There are two clocks. The first is scheduling: permits, material lead time, and the utility’s appointment to cut and restore service often take longer than the electrical work. The second is the outage on install day, when the meter is pulled, the service equipment is changed, and the utility reconnects and the inspector signs off. That outage is commonly measured in hours, not days, for a straightforward panel swap in the same location, but a relocated panel, an underground service, a failed inspection, or a delayed utility truck can stretch it. No national source we trust gives a single official hour count, so this page will not invent one.
What to ask for in writing before you agree:
- Who schedules the utility disconnect and reconnect, and the promised appointment window.
- How long the contractor expects the house to be without power, and what would make it longer.
- Whether you will have a temporary setup for food and medical devices, or whether you should plan to be elsewhere.
- Whether inspection happens the same day or whether you wait for a reconnect.
A same-location 100-to-200-amp heavy-up is a different day than a panel relocation or a trench. See the “what is included” page so the quote you are timing is the same job as the one being priced.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.