (with cover and meter in place) are no longer a "accessible" or serviceable piece of equipment. So we do not put grounding bushings, etc., in there. Dunno if this would be considered a junction type device or not. I do see some 320 meter bases with double barrel lugs built-in. When in doubt, you can always check with the AHJ -- that is what they get the Big Money and Glory for. ;P

 

[electrofelon]

I generally hear that the Meter Base (with cover and meter in place) are no longer a "accessible" or serviceable piece of equipment. So we do not put grounding bushings, etc., in there. Dunno if this would be considered a junction type device or not. I do see some 320 meter bases with double barrel lugs built-in. When in doubt, you can always check with the AHJ -- that is what they get the Big Money and Glory for. ;P

I see absolutely no issue with those lugs. There are some AHJ's and POCOs that consider a supply side interconnection a "tap" (IMO it's completely stupid) and thus place further restrictions beyond what "normal" conductors would have. Perhaps the solution is to qualify the new conductors under 230.40 exception #2 and supply the PV load side using the "sum of all OCPD's minus the supply OCPD" rule which would have the same capacity as a supply side connection.

 

[Tulsa Electrician]

Never seen them before, Interesting

 

[BandGap1.1eV]

Generally the utility will forbid you from even looking cross-eyed at their service equipment, never mind making a supply side connection in their equipment.

There was/is a meter socket manufacturer that included a seperate set of lugs on the load side specifically for this purpose, but their list of approved utilities is short. I think one or two Vermont utilities allow this to be installed.

 

[electrofelon]

Generally the utility will forbid you from even looking cross-eyed at their service equipment, never mind making a supply side connection in their equipment.

There was/is a meter socket manufacturer that included a seperate set of lugs on the load side specifically for this purpose, but their list of approved utilities is short. I think one or two Vermont utilities allow this to be installed.

What is the difference between this and using a class 320 socket with dual lugs? What is the difference between a supply side connection and two sets of service entrance conductors per 230.40 exception number two?

 

[ggunn]

What is the difference between this and using a class 320 socket with dual lugs? What is the difference between a supply side connection and two sets of service entrance conductors per 230.40 exception number two?

The difference is, as I have said before, that many utilities as a matter of policy will not allow us to make PV connections in their equipment. We can call it anything we want and throw all the code at it we want but they still will not allow it.

 

[electrofelon]

The difference is, as I have said before, that many utilities as a matter of policy will not allow us to make PV connections in their equipment. We can call it anything we want and throw all the code at it we want but they still will not allow it.

I would say it DOES matter what you call it. It's interesting the difference between PV people and electricians. And I genuinely mean no disrespect and I'm not putting anybody down.... But I have noticed people who enter the industry on a PV track tend to approach things differently than those who entered the industry as electricians initially. I have never actually made a "supply side connection" I have always used the 230.40 exceptions. I think it has saved a lot of hassle as I have skipped silly utility requirements about "taps or PV connections in the meter socket", avoided the dispute about bonding supply side connections, and just generally avoided lots of confusion on the silly supply side connection thing. You should try the 230.40 exception number two route I think it would save you a lot of hassle.

 

[jaggedben]

Generally the utility will forbid you from even looking cross-eyed at their service equipment, never mind making a supply side connection in their equipment.

There was/is a meter socket manufacturer that included a seperate set of lugs on the load side specifically for this purpose, but their list of approved utilities is short. I think one or two Vermont utilities allow this to be installed.

You realize that the meter socket doesn't belong to the utility, right? Only the meter itself does.

 

[ggunn]

I would say it DOES matter what you call it. It's interesting the difference between PV people and electricians. And I genuinely mean no disrespect and I'm not putting anybody down.... But I have noticed people who enter the industry on a PV track tend to approach things differently than those who entered the industry as electricians initially. I have never actually made a "supply side connection" I have always used the 230.40 exceptions. I think it has saved a lot of hassle as I have skipped silly utility requirements about "taps or PV connections in the meter socket", avoided the dispute about bonding supply side connections, and just generally avoided lots of confusion on the silly supply side connection thing. You should try the 230.40 exception number two route I think it would save you a lot of hassle.

No, it doesn't and it has nothing to do with my attitude. If a utility says that they do not allow PV connections in the meter can or the CT can, they mean it no matter what you call it. Utilities can have all sorts of rules applying to PV interconnections; for example, one or two that we deal with allow no PV interconnections on the line side of the customer's OCPD, no matter what. Another requires that all PV interconnections have to be supply side connected. Still another requires that PV interconnections must be made outside the customer's meter on its own meter - literally a separate service. With some utilities you can plead your case and get them to budge, but with others it is no way, Jose. The power is on their side, pun intended.

We deal with Austin Energy and CPS in San Antonio a lot. After you have dealt with these guys and got them to change one of their ironclad policies that doesn't conform to the NEC, get back to me and tell me how you did it.

 

[pv_n00b]

You realize that the meter socket doesn't belong to the utility, right? Only the meter itself does.

Utilities generally seal any access to the line side of the meter to prevent anyone from tapping in and getting free power. That usually means sealing the meter enclosure that holds the meter. Now there are over 3,000 utilities in the US so there are undoubtedly some that don't seal everything up, but all of them I have seen across many states and utilities do. Unless the utility allows access, which most don't, someone would not be able to tap on the load side in the meter enclosure.

 

[pv_n00b]

I would say it DOES matter what you call it. It's interesting the difference between PV people and electricians. And I genuinely mean no disrespect and I'm not putting anybody down.... But I have noticed people who enter the industry on a PV track tend to approach things differently than those who entered the industry as electricians initially. I have never actually made a "supply side connection" I have always used the 230.40 exceptions. I think it has saved a lot of hassle as I have skipped silly utility requirements about "taps or PV connections in the meter socket", avoided the dispute about bonding supply side connections, and just generally avoided lots of confusion on the silly supply side connection thing. You should try the 230.40 exception number two route I think it would save you a lot of hassle.

You have to ask yourself if you think you have found an easy way to do PV interconnections that no one else in the PV industry seems to know about, have you really found a way to do it that is right?
NEC 230.40 Exception 5 is what allows supply-side interconnections of parallel generators. None of the other exceptions apply to 230.82(6).

 

[wwhitney]

NEC 230.40 Exception 5 is what allows supply-side interconnections of parallel generators. None of the other exceptions apply to 230.82(6).

Sure, but once you have an additional service disconnects per 230.40 Exception 2, you don't need to use 230.82(6). You simply have one service that has a load-side connected PV on it and nothing else. Easy-peasy NEC wise.

Now, perhaps you need POCO approval to install the additional service disconnect under 230.40 Exception 2, and the POCO may have additional restrictions on a service disconnect that only has load-side connected PV on it.

Cheers, Wayne

 

[ggunn]

Sure, but once you have an additional service disconnects per 230.40 Exception 2, you don't need to use 230.82(6). You simply have one service that has a load-side connected PV on it and nothing else. Easy-peasy NEC wise.

Now, perhaps you need POCO approval to install the additional service disconnect under 230.40 Exception 2, and the POCO may have additional restrictions on a service disconnect that only has load-side connected PV on it.

Cheers, Wayne

It really all comes down to what the utility will allow, and some are more flexible than others. In my experience the utility plan reviewers do not care so much about what we are calling things but where the conductors connect and what is on them.

 

[wwhitney]

Austin Energy

Looking briefly at their DG Interconnection guide, other than the need for a separate PV meter downstream of the billing meter, and a seemingly stupid requirement for a full size neutral up to the "first DG equipment after the AC disconnect," what limitations do they impose? They have allowances for both "line side" and "load side" connections as usual.

Cheers, Wayne

 

[ggunn]

Looking briefly at their DG Interconnection guide, other than the need for a separate PV meter downstream of the billing meter, and a seemingly stupid requirement for a full size neutral up to the "first DG equipment after the AC disconnect," what limitations do they impose? They have allowances for both "line side" and "load side" connections as usual.

Cheers, Wayne

If you want to land PV conductors in the utility revenue meter can, you can't. I don't believe you will find that in their interconnection guide but if you do it they will fail you; they seal the meter can and if you break their seal they get very upset. CPS in San Antonio is even more restrictive. AE will allow connections via IPC's in the MDP but CPS will not; for CPS you must install a tap box between their meter and the MDP.

But my point in all this is only that utilities have policies regarding what they will and will not allow, and challenging those policies many times does not end well.

 

[electrofelon]

No, it doesn't and it has nothing to do with my attitude. If a utility says that they do not allow PV connections in the meter can or the CT can, they mean it no matter what you call it. Utilities can have all sorts of rules applying to PV interconnections; for example, one or two that we deal with allow no PV interconnections on the line side of the customer's OCPD, no matter what. Another requires that all PV interconnections have to be supply side connected. Still another requires that PV interconnections must be made outside the customer's meter on its own meter - literally a separate service. With some utilities you can plead your case and get them to budge, but with others it is no way, Jose. The power is on their side, pun intended.

We deal with Austin Energy and CPS in San Antonio a lot. After you have dealt with these guys and got them to change one of their ironclad policies that doesn't conform to the NEC, get back to me and tell me how you did it.

You have to ask yourself if you think you have found an easy way to do PV interconnections that no one else in the PV industry seems to know about, have you really found a way to do it that is right?
NEC 230.40 Exception 5 is what allows supply-side interconnections of parallel generators. None of the other exceptions apply to 230.82(6).

Ok I think you guys are just not seeing this correctly. You are stuck on the PV side of things and thinking like an electrician. Please take a look at this drawing, and let me walk you through some scenarios. Lets say this is a NEW BUILD starting from scratch. I think we would all agree there is no hocus pocus here. I dont see what the POCO could have an issue with, unless of course they require something like PV be on its own meter or service. For the absolute most simplicity, lets say the meter socket is a class 320 with dual lugs. Now say its just a 200A meter socket with those lug kits as discussed previously, or a splice in a box AFTER the meter socket. I still dont see how the POCO could have an issue with either of those scenarios. I could see them not liking those lug kits just because they arent that common and maybe they have never seen them, but what would they have in the specs that would prohibit them if they are listed and made and provided by the manufacturer?

Ok so now lets say you have an existing setup, with just a single service disconnect. Basically you are just starting with what is on my diagram minus service disconnect/panelboard #1. You provide my drawing to the POCO for "modification and expansion of electrical service to accommodate PV and additional loads". What would be the issue? They would have a allowed the setup as a new build, why would this expansion not be allowed? And one final point of discussion, on the previous sentence: Would adding a few "general load" breakers or convenience outlets onto The PV panelboard change anything and make it look more like "just a general use panelboard that happens to have some load side PV on it"?

 

[electrofelon]

If you want to land PV conductors in the utility revenue meter can, you can't.

I think this is where you stuck. Using 230.40 exceptions, they are just "normal" conductors now. PV is all load side.

 

[electrofelon]

Utilities generally seal any access to the line side of the meter to prevent anyone from tapping in and getting free power. That usually means sealing the meter enclosure that holds the meter. Now there are over 3,000 utilities in the US so there are undoubtedly some that don't seal everything up, but all of them I have seen across many states and utilities do. Unless the utility allows access, which most don't, someone would not be able to tap on the load side in the meter enclosure.

I dont see what the meter being sealed has to do with anything. As an electrician I do upgrades and repairs all the time that require POCO involvement, cutting the seal, getting a reseal, etc. PV pretty much always requires POCO involvement anyway so what is the issue?