Another electrical question

[Nima]

Hi:

Does a 220 outlet has (or suppose to have) a white wire? My 220 outlet has only 3 wires: black, red and ground. No white wire is needed?!

[truckster]

A single-phase 220 circuit has two hot wires (red and black) and a ground.

[Nima]

Thank you.
So there is no neutral on a 220 outlet, the red connects where the white usually connects?

[truckster]

They're totally different. Think of it this way: the electrical service brought into your house is 220 volts single phase. In your breaker box, you have two strips of breakers; each one is for one "side" of the phase. In other words, the two phases are 180 degrees out of sync. When you wire a 110v circuit, it's connected to one of the phases on the hot side (black wire) and goes to ground through the neutral (white) wire, which completes the circuit. The bare copper wire is a ground, which is there for safety's sake.

When you connect both phases (really, both sides of one sine wave), you end up with 220v; one phase is represented by the black wire and the other by the red wire. Since the circuit is completed by the two hot wires, you don't need a neutral. Again, the ground is there as a safety measure. So a 220v outlet is different from a 110v outlet, and you should never (NEVER!) substitute one for the other.

To make things a little more confusing, some 220v outlets (such as for electric clothes dryers or stoves) DO have a neutral leg, and as a result will have a 4-prong cord instead of a 3-prong cord. That's because those appliances use both 220v (for the burners, for example) and 110v (for the clock). The older electrical code allowed for the use of the ground wire in that type of circuit to complete the 110v leg, but current code requires a separate neutral wire. It is permissible, however, if you have a newer appliance and an older outlet to use a 4-prong to 3-prong pigtail

I hope this helps.

[ERASER5]

If the white wire exits, then in the future, you can split the 220V into two 110v circuits without having to pull new wire.

For now, cap the white wire with a wirenut and fold it into the back of the box. A future owner will thank you.

[truckster]

Originally Posted by ERASER5

If the white wire exits, then in the future, you can split the 220V into two 110v circuits without having to pull new wire.

For now, cap the white wire with a wirenut and fold it into the back of the box. A future owner will thank you.

The OP was concerned with the lack of a white wire, so there wouldn't be anything to cap.

[ERASER5]

Yep. Missed that. Need more caffeine.

[Nima]

Originally Posted by truckster

They're totally different. Think of it this way: the electrical service brought into your house is 220 volts single phase. In your breaker box, you have two strips of breakers; each one is for one "side" of the phase. In other words, the two phases are 180 degrees out of sync. When you wire a 110v circuit, it's connected to one of the phases on the hot side (black wire) and goes to ground through the neutral (white) wire, which completes the circuit. The bare copper wire is a ground, which is there for safety's sake.

When you connect both phases (really, both sides of one sine wave), you end up with 220v; one phase is represented by the black wire and the other by the red wire. Since the circuit is completed by the two hot wires, you don't need a neutral. Again, the ground is there as a safety measure. So a 220v outlet is different from a 110v outlet, and you should never (NEVER!) substitute one for the other.


To make things a little more confusing, some 220v outlets (such as for electric clothes dryers or stoves) DO have a neutral leg, and as a result will have a 4-prong cord instead of a 3-prong cord. That's because those appliances use both 220v (for the burners, for example) and 110v (for the clock). The older electrical code allowed for the use of the ground wire in that type of circuit to complete the 110v leg, but current code requires a separate neutral wire. It is permissible, however, if you have a newer appliance and an older outlet to use a 4-prong to 3-prong pigtail

I hope this helps.

Thank you for simple but detailed explanation. It is very helpful.

Thank you all.

[motornut]

my dryer the 240 VAC is split to two 120s in the dryer,1 runs the drum ,2 the heat

stove is 240 split as well,
it just spits the power down to front burners/back,lower bake /upper broil.