Installing a backup generator for your home is a significant project that requires careful planning, proper sizing, and professional electrical work. The result — reliable power during outages — can make a meaningful difference for families with medical equipment, those in outage-prone areas, or anyone who works from home. This guide covers how backup generator installation works from start to finish.
Contents
⚡ Key Takeaways
- Before installation begins, you need to select the right type and size of generator:
- Generator sizing depends on which circuits you want to power during an outage.
- A complete standby generator installation involves several coordinated steps:
Choosing the Right Generator for Your Home
Before installation begins, you need to select the right type and size of generator:
- Portable generators: Lower upfront cost ($500 – $3,000); must be started manually; connected via a manual transfer switch; limited output (3,000 – 12,000 watts)
- Standby generators: Higher upfront cost ($3,000 – $15,000+); start automatically within seconds of an outage; connected via an automatic transfer switch; run on natural gas or propane
For true whole-home protection with automatic operation, a standby generator is the preferred choice. For occasional outage coverage of essential circuits, a portable generator with a manual transfer switch is a more affordable option.
Sizing Your Generator
Generator sizing depends on which circuits you want to power during an outage. A licensed electrician performs — a requirement under National Electrical Code (NEC) Article 702 governing standby power systems — a load calculation based on your appliances and determines the right kilowatt rating:
- 7–10 kW: Essential circuits only (lights, refrigerator, furnace, sump pump, some outlets)
- 14–20 kW: Most of the home, including central air conditioning
- 22+ kW: Whole-home coverage including large appliances and electric heating
The Backup Generator Installation Process
A complete standby generator installation involves several coordinated steps:
- Site selection: The generator is placed on a concrete pad at least 18 inches from the home, away from windows and doors
- Gas line connection: A licensed plumber or gas fitter connects the generator to the natural gas supply or installs a propane tank
- Transfer switch installation: A licensed electrician installs an automatic transfer switch adjacent to your main panel
- Panel wiring: The ATS is wired to the main panel, isolating your home from the utility grid when generator power is active
- Commissioning and testing: The system is started, tested under load, and the automatic switchover is verified
- Permit and inspection: Required in virtually every jurisdiction; the electrician handles this
How Long Installation Takes
The electrical and mechanical installation typically takes 1–2 days. Permit processing, utility scheduling, and gas line work can extend the overall project timeline to 1–3 weeks. Planning ahead of storm season is strongly recommended — demand for generator installation surges after major outage events.
Generator installation requires a licensed electrician for safe, code-compliant hookup. Our generator installation team handles everything from sizing to transfer switch connection.
Generator Maintenance After Installation
Standby generators require annual maintenance to remain reliable. This includes:
- Oil and filter change
- Air filter inspection and replacement
- Battery check and replacement if needed
- Spark plug inspection
- Load bank test to verify full output capacity
Most manufacturers require documented annual service to maintain the warranty. Many electricians and generator dealers offer annual service contracts.
Frequently Asked Questions
Can I install a generator myself?
No. Generator installation requires a licensed electrician for the transfer switch and panel wiring, and typically a licensed gas fitter for the fuel line connection. Permits and inspections are mandatory. Improper installation creates backfeed hazards that can be fatal to utility workers.
How often does a standby generator run without an outage?
Most standby generators are programmed to run a self-test cycle automatically once per week for 10–20 minutes. This exercises the engine, charges the battery, and confirms the system is ready for use.
What fuel type is best for a standby generator?
Natural gas is preferred for convenience — it connects to the existing supply line with no refueling required. Propane is a good alternative where natural gas isn’t available. Diesel generators are used in commercial applications but are less common for residential installations due to fuel storage requirements.
How far from the house does a generator need to be?
Most manufacturers require a minimum of 18 inches from the structure, and local codes often specify greater clearances from windows, doors, and gas meters. Your electrician will ensure placement meets all applicable requirements.