residential wiring diagram for 240-volt circuits
A simple residential wiring diagram for 240-volt appliances or fixtures is easy to understand because it is a dedicated circuit. Only one thing is on the circuit. This is usually because the one appliance takes a lot of electricity and it is part of a code or regulation to wire it that way.
The clothes dryer outlet above is one of these circuits. It usually has a 30-amp breaker at the breaker box. We use 10-3 Romex for the cable. We need all three wires plus the ground wire to connect to the dryer outlet plug.
The black and red wires will supply 2 hot lines of 120-volts each and will connect to the hot terminals on the plug, usually one on each side.
The white wire will connect to the neutral part of the plug and at the breaker box, it will connect to the neutral bus bar. The copper ground wire will connect to the ground part of the plug and then at the breaker box, will also connect to the neutral bus bar.
The water heater doesn't have an outlet plug. It is what we call "hard-wired". That means the 10-3 Romex cable will enter in through the top of the water heater and connect directly with the wires inside the water heater.
Most local codes will make you encase the Romex in metallic wire loom or shielding from where it comes out of the wall to where it enters the water heater.
Wiring a range/oven will usually take a 50-amp breaker at the breaker box. It will need special range/oven wire. You can get it at Home depot or at any electrical wholesale store. This is something like two 6-gauge hot wires, one-8-gauge neutral wire, and one ground wire.
The plug is wired much the same as a dryer outlet plug.
HVAC systems (heating, venting, air-conditioning) are usually wired a lot like a water heater where the wiring is hard-wired inside the unit. There are many different kinds that each have different requirements.
It's good to know what type of furnace and air-conditioner you will be using before you do the residential-wiring-diagram for these appliances and fixtures.
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