Geoscience Reference
In-Depth Information
A transfer switch is an electrical device to ensure that whenever electrical contact is made
between the generator and the home's electrical system, a circuit breaker simultaneously breaks
the electrical connection between the home and the power grid, and vice versa. This ensures
that your generator will not electrify the grid in your neighborhood, possibly electrocuting
someone working on local grid wiring, expecting that there would be no power running
through the local power lines. Additionally, since there is no way that your small generator
could power the entire neighborhood, your home must be disconnected from the grid whenever
your generator is hooked into your home's electrical system.
For manual transfer switches applicable to powering your home from a modest-sized
backup generator, there are two main categories of transfer switches. The option that gives you
the most flexibility is to have an electrician install a large-capacity transfer switch, commonly
known as a “transfer panel” (see
fig. 4-11
).
Figure 4-11. Power-center manual transfer panel.
Photo courtesy of Reliance Controls
Option 1, Manual Transfer Panel
This transfer panel must be the same size capacity as the main power panel for your home. For
example, my home has a 200-amp main breaker, so if I were to use this option, I would need to
have my electrician install a 200-amp transfer panel right alongside my home's 200-amp main
panel load center. The electrician would run the heavy-gauge wires directly from my electric
meter into the transfer panel, then back from the transfer panel to the bus bars (the bus bars are
