A manual transfer switch is installed beside the main electrical panel and connected to the circuits you'll want running during a blackout.
When the power goes out, you simply crank up the generator and run a single power cord from it to a transfer switch.
Once the generator is running, you can choose which circuits to energize by simply flipping the switches.
The best way to size a manual transfer switch is to size your power cord first. If you need a 30-amp cord, you need a 30-amp transfer switch.
Think about it. The more powerful your generator; the more circuits you can power. Most 5,000 watt generators can restore power to six circuits. You should get a 10-circuit switch if you have a larger generator.
Most transfer switches come pre-wired with the circuit breakers already selected. If you have a unique installation, you should purchase a transfer switch with interchangeable breakers, so you can modify it exactly to your needs.
Most manual transfer switches also include built-in wattage meters, which keep track of what's being powered. Without them, you can overload the system, damaging your generator and appliances.
You have two options when installing a manual transfer switch. The easiest and least expensive way is to install it on the wall like a painting. This option works well in garages and unfinished basements.
If style matters, you can buy a mounting kit to recess the manual transfer switch into the wall. You simply inset it into the drywall between two studs.