Q: Two weeks ago, you wrote about power generators for home backup. I have a couple of questions. Are manual transfer switches available in a range of maximum power to be transferred? Also, do they make automatic transfer switches that operate when no one is home during a power failure, and if so, what is the price range?

A: Many brands and types of transfer switches and generators are available, covering a wide variety of power and price ranges.

The system I described is not automatic because it's portable. When the power goes out, I have to wheel out my generator and connect it to the outside inlet box with a single 240-volt/30-amp connection. When the power returns, I turn off the generator and put it back in the garage.

The system you want is a backup (also called standby) generator, which usually ships with a prewired indoor automatic transfer switch. The backup generator is connected to the natural gas line (or a large propane tank if your home does not have natural gas) and the automatic transfer switch is wired to the electrical panel. The switch monitors the system, and if power from the grid is interrupted, the switch starts the generator. When utility power is flowing again, the switch will disconnect and turn off the generator.

The bigger the house and the more circuits you want to connect, the bigger the generator and more elaborate the transfer switch must be. Connecting appliances with high current and wattage requirements such as central air conditioners and electric ranges requires a bigger generator than if you just want to run a few lights and the refrigerator. Because the generator is intended for emergency purposes, most homeowners shy away from massive generators, instead choosing one with enough power to cover a few rooms and the appliances needed to stay comfortable (say, a microwave oven instead of an entire range).

A home backup generator with transfer switch starts at around $2,000, with another $2,000 typical for the installation. And those are the bargain-basement prices; the cost can run into tens of thousands of dollars for a very large home with all the circuits included. You definitely will want to get proposals from several dealers before deciding.

Wisconsin-based Generac Power Systems (generac.com) is the industry leader and has led the drive to bring down backup generator prices. The Generac PowerPact 7,500-watt unit includes a 50-amp automatic transfer switch for $2,049. All of their backup generators are CARB-compliant, and their website is very comprehensive, with downloadable brochures and a tool to help you determine how much generator you need.

Send questions to Don Lindich at donlindich@gmail.com. Get recommendations and read past columns at soundadvicenews.com.