Understanding 120/240V Wiring Color Code | DoItYourself They may, however, be capable of working with either type of wiring. If you are replacing an older cooking appliance or dryer, the instructions may tell you that you can, by replacing the cord on the appliance, connect it to an existing three-wire 240V circuit. There are still 240V appliances that only need two hot wires and a ground. 240 Volt Wiring for an Electric Dryer - Ask the Electrician Guide to 120/240 Volt Wiring for a Dryer Circuit . Electrical Question: We have a GE Electric dryer (Model- DBLR333EEEWW) says inside door 120/240Volt 60hz and then under that 120/208V 60hz has the NEMA 10-30R 30AMP power cord already attached. I also purchased the three prong power outlet to install that fits this cord.