Point Of Connection Question

[Plamen]

Hello,

I am new to the forum and the electrical industry and I am just getting into that not so easy field.

It is maybe an easy question for most of you guys but it bothers me and I am not sure about the answer.

The building that I am proposing a solar system for has one 800 amp main disconnect which supplies 7 meters with adjacent disconnects. 6 of the meters supply 150 amp disconnects and the 7th meter (the one getting solar) supplies 2 200 amp disconnects. Here is my question. Would my tap between the 7th meter and 2 disconnects be considered a load side connection which would fall under the 120% rule or a supply side connection? I believe that this is a load side connection and would require upsizing the feeder between the 800 amp disconnect and the meters to connect a system larger than what the 120% rule would permit. Please let me know if I am close in my thinking or if I am way off.

Thank you in advance !

 

[GoldDigger]

Hello,

I am new to the forum and the electrical industry and I am just getting into that not so easy field.

It is maybe an easy question for most of you guys but it bothers me and I am not sure about the answer.

The building that I am proposing a solar system for has one 800 amp main disconnect which supplies 7 meters with adjacent disconnects. 6 of the meters supply 150 amp disconnects and the 7th meter (the one getting solar) supplies 2 200 amp disconnects. Here is my question. Would my tap between the 7th meter and 2 disconnects be considered a load side connection which would fall under the 120% rule or a supply side connection? I believe that this is a load side connection and would require upsizing the feeder between the 800 amp disconnect and the meters to connect a system larger than what the 120% rule would permit. Please let me know if I am close in my thinking or if I am way off.

Thank you in advance !

You defined the muddled situation when you specified that there was an 800A main disconnect (with fuses or breaker for OCPD, maybe?).
A. If that is under owner control it could be the service point/main disconnect in the opinion of the NEC.
B. If it is under the exclusive control of POCO (and for sure if it does not contain OCPD) then it is not the main disconnect/service point.

In the latter case (B), the conductors between the 7th meter and its disconnect with OCPD would be service conductors, and line (supply) side for the purposes of PV backfeed. The backfeed would be limited only by the size of that (sub)service (200 or 400A) and not the size of any downstream breakers. The 120% rule would not apply since there is no upstream OCPD that counts, just as if the POCO transformer secondary were on the other side off the meter.

Does the POCO consider this one service to one building with their own submetering for tenant billing? Again, if so the point in question would be load side.

In the first case (A), the point you are looking at would be load side and you would apply the 120% rule to the feeder between the 800A breaker and your PV connection point.

My snap impression, while waiting for more information, is that you have A.