What’s the Difference Between an Automatic and a Manual Generator Transfer Switch?

Standby and portable generators provide electricity to run vital appliances and electronic devices during power outages. Though there are many crucial differences between the two types of generators, including fuel sources, pricing, and ease of use, they both require generator transfer switches.

Generator transfer switches allow users to transfer the home’s electricity source from the municipal grid to the generator if the power cuts out. Standby generators generally have automatic switches, while portable generators feature manual models. In both cases, the generators can only be used safely if they have transfer switches installed.

Automatic Transfer Switches

Standby generators must be installed by licensed electricians. Unlike portable models, they’re designed to be connected directly to a home’s electrical circuits. They generally come with built-in automatic transfer switches that transfer the power from the grid to the generator within seconds of the power turning off.

Automatic switches work by monitoring the flow of electricity coming from the municipal grid. When the flow is interrupted, it triggers the switch and turns the standby generator on. The generator then begins to power all of the home’s electrical circuits.

The automatic Generator transfer switch will continue to monitor grid-provided power for the duration of the outage. When it detects a return to normal voltage, it will transfer the home’s power back to the municipal electricity lines and cut off power from the generator.

Manual Transfer Switches

Portable generators usually feature manual transfer switches. These switches can be installed outside or inside depending on the model. They’re less convenient than automatic transfer switches but just as effective.

When the power goes out, homeowners with portable generators must go outside, connect the generator to the inlet box, and flip the manual transfer switch before turning it on. From there, it will begin to provide power to the applicable circuits.

Residents with portable generators will have to monitor the state of the municipal power grid themselves. When the grid goes back up, they can go outside, flip the transfer switch to put the home back on the grid, turn off the generator, and unplug it from the inlet box.

Installing Transfer Switches

Homeowners with standby generators don’t need to worry about installing transfer switches. They’re built into all popular models and must be installed by a qualified electrician. Families that choose to use portable generators instead will find themselves in a different boat.

Most homeowners who choose portable generators still have their manual transfer switches installed by professional electricians. The process involves locating the electrical panel, mounting the transfer switch securely nearby, and connecting the wires to the relevant circuit breakers in the panel box.

Unless one or more of the home’s residents have experience with electrical work, it’s best to leave the installation to a professional. An improperly sized or unprofessionally installed transfer switch can pose serious safety hazards.

The Bottom Line

Every home that has a generator also needs to have a transfer switch. Homeowners who purchase portable generators should plan to have the switch installed by a professional before they use them.