I have an existing 240 outlet wired into the wall of my shop. It's there to run a phase converter that I use about 2 hours a week. I want to use this circuit to run a 240 window air conditioner when the phase converter is off.
The air conditioner arrived today and has only 3 conductors on the power cord. I looked up the configuration and determined that it's a 240v 15 amp set up.
I want to make a short extension cord, about 6 ft, to connect the 3 conductor plug from the AC to the 4 conductor 240v wall receptacle. The wall side would be an 4 conductor plug that fits the receptacle. The AC side would be a 3 conductor receptacle that fits the end of the AC power cord. So my extension cord would only be 3 conductor (no ground) going into the 4 conductor wall receptacle.
I've spent enough time around electricians to know how to connect wires and such safely. Just not sure if omitting the ground will work. The manufacturer of the AC apparently thinks so or they would not have made it with only 3 conductors.
Best Answer
To do this properly, You'll likely have to run a new circuit. Since you haven't posted the make, model, or nameplates of the equipment, it's impossible to say for sure if these two devices can be on the same circuit. If they can, the solution is to extend the circuit using approved methods and materials. If they can't, the solution is to run a new circuit.
As for making an extension cord, that's not the best option. Extension cords are for temporary use only, and should not be used in place of permanent wiring.
WARNING:
Using an extension/adapter cord like this is dangerous, and can lead to loss of property and/or life. This is a theoretical device, that should never exist. DO NOT make, use, or even think about a device like this.
WARNING:
Using an extension/adapter cord like this is dangerous, and can lead to loss of property and/or life. This is a theoretical device, that should never exist. DO NOT make, use, or even think about a device like this.
The safest option would be to install a new panel, and have it being fed by the conductors that are currently feeding the 14-50 receptacle. Then you can branch to each of the devices from the panel, using proper methods and materials.