Never connect a standby generator into your home’s electrical system. There are only two safe ways to connect a standby generator to your equipment. 

Stationary Generator — An approved generator transfer switch, which keeps your house circuits separate from the electric co-op, should be installed by a professional. 

Portable Generator — Plug appliances directly into the outlet provided on the generator. 

Set up and run your generator in a well-ventilated area outside the home. Make sure it’s out and away from your garage, doors, windows and vents. The carbon monoxide generated is deadly.

Use a heavy-duty extension cord to connect electric appliances to the outlet on the generator. 

Start the generator first before connecting appliances. 

Source: Safeelectricity.org