PV Interconnection and NEC 230.40

[pvgreeze]

Hi everyone,

I'm very new to PV design, and I have run up against a couple of problems that I could use some advice on.

I'm working on a solar system design in a building with a brand new electrical service. The main electrical engineer sent me his plans, and it looks like he is using the NEC 230.40 Exception 2 in his main distribution panel (MDP). There are two planned circuits off MDP (800A and 400A), two spaces for spares, and a dedicated section for our PV interconnection (load side of an 800A breaker). My question is, without a single utility disconnection point, could this solar design be rejected from an interconnection perspective? Technically, we would still be under six disconnecting points, as spelled out in the NEC. I apologize if this is a very basic/easy question, but I just was not sure, and I do not really have many other engineering resources to turn to within the office I work at.

Thanks in advance!!
PVG

 

[jaggedben]

There is nothing wrong with the design. Generally utilities have not much say in how customer equipment is configured. That is not to say that your local jurisdiction or utility won't have some stupid rule that you run up against, but there is no general reason you should be concerned about this design.

 

[electrofelon]

Hi everyone,

I'm very new to PV design, and I have run up against a couple of problems that I could use some advice on.

I'm working on a solar system design in a building with a brand new electrical service. The main electrical engineer sent me his plans, and it looks like he is using the NEC 230.40 Exception 2 in his main distribution panel (MDP). There are two planned circuits off MDP (800A and 400A), two spaces for spares, and a dedicated section for our PV interconnection (load side of an 800A breaker). My question is, without a single utility disconnection point, could this solar design be rejected from an interconnection perspective? Technically, we would still be under six disconnecting points, as spelled out in the NEC. I apologize if this is a very basic/easy question, but I just was not sure, and I do not really have many other engineering resources to turn to within the office I work at.

Thanks in advance!!
PVG

So 230.40 is not the applicable section to your setup. See 230.90 ex #3. Also note your setup would not be allowed under the 2020 NEC.