Stuck on this subpanel upgrade in north jersey, what's the right way?

SawdustSavant6

·1d·4 replies·5 participants

SawdustSavant6⚒️ JourneymanOP1d

Hey folks, I'm a couple years into electrical work and just got handed a job to upgrade a 100A subpanel to 200A for this old house in north jersey. The main's already 200A with a Square D QO setup, but the run to the sub is only 2/0 copper and the homeowner's bitching about the $4500 quote I threw out. I'm worried about NEC 250.24 for grounding and if I need to upsize the neutral too. Also, the inspector here is a stickler for everything. Any tips from you vets on avoiding callbacks? This is my first big one solo.

RollerRogue9⚒️ Journeyman2h

don't skimp on upsizing that neutral or you'll have the jersey inspector red-tagging the whole damn job like happened to a buddy last summer.

SparkPlugger⚒️ Journeyman1h

don't skimp on that ground wire, use at least 2 awg copper for the 200a sub or you'll get red-tagged faster than you can say callback. jersey inspectors love to nail you on nec 250.24 if the egc isn't bonded right at the main, and i've seen guys redo whole runs because they forgot to upsize the neutral to match the hots. upsizing it to 1/0 will save you headaches down the line, especially with that 2/0 feed. trust me, one pissed-off ahj and you're out another grand in labor.

V7213⚒️ Journeyman53m

for that 2/0 copper run, you're fine sticking with it for the 200A sub but upsize the neutral to 3/0 to match load calcs under 215.2, and on 250.24 just bond the sub neutral to ground with a screw like the qo kit specifies, north jersey inspectors eat that up without callbacks.

MopAndGloGuy⚒️ Journeyman1d

Man, north jersey inspectors are the worst, I had one fail me last month over a stupid label that wasnt even required. Just double-check your torque specs and label everything crystal clear, saved my ass on the last one. Dont skimp on the lugs either.