Manual transfer switches offer one of the most economical ways to legally connect a portable generator to the hard-wired circuitry of a house. Photo by Photo Steve Maxwell ...

Without a transfer switch, you can only use a portable generator’s built-in outlets, which can power some appliances and electronics through an extension cord (for more, see below).

Consumer Reports says to keep in mind that the generator must be at least 5,000 watts to easily connect to a transfer switch and to handle the load of several appliances.