3 Prong 240 Outlet wiring question

[wedge421]

My old system used a 4 Prong plug and socket. With the new system It is a 3 wire power cord so I needed to change the socket to fit the plug. With the new socket I combined the bare copper and the white together and placed them in the neutral on the socket. This kept causing my 30 amp GFCI breaker to trip. My questions is can I just leave the bare copper wire unhooked from the receptacle? And if so should I electrical tape/wire nut it?

 

[AknotOtoads]

The green screw terminal where you have your neutral connected is for the ground "bare wire". If you ground your neutral the GFCI will continuously trip.

 

[wedge421]

Actually as that is wired in the picture the GFCI does not trip. Should I put the copper in the ground slot and put a wire nut on the white and not connect it?

 

[AknotOtoads]

The red wire is 110V the black wire is 110V, the white wire is the neutral. That needs to be hooked up to complete a circuit. Unless its connected to a sinking source that allows the current to flow.
A typical 3-wire 220V connector will have a connection for the red white and black wires and then the ground is just screwed into the side.
Do you have a picture of the complete back of the socket?

 

[Epimetheus]

The white should be connected to whatever screw corresponds to the neutral hole in the socket. Check the outlet with a multimeter to see if the neutral hole goes to the green screw. Get a multimeter if you do not have one.

The ground wire should then be connected to the metal box with a grounding screw. The "bump" in the back of the box is designed to receive a grounding screw. it is best to use a green grounding screw which has threads to match the box. A sheet metal screw is not as secure. It is difficult to wrap a heavy wire around a screw. You can crimp an eyelet onto the wire.

I do not see a cable clamp, perhaps it slid down out of sight. Please use a cable clamp to prevent the cable from abrading on the sharp punched hole.

The 240v wire appears to run down the wall without protection. Please consider using plastic or metal conduit, or metal wiremold or even fasten a 2x4 to the wall and run the wire down the side of it with staples every 2 feet. The 2x4 is not code but it will at least prevent stuff from banging into the wire. Sh**t happens, you know?

Why change from the newer 4 prong design to the older 3 prong?

 

[wedge421]

THe receptacle is a L6-30 it has spots labeled G,X,Y i have the black and red in the X and Y. Should I hook the white up to the G or the bare copper? And if the bare copper should I just wire nut the white without an issue?

 

[wedge421]

The white should be connected to whatever screw corresponds to the neutral hole in the socket. Check the outlet with a multimeter to see if the neutral hole goes to the green screw. Get a multimeter if you do not have one.

The ground wire should then be connected to the metal box with a grounding screw. The "bump" in the back of the box is designed to receive a grounding screw. It is difficult to wrap a heavy wire around a screw. You can crimp an eyelet onto the wire.

I do not see a cable clamp, perhaps it slid down out of sight. Please use a cable clamp to prevent the cable from abrading on the sharp punched hole.

Why change from the newer 4 prong design to the older 3 prong?

My issue for going from 4 to 3 was that the new system has a 3 wire cord. Am I able to use a 4 prong plug on a 3 wire? And if so how is that wired?

 

[AknotOtoads]

Here's this...

 

[wedge421]

Here's this...

Im using the L6-30 though.

 

[Bobby_M]

Guys.. 3 wire 240v uses Hot/Hot/Ground with NO neutral. If your system requires a neutral to derive any 120v circuits, then you have the wrong cord.

 

[mux]

First off get a fitting for that cable! That gfci breaker requires a neutral to work properly. Make sure you have wired correctly in the panel. Your 2 pole receptacle requires each phase and earth. If your tied into the main/only panel in the system this neutral and ground are the same thing.

 

[mux]

Bobby is correct, but you still need a neutral for that gfci to work.

 

[AknotOtoads]

Yeah, that's the nema 6-30. Its pretty much the same.
I would probably just leave it as you have it. Having the neutral as the ground with a gfci breaker would probably be the safest, at least it will work if it has too...i think! LOL!!
The system i just wired in is a four wire system with a 50 amp gfci. I have one dedicated leg for everything i need.

 

[Epimetheus]

Guys.. 3 wire 240v uses Hot/Hot/Ground with NO neutral. If your system requires a neutral to derive any 120v circuits, then you have the wrong cord.

I stand corrected. The bare ground goes to the G screw. The white wire is no longer used and is capped off in the box with a wire nut.

Bobby_M, thank you for the correct wiring.

 

[P-J]

NEMA 10-30 and NEMA 10-40 have 2 hots and neutral - no ground.

 

[Epimetheus]

I will defer to an electrical forum with answers from electricians. If an electrician here replies, I will defer to them.

See discussion on using a GFCI breaker with a 3-wire system on the Mike Holt electrical forum.
240 volt 3-wire pool pump hookup

"The GFCI will need to be connected to the line neutral to function properly but there need be nothing connected to the "load neutral" terminal. "

In other words, there is a white wire from the GFCI breaker to the buss in the breaker box. There is no white wire from the GFCI to whatever you are running.

For reasons why, review the thread in its entirety.

I am stepping out of this. I do not feel good replying without personally having done this. I have wired appliances with 4-wire without a GFCI.

 

[wedge421]

NEMA 10-30 and NEMA 10-40 have 2 hots and neutral - no ground.

PJ, so if I install the bare ground and cap off the white will the GFCI no longer serve its purpose? And its looking for and more like I should just go back to the 40 prong receptacle so that all of the wires are used. But if I do that am I am to wire a 4 prong plug to the 3 wire power cord and still have the GFCI be functional?

 

[P-J]

My old system used a 4 Prong plug and socket. With the new system It is a 3 wire power cord so I needed to change the socket to fit the plug. With the new socket I combined the bare copper and the white together and placed them in the neutral on the socket. This kept causing my 30 amp GFCI breaker to trip. My questions is can I just leave the bare copper wire unhooked from the receptacle? And if so should I electrical tape/wire nut it?

PJ, so if I install the bare ground and cap off the white will the GFCI no longer serve its purpose? And its looking for and more like I should just go back to the 40 prong receptacle so that all of the wires are used. But if I do that am I am to wire a 4 prong plug to the 3 wire power cord and still have the GFCI be functional?

So from me - I have a question for you. You had a 4 wire system and a 4 wire outlet avaiable for your use. Your built your new system using a 3 wire power cord but this new system still needs a 4 wire power input (2 hots, neutral & ground) to properly function. Now: Why did you choose to use a 3 wire power cord in the new system.

Change the power cord to a 4 wire that matches your original outlet.!!!

Problem solved.!

Edit: Again - A 4 wire outlet and a 4 wire plug with a 4 wire cable to your controller.

 

[MercMan]

Or just buy a in-line GFCI from these guys and don't worry about installing a spa panel with a GFCI breaker.
http://www.nssltd.com/

 

[DocnSun]

The green lug is ground. Any ground should go to this lug.