Load Side/Line Side Clarification

[broussardchris333]

First post here. Got a unique setup here and want to help clarify a disagreement I and a co-worker have on our interpretation of the rules.

We are looking to do a line-side tap connection on our solar connections. The current electrical setup is ( Utility Meter > 200A Fused Service Disconnect > ~200ft of Trenching > 200A Loadcenter with 200A main breaker)

My understanding is that the tap would need to happen prior to the 200A fused service disco and anything past would be load-side. I worry about potentially tripping the 200A main breaker downstream frequently. Could y'all help clarify and settle this for me? Code citations would be awesome so I can match the book to our site. Thanks!

Scribled picture attached.

https://imgur.com/a/BUJgGbl

 

[Master Nater]

i was about to tell you to look at "supply-side connections" in 705.11, but it looks like they've re-named it in the 2023 NEC to "source connections."

take a look at "source side connections" in 705.11 versus "load side connections" in 705.12.

the main issue being that when a load has a potential of being fed from two different directions, it potentially over-rules overcurrent protection devices. making a supply-side (or now source side connection) negates these issues. hence, why the code requirements are so much smaller and easier to abide by.

 

[jaggedben]

Your point B is the supply side tap. Your point A is a load side tap. Because there's a main breaker in the 200A panel you can really tap at either point here. I'd probably pick the load side tap because I don't need to pull the meter or involve the utility.

There's no worry about tripping the downstream 200A breaker because the loads still determine how much current is drawn on that panel. (Think about what's keeping it from tripping now.) However if that main breaker *weren't* there, you'd have a concern about overloading the panel, and the supply side tap would be the code compliant way unless you could install that breaker in the panel.

They keep renumbering the code sections every cycle, but 705.11 and 705.12 as mentioned previously is correct. The feeder tap rules (load side) have been in the first numbered or lettered subsection of 705.12 for the last few cycles.