A standby generator is basically brain dead without an automatic transfer switch.
They are similar to the thermostat in your house. Instead of monitoring temperature, an automatic transfer switch monitors utility power.
When the power goes out, the automatic transfer switch tells the generator to start.
1. Select a Size
Automatic transfer switches come in a variety of amps, ranging from 100-amps to 200-amps to 400-amps.
In most cases, you simply match the transfer switch to the main breaker in your electrical panel. For example, if you have a 200-amp main breaker, you'll need a 200-amp automatic transfer switch.
2. Select a Style
Automatic Transfer Switches come in one of three styles:
These prehistoric (or pre-Y2K) automatic transfer switches are usually custom ordered by older electricians who love installing unnecessary sub-panels. Standard automatic transfer switches are rarely bundled with home standby generators any more. Stay away if possible.
Instead of installing an automatic transfer switch AND a sub-panel, most manufacturers combine the best of both worlds into a single switch.
Load centers are ideal for standby generators powering small homes with 100-amp inbound service. Your electrician simply connects the load center to 8-16 mission critical circuits.
Unless you own a really small home, youíll still experience a mini-blackout with a load center. When a high-demand appliance Ė like a central air conditioner Ė turns off, the extra electricity generated cannot be diverted to other circuits.
If 16 circuits just arenít enough, you can opt for an automatic transfer switch with service entrance disconnect, which energizes your entire electrical panel. They are best suited for larger generators powering homes with 200-amp service.
Your electrician installs it between your meter and electrical panel. While their initial cost is usually greater than a load center, you donít need to purchase a sub-panel. Plus, they are typically easier to install than a load center.