I read a post on Craigslist looking for a property preservation mechanic. An electric generator was a “MUST HAVE” piece of equipment. I performed years of property preservation tasks and never took a generator to the field. This firm is probably requiring the “back feeding” or “charging of a house” which is very dangerous. Don’t kill yourself or someone else or damage property for some idiot on Craigslist whose has no concern for your safety or the safety of others.
Stay out of the main circuit breaker box unless you know what you are doing. I performed some research and learned that to legally connect to your homes electric, you will have to have a secure box that guarantees no power can go out into the line while the generator is on (the electric company says this is for the protection and safety of the line men working on the lines) and of course to stop the electric from going back into your generator when the power comes back on.
The wrong way and most used method is called “back feeding” or “charging a house”. This is where you would make a double male 240-v cord. Plug one end into your dryer outlet first and the other end into the generator. The problem with this is that when you don’t throw the main shutoff in your power panel (and you will forget. How many times have you lost your keys?) you will send power out to the lines and through a transformer. The best thing that could happen when this happens is the power comes on and fries your generator. The worst thing is that you kill a lineman. This method is used as a quick way to send power to your circuits and is HIGHLY dangerous. Most power companies will not authorize such connections.
Double ended male plug extension cord adapters are unsafe and dangerous. These devices are in violation of the U.S. Code Law 29 USC 654 and are prohibited by numerous OSHA standards. Qualified electrical workers as well as safety professionals have historically referred to this type of cord as a “suicide cord”, “death cord” and also a “widow maker”, which should also provide some insight as to the seriousness of the safety concerns.