Quick Answer
Permits and load calculation are completed before installation day. On-site, the crew places and levels the pad, sets the generator, runs electrical conduit and fuel lines, installs the transfer switch, and connects everything to the panel. After a functional test, a code inspector from your local permitting authority verifies the work before the project receives final sign-off.
Key Takeaways
- 1Permits and site assessment happen before any physical work begins — the crew arrives with a specific plan.
- 2On installation day: pad → generator set → electrical conduit → fuel line → transfer switch → panel connection → functional test.
- 3A brief power outage (often a few hours) is required while the transfer switch connects to the main panel.
- 4The final code inspection from the local authority is a separate step after the crew leaves — not optional.
- 5A homeowner walkthrough at the end covers self-test, remote monitoring setup, and warranty registration.
- 6Confirm site restoration (backfilled trenches, sod or mulch replaced) is included before signing the contract.
Before the crew arrives
By the time installation day arrives, the site assessment, load calculation, and permitting should already be done. The crew shows up with a specific plan: where the pad goes, how the fuel line runs, and where the transfer switch and panel connections happen.
On-site work
The pad is placed and leveled first, since the generator sits on it. Electrical work — running conduit, wiring the transfer switch, connecting to the panel — happens alongside fuel line installation (natural gas or propane, sized to the unit).
Once the generator is set on the pad and connected, the crew tests startup and transfer under a simulated outage before calling the work complete.
After the crew leaves
A code inspection from your local permitting authority typically follows, confirming the installation meets requirements before final sign-off. Most installers also do a homeowner walkthrough covering the weekly self-test, basic maintenance expectations, remote monitoring setup, and warranty registration.
Site cleanup and landscaping
Trenching for fuel and electrical lines disturbs some amount of yard, even on a straightforward job — a reasonable installer restores the disturbed area (backfilling trenches, replacing sod or mulch) as part of the standard scope rather than leaving it as an afterthought. It's worth asking what site restoration is included before work begins, especially if landscaping or hardscaping sits along the planned trench path.
Frequently asked questions
Sources
- NFPA 70 — National Electrical Code — Governs the electrical wiring and transfer switch requirements referenced throughout residential generator installation.
- NFPA 37 — Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines — Covers clearance, ventilation, and safety requirements for stationary standby generators.
What should you do next?
Know the right questions to ask before and after installation day so there are no surprises.
Questions to Ask an Installer →