Wiring 3-wire cord for L6-20 or L14-20?

[RMessenger]

My controller's power cord has three wires (white, black, and green). I was originally planning to use an existing 3-wire outlet for brewing, but then I figured out that it has the wrong three wires (white, black, and copper ground). So I am running a new line of 12/3 (white, black, green, and copper ground) to a GFCI breaker. Should I use a L6-20 (3-prong) outlet and plug (leaving the copper ground unattached in the box so that I can upgrade to a 4-prong plug if I ever want to) or can I install a L14-20 outlet and just attach the white, black, and green wire from the cord of the controller to the two hot and neutral posts on the plug?

 

[raouliii]

Is the controller 240v, 120v, or both? If it's both then you need four wires to the controller; two hots, neutral and ground.

 

[RMessenger]

Is the controller 240v, 120v, or both? If it's both then you need four wires to the controller; two hots, neutral and ground.

It's only 240V.

 

[RMessenger]

I understand that the controller will work on the 3-wire L6-20 plug and outlet, but I'm wondering if I can use the L14-20 plug with the 3-wire cord by simply wiring the three wires to the plug and leaving the ground post alone, that way the outlet in the wall is the preferred 4-wire setup with all 4 wires attached and could be used with other 4-prong appliances.

 

[ingchr1]

Yes, you can put a 4 prong plug on your controller and only connect the 3 wires that it uses. That's how I did mine.

 

[GotPushrods]

I understand that the controller will work on the 3-wire L6-20 plug and outlet, but I'm wondering if I can use the L14-20 plug with the 3-wire cord by simply wiring the three wires to the plug and leaving the ground post alone, that way the outlet in the wall is the preferred 4-wire setup with all 4 wires attached and could be used with other 4-prong appliances.

If you meant to say "leave the neutral post alone", then yes.

If your controller is 240v only, you still want a ground, but won't need the neutral. Don't use the neutral as a ground or your GFCI won't trip as expected, which defeats the whole purpose of having GFCI.

If this is what you meant then ignore this, just making sure.

If the cord you have is 3-conductor, the colors will be black/white/green. You want to wire the black as hot1, white as hot2, and green to ground. You will not have any wire attached to the neutral of the L14-20 plug.

 

[RMessenger]

If you meant to say "leave the neutral post alone", then yes.

If your controller is 240v only, you still want a ground, but won't need the neutral. Don't use the neutral as a ground or your GFCI won't trip as expected, which defeats the whole purpose of having GFCI.

If this is what you meant then ignore this, just making sure.

If the cord you have is 3-conductor, the colors will be black/white/green. You want to wire the black as hot1, white as hot2, and green to ground. You will not have any wire attached to the neutral of the L14-20 plug.

Thanks! Just to be sure, do I still wire all four wires on the 4-prong outlet, then?

 

[GotPushrods]

Thanks! Just to be sure, do I still wire all four wires on the 4-prong outlet, then?

Absolutely. Since the whole point is to have it future-proof, you want it to be fully capable in case you DO ever plug in something that needs all 4 wires.

 

[GotPushrods]

Just to clarify, where is the GFCI in all of this?

Is it before this receptacle we are talking about? GFCI --> receptacle --> brewing panel?

Or will it be receptacle --> GFCI panel --> brewing panel?

If this receptacle is BEFORE the GFCI, I would still run all 4 wires to the GFCI panel, wire it "correctly" for all 4 wires, have another L14-20R after the GFCI panel, then wire as we discussed.

 

[RMessenger]

Just to clarify, where is the GFCI in all of this?

Is it before this receptacle we are talking about? GFCI --> receptacle --> brewing panel?

Or will it be receptacle --> GFCI panel --> brewing panel?

If this receptacle is BEFORE the GFCI, I would still run all 4 wires to the GFCI panel, wire it "correctly" for all 4 wires, have another L14-20R after the GFCI panel, then wire as we discussed.

The GFCI is in the main panel (I got a 20 amp GFCI breaker). I wired the L14-20 receptacle correctly (all 4 wires) and skipped the neutral on the L14-20 plug attached to the controller cord.

 

[jeffmeh]

The GFCI is in the main panel (I got a 20 amp GFCI breaker). I wired the L14-20 receptacle correctly (all 4 wires) and skipped the neutral on the L14-20 plug attached to the controller cord.

Sounds good. Congrats. How is it working out?

 

[RMessenger]

Sounds good. Congrats. How is it working out?

Great. I finally finished putting everything together yesterday. I couldn't have done it without the help from folks here. Thanks!