I am not an electrician, but I am concerned about the safety of a job that an electrician has proposed for my kitchen. I am installing a 30 inch wall oven where a microwave used to be. The oven power rating is for 240V, 20 amps. Because of the layout of my house, it is very difficult to run a new electrical line from the sub panel to the kitchen. Therefore, the electrician is proposing to use the existing wires from a 120V/20amp wall outlet (that was dedicated for my microwave) to create a 240V junction box by rewiring the neutral line as a second hot line, and using the ground as the neutral line. He told me that the existing wiring is already rated for 20 amps, so this should be no problem. He said he just needs to install a double pole breaker switch in the sub panel where each is rated for 20 amps. I think my main concern is with the size of the wires being used - these are thinner wires from a regular wall outlet. I was under the impression that a job such as this required the much thicker wires that I've seen in other 240V junction boxes.
Is this safe? Thanks.
