200A Leviton Main Panel — Zinsco Swap, Home Addition

This job combined two things that often come up together on home additions: a panel upgrade that was already overdue and a new service point to power the addition itself.

The existing main panel was a Zinsco — a brand that's been on the problem list for decades. Zinsco breakers are known for failing to trip under fault conditions, which means the protection they're supposed to provide doesn't always work. Most insurers won't cover a home with a Zinsco panel, and any licensed contractor doing permitted work on a house with one will flag it. It wasn't a question of whether to replace it — it was a question of when.

The new main is a Leviton 200A panel. Leviton's load centers are well-regarded in the trade — the bus design is clean, breaker slots are easy to work in, and the AFCI/GFCI combo breakers are some of the most reliable available. The panel was set in rough framing during the addition build, which is the right time to do it: easier access, no finished walls to cut into, and the inspector can see everything clearly.

A Leviton subpanel feeds the addition itself, taking a feeder from the new main. That keeps the addition's circuits separated and leaves room in the main panel for future loads. The meter socket was roughed in with the conduit and feeder conductors staged for the utility to make their connection before energizing.

Photos here show the full sequence: meter rough-in, subpanel set in framing, main panel interior with all breakers landed, and the finished exterior with the door open. That's the kind of documentation that makes inspections straightforward.