240V outlet wiring - Standard Color code for L1, L2 Pins X, Y (2024)

Is there a standard color code for the X & Y pins on a 240V connector?

Where is the color code Specified?

Where are the X & Y pins specified?

I am interested in NEMA 14-50 10-30 6-20, L6-20, L6-30 6-50

I see it wired both ways on the internet.

It makes a difference on Electric Vehicle Chargers when you create a 120V adapter. L2 is specified as neutral

dave6288 said:

Is there a standard color code for the X & Y pins on a 240V connector?

Where is the color code Specified?

Where are the X & Y pins specified?

I am interested in NEMA 14-50 10-30 6-20, L6-20, L6-30 6-50

I see it wired both ways on the internet.

It makes a difference on Electric Vehicle Chargers when you create a 120V adapter. L2 is specified as neutral

Click to expand...

What do you mean by color code?
On the 14-50, If you're using 240V, the X & Y are the hot terminals and it doesn't matter which 120V line runs to either one. The W is used for neutral.

10-30 X or Y could be used for hot and the other for neutral, W would be ground

6-20 no X Y markings

L6-20 is 240/250V only, doesn't matter which line wire goes to X or Y

L6-30 same as above

6-50 no X Y designation

There is nothing other the standard colour code in the NEC that white and green are reserved for grounded and grounding conductors.

I think the reason you are seeing L2 for neutral is convention, we've always labeled things L1 and neutral, or L1 and L2. No one ever labels anything L2 and neutral.

ActionDave said:

There is nothing other the standard colour code in the NEC that white and green are reserved for grounded and grounding conductors.

I think the reason you are seeing L2 for neutral is convention, we've always labeled things L1 and neutral, or L1 and L2. No one ever labels anything L2 and neutral.

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Don't forget isolated power supplies- but chances are the OP is not dealing with that.

mbrooke said:

Don't forget isolated power supplies- but chances are the OP is not dealing with that.

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Ya think? He's asking about a car charger.

Little Bill said:

10-30 X or Y could be used for hot and the other for neutral, W would be ground

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Funny that this use W for the EGC and in other configuration the W is the neutral. Also for 120 volts shouldn't the neutral always be landed on the same letter when you have X and Y?

ActionDave said:

Ya think? He's asking about a car charger.

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:lol::ashamed1::ashamed1: Lesson learned, I will not speed read posts! :happyyes:

infinity said:

Funny that this use W for the EGC and in other configuration the W is the neutral. Also for 120 volts shouldn't the neutral always be landed on the same letter when you have X and Y?

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10-30 is 125/250 volt non grounding configuration - three wire dryer receptacle, when used as intended the W is a neutral conductor for an appliance that is allowed to have it's frame bonded to the neutral, the W terminal is not bonded to the device yoke though.

infinity said:

Funny that this use W for the EGC and in other configuration the W is the neutral. Also for 120 volts shouldn't the neutral always be landed on the same letter when you have X and Y?

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I didn't state it should because the OP asked if there was a standard or requirement. But I would think that one or the other would be used consistently. If I'm not mistaken, I've seen and used the Y as the neutral for those that are combo 125/250V.

Now you may ask "Y" not the "X" for neutral!

kwired said:

10-30 is 125/250 volt non grounding configuration - three wire dryer receptacle, when used as intended the W is a neutral conductor for an appliance that is allowed to have it's frame bonded to the neutral, the W terminal is not bonded to the device yoke though.

Click to expand...

Ah that make sense, there is no EGC with that configuration. I don't think that I have ever installed one of those.

infinity said:

Ah that make sense, there is no EGC with that configuration. I don't think that I have ever installed one of those.

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My best recollection is most of those only have the neutral terminal identified with W, the other two don't matter and usually are not even marked with anything.

Add: if using it for it's intended purpose.

Electric Vehicle Charger (EVSE) - Adapter wiring 120/240 Volt L2 is Neutral

Electric Vehicle Charger (EVSE) - Adapter wiring 120/240 Volt L2 is Neutral

How does this look?

The EV charger also called Electric Vehicle Service Equipment (EVSE) J1772 connector spec states that L2 is Neutral when operating on 120V. This creates a problem when using a 120V adapter if the 240V connector is not wired consistently. We typically use 6-20, L6-20, 6-50, 10-30 and 14-50 plugs and receptacles. Also need a consistent x & Y designation

below is the convention that I am using to manufacture adapters but I want to make sure that it is correct.