L6-30 receptacle and GFCI wiring question

[Mike_kever_kombi]

I am in the process of getting the electric run for the new brew space.

I have my spa panel ran and wired, and am in the middle of wiring receptacles for controller.

I have a 3 vessel controller from SS Brewtech and it comes with L6-30 plugs from the factory. For the L6-30 receptacles there are only 2 spaces for hot and 1 space for ground.

Do I use the neutral (from spa panel) for the ground leg (on receptacle), and the ground (from spa panel) to receptacle box and ground box (it's an exterior use box) in order to maintain GFI function?

 

[Mike_kever_kombi]

I found a couple places online that say the neutral is not needed unless it's needed i.e. 110v

So I wire nutted the white neutral and connected the ground to receptacle. I have not plugged in the control panel yet.


If anyone has info one way or another I welcome the feedback. I am more apt to accept the info from here than from Tony the electrician/barber on YouTube.

Thanks.

 

[Dland]

Separate neutral is not needed to run panel if no 120V, but I think you need both ground and neutral for GFI to function properly. Not sure on that, but something to look into. I think the GFI works by comparing ground to neutral.

What I might do is run the two hots and neutral in the 3 wires and run a separate ground from spa panel to brew control. Your 3 prong elements may not be GFI protected, but panel and controller will be.

In practice, ground and neutral are often confused, but ground and neutral should really be separated until final ground to neutral bond in the main panel. There is "supposed" to be only one ground/neutral bond in any given service. (knowledge mainly acquired playing with large generators, I am not an expert on brew controllers).

 

[bgmac]

This is a common question if you search. If you are not running a 110 volt component from the 240 outlet then a neutral is not required. Yes hook the receptacle ground wire to the ground bar in the panel. Do you have a picture of the panel wiring?

 

[Mike_kever_kombi]

This is a common question if you search. If you are not running a 110 volt component from the 240 outlet then a neutral is not required. Yes hook the receptacle ground wire to the ground bar in the panel. Do you have a picture of the panel wiring?

Spa panel or control panel?

The control panel is sealed from factory and just has a molded plastic L6-30 plug.

The spa panel has the 2 hots from main panel breaker going to the hot bus bar in spa panel. The neutral and ground go from main panel bus bars to their respective bus bars in spa panel. The GFI breaker has 2 hots that go to L6-30 receptacle (for control panel) and the white pig tail that goes to neutral bus bar. The ground bus bar wire goes to the receptacle.

I'm fairly confident that the spa panel wiring is correct. The main breaker does not trip, and the gfi breaker trips when test button is pushed. The receptacle has power.

I just was not sure about neutral wire, but it appears that it is not needed.

 

[doug293cz]

The GFCI will work without a neutral on the load side , as long as the pigtail from the GFCI is connected to ground or neutral upstream (preferably source side neutral if it exists, but ground if no neutral) of the GFCI breaker. The fact that your Test button works indicates that it is probably connected correctly. Can you post a picture of your spa panel wiring for verification?

A GFCI works by measuring the vector sum of all the currents, in all the wires, running thru the GFCI (internally all the wires run thru a single current sensing coil.) By vector sum, I mean taking into account the current direction on each wire. In a 240V only system, the same current flows on each hot wire, but in opposite directions, so the vector sum of currents is 0. In a 240V/120V system you can have different currents on all three wires, but the sum of one hot and the neutral will have equal and opposite current to the other hot, so again the vector sum is 0. If for some reason, all the currents don't add up to 0 (within ~0.005A) then the GFCI trips. Currents not adding up usually means some current is leaking somewhere it shouldn't.

The Test button works by diverting a small amount of current to neutral (or ground) before it reaches the sensing coil. This causes the currents thru the coil to no longer add up to 0, and the GFCI trips.

Brew on

 

[bgmac]

Mike, a picture of the Spa panel wiring. Like doug said, no neutral is required for 240 volt on the load side. Just the 2 hot legs and a ground. You should only need a neutral if the control panel is using 1 hot leg of the 240v to power a 110v item like a pump or fan etc... That's why you see a 4 prong plug (2 hot legs, ground, neutral) for most electric dryers and ovens since they have 110v components such as the control panel, fans and lights. But, if the factory plug on your control panel only has 3 prongs, then its just the 2 hot legs and ground so no 110v items I assume. Sounds like the GFCI breaker is wired correctly as doug stated since it trips when tested, meaning the neutral wire in the panel is installed either to a neutral bar, which is code or ground bar.

 

[downzero]

The GFCI will work without a neutral on the load side , as long as the pigtail from the GFCI is connected to ground or neutral upstream (preferably source side neutral if it exists, but ground if no neutral) of the GFCI breaker. The fact that your Test button works indicates that it is probably connected correctly. Can you post a picture of your spa panel wiring for verification?

A GFCI works by measuring the vector sum of all the currents, in all the wires, running thru the GFCI (internally all the wires run thru a single current sensing coil.) By vector sum, I mean taking into account the current direction on each wire. In a 240V only system, the same current flows on each hot wire, but in opposite directions, so the vector sum of currents is 0. In a 240V/120V system you can have different currents on all three wires, but the sum of one hot and the neutral will have equal and opposite current to the other hot, so again the vector sum is 0. If for some reason, all the currents don't add up to 0 (within ~0.005A) then the GFCI trips. Currents not adding up usually means some current is leaking somewhere it shouldn't.

The Test button works by diverting a small amount of current to neutral (or ground) before it reaches the sensing coil. This causes the currents thru the coil to no longer add up to 0, and the GFCI trips.

Brew on

I actually had no idea about how a 240 volt GFCI would work since I've never installed one, but that makes perfect sense.

For the others, GFCIs work by verify that what is coming on one side of the circuit is leaving on the other (and therefore, hopefully, not through your body and back to the earth!).