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I think I wired this the right way but I can't find an online reference that I trust enough to flip the breaker back on.

This is how I wired it.

Is this correct?

enter image description here

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1 Answer 1

up vote 14 down vote accepted

That is correct.

See NEMA 14-50R

NEMA 50A Table


G - Ground
W - Neutral
X - Hot
Y - Hot

If you look at the terminal screws on one of these receptacles, you may notice they are different colors.

enter image description here

The green tinted screw is ground.
The silver screw is neutral.
The two brass screws are hot.

This is a common pattern in most electrical devices, and can easily be remembered with a simple poem.
Black to brass, or you'll fry your ass.

As @HillBilly.Developer pointed out, since the red and black wires are both hot it doesn't matter which one is connected to X or Y. Each hot wire will have an electric potential of 120V to neutral/ground, and 240V potential to each other. This is because in US residential wiring, the house is fed from a transformer with a center tapped secondary. So the building is supplied using two hot legs (L1,L2) which are 180° "out of phase", and the center tap (N).

enter image description here

Because of this, any device in the house can be powered using either 120V, 240V or both. To supply 240V to a device, a hot wire from each leg of the system must be present at the outlet.

In our situation one leg of the system is the black wire (L1), and the other is the red wire (L2). So either way you hook them up, you'll always have 120V potential L1 to N and L2 to N and 240V potential L1 to L2.

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Perfect reference Tester. +++ –  shirlock homes Mar 22 '12 at 12:18
A question about your answer to the question...according to that diagram and the legend, Red & Black COULD be swapped, and still be correct? –  Calvin Allen Mar 22 '12 at 16:33
@HillBilly.Developer Yes, red and black can indeed be swapped without an issue. –  Tester101 Mar 22 '12 at 16:42
While I am not questioning your answer I think its crazy in your country you can have so many different outlets/plugs. I am thankful we have but only one! It makes things much easier! –  Ryan Walkowski Mar 23 '12 at 1:59
@walkowski It's for safety. It's meant to prevent people from plugging the wrong thing in the wrong place. –  Tester101 Mar 23 '12 at 10:38

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