A generator is wired into a home or building using a transfer switch, which safely connects the generator to specific circuits while isolating it from the utility power grid. This prevents dangerous backfeeding.
Here's a breakdown of the wiring process:
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Generator to Genset Cord: The generator's power output is connected to a specialized, heavy-duty electrical cord called a genset cord. This cord is designed to handle the generator's voltage and amperage.
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Genset Cord to Receptacle: The genset cord plugs into a receptacle (outlet) that is specifically designed for generator connections. This receptacle is often located outside the house for easy access.
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Receptacle to Interior Cable: Inside the house, the receptacle is wired to a dedicated cable. This cable runs directly to the transfer switch.
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Transfer Switch: The transfer switch is the central component. It allows you to switch between utility power and generator power. It has circuit breakers that connect to the essential circuits you want to power with the generator (e.g., refrigerator, lights, furnace).
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Circuit Breakers to Circuits: The transfer switch's circuit breakers are then connected to the individual circuits you've selected to be powered by the generator.
Why is a Transfer Switch Necessary?
- Safety: Prevents backfeeding. Backfeeding occurs when generator power flows back into the utility grid. This can energize power lines and pose a serious risk to utility workers and neighbors.
- Code Compliance: Most electrical codes require the use of a transfer switch when connecting a generator to a building's electrical system.
- Prevent Damage: Protects the generator and the building's electrical system from potential damage caused by voltage fluctuations or power surges when switching between power sources.
Different Types of Transfer Switches:
- Manual Transfer Switch: Requires you to manually switch between utility power and generator power.
- Automatic Transfer Switch (ATS): Automatically switches to generator power when a power outage is detected. This provides a seamless transition, especially useful for critical applications.
Important Considerations:
- Professional Installation: Wiring a generator and installing a transfer switch should always be done by a qualified electrician to ensure safety and compliance with local electrical codes.
- Generator Sizing: The generator must be properly sized to handle the electrical load of the circuits you intend to power. Overloading the generator can damage it and the connected appliances.
- Grounding: Proper grounding is crucial for safety. The generator and transfer switch must be properly grounded according to electrical codes.
In summary, wiring a generator involves connecting it through a genset cord to a receptacle, then through interior cabling to a transfer switch. The transfer switch then distributes the generator's power to selected circuits in the building, ensuring safe operation and preventing backfeeding.
