Simple wiring help needed with spa panel and 3 wire 240 - no neutral

harfordhawk 2018-08-24 18:57:48 UTC #1

I have read and read, and I just get so confused! I am building a simple 5500 watt kettle. Have spa panel for the gfci breaker and have 220 v 3 prong outlet in garage. I checked wires coming to outlet and it is ONLY 3 wires 2 hots and a bare copper ground.

My confusion is wiring the spa panel. Where does ground on incoming attach? neutral bar or ground bar?

where does outgoing ground to kettle attach? neutral or ground? or breaker neutral?

some sites says connect neutral and ground in spa panel, others say do not do that! Which is true?

I am attaching pigtail from breaker to neutral bar. I think that is correct but not sure.

Thank you so much for helping me. I would assume this has been answered 100's of time, but I cannot find those answers.

sneezles61 2018-08-24 20:07:17 UTC #2

Now, I'm not licensed electrician, but heres my 2 cents... The 3 wire system was all good for many years... The newer codes call for 3 wire PLUS a ground...
The wire used for neutral is also a ground.. Once in the panel, they land in the same buss, BUT, with a GFCI, the neutral wires into the GFCI's neutral leg... IT HAS TO BE ABLE TO TRIP IF THERES EVEN A MILI-AMP OF VARIATION.
If it was mine to do, I'd up grade the wires from the panel to the spa box with the 3 plus ground. So the wiring is 2 hots and the neutral, the ground to the chassis...
So on your kettle hook up/connector neutral is ground or vise versa, if you wish... Please, do use a tester once you've made your connections and do test it... Even give a quick spray of water to the connections... That will test the GFCI! I did that with mine, kinda accidentally... It tripped as it should... You can look at the brew gear, electric kettle build up.. Sneezles61

harfordhawk 2018-08-24 20:16:11 UTC #3

thanks for replying.. running a new 240 line is not easy... at all... the receptacle I was planning to use is a 3 wire for a welder. main panel is in garage so I guess I 'could' run a line which would be temporary ( removable when I sell the house) .. but what a pain that would be...

still it seems when I bought all this stuff, there was many saying 3 wire 240 was aok as long as I didn't want to split off 110 somewhere , which I do not. now it seems I NEED that neutral wire which is not there.

thanks again for your help. I will continue to solicit ideas if there is a way to safely use 3 wire 240 to a heating element thru a spa panel ( to utilize the GFCI breaker), so anyone who has done that please chime in... thanks

harfordhawk 2018-08-24 22:26:42 UTC #4

For information to anyone seeing this thread. I am pretty sure I found an answer and certainly use a 4 wire receptacle if at all possible, but it seems this should work for a 3 wire only.
see answer in this thread. https://www.homebrewtalk.com/forum/threads/spa-panel-gfci-3-wire-source-to-3-wire-appliance-is-it-doable.652555/

sneezles61 2018-08-25 01:23:34 UTC #5

If you are confident, then do that... I feel that there is too much at stake to cut corners... Sneezles61

harfordhawk 2018-08-25 01:31:14 UTC #6

thank you. I do not consider it cutting corners so I agree with you. Life and health is way more important than electric brew setup.

squeegeethree 2018-08-25 11:42:15 UTC #7

Too early to read in full but my cursory glance looks like you are trying to hook up a 3 phase appliance to a 2 phase run. I would recommend you use the proper 3 phase breaker and wire for 3 phase as intended by the manufacturer.

hd4mark 2018-08-25 12:38:53 UTC #8

I'm not familiar with a spa panel but I believe a GFCI does not need a ground to operate properly. The test/reset buttons should work.

That said, is wiring in place through a conduit? If so is it possible to pull another wire of the same gauge to add the neutral? Our condo is wired with metal conduit using the conduit as ground. I went trough similar problems wiring a bath fan. After a lot of fooling around I finally pulled a new hot lead to separate the light and fan that were originally wired together.

harfordhawk 2018-08-25 12:59:24 UTC #9

I think you are correct about the gfci not needing a neutral to function properly, but I plan to test it after all is built. Sadly, no, the wiring to the outlet was not pulled thru a conduit so that is why it would be difficult to bring in another wire. I think based on a few 'experts' in the homebrewtalk thread, that this will work fine. If you think about it , 220 volt hot water heater sticks have only 2 hots and a ground, no neutral, and I suppose they are safe since we use them all the time in hot water heaters... I know it might be apples and oranges, and some electrician would be able to explain the differences but what I really wanted was a GFCI in the loop that would function and I am pretty certain that will be the case.

Rburrelli 2018-08-25 15:52:51 UTC #10

GFCIs work by sensing current on the neutral wire. I would think it would be required to be there in order to protect properly.

Rburrelli 2018-08-25 15:55:08 UTC #11

Not the case. Two hots, a neutral and a ground is single phase 240volt.

harfordhawk 2018-08-25 16:18:53 UTC #12

240 V GFCI compare voltage between each hot leg , the way I understand it. yes 110 V gfci would be comparing hot to neutral

sneezles61 2018-08-26 15:12:28 UTC #13

I wired in a 220 volt GFCI breaker when I did my build up... It did need the neutral to work.
See the older 2 wires and a ground was deemed acceptable back during WW2, because of the need for copper in the war efforts. So, we've been using this for a long time. Lately, as more safety requirements are placed upon us, 2 hots, a neutral and a ground are being implemented.. That being said, the old style isn't being required to change, rather phase it out...
I've not tried this, but, land your ground to the neutral spot on the GFCI breaker... test it... Be careful... I don't want to hear of someone being electrocuted for a brew... Sneezles61

harfordhawk 2018-08-26 15:34:04 UTC #14

I have read and read and I understand the GFCI does not need the neutral in a pure 220 volt system, so I will go with that will wire ground to ground. Old hot tubs even have 3 wire systems and GFCI and they are protected fine without a neutral,

Rburrelli 2018-08-26 17:57:06 UTC #15

Please be sure about your voltage system. It is not likely to be a pure 220 volt, but probably120/208 volt. Clarify that before proceeding.

harfordhawk 2018-08-26 18:24:00 UTC #16

thanks yes it is 240 volts... 2 120 hots and a ground. I am plugging to a receptacle that was meant for a welder, spa box will plug in there.

GoBlue59 2018-08-30 21:16:00 UTC #17

I’m an electrical engineer so hopefully I can help if you still need it. Unfortunately in residential applications, most 240vac comes from running two different 120vac feeds with no neutral. It’s not the most elegant solution, but alas it works (I won’t get into the details of how/why it works or why I don’t like it)

Since both wires are hot, there is no neutral, nor a need to wire to a neutral. Each wire is 120vac of potential between hot and neutral. But the two hots are separated by 240vac, so basically one of them acts as the return for you.

Long story short, the ground/bare wire goes to ground, not neutral. There is a good chance your neutral bar is also grounded anyways, so it would all be the same, but ideally the bare wire always connects to the ground bar

harfordhawk 2018-08-30 21:26:13 UTC #18

Thanks for your reply. That confirms my research. I am an engineer as well, but not electrical...

After I wired it all up the breaker would not set and I am chalking it up to a bad breaker at this point, so i will get another breaker and see what's up. Thank you for helping confirm my plans. I do not plan to bring off a 120 circuit or anything so I think I should be good with a pure 220.. Both hot legs go to the heating element as well as ground.. There really is no place for a neutral to go anyway.

GoBlue59 2018-08-30 21:56:15 UTC #19

Exactly. I made an electric beer brewing kettle, 240vac... and it’s just 2 hots and a ground.

If the breaker trips immediately it could be a bad breaker but it could also be a swapped/ground fault. Not second guessing your wiring, but sometimes a frayed wire internal to the equipment brushed up against a ground. Just food for thought if a new breaker also doesn’t work... I have also often accidentally wired pin 1 on a plug to pin 2 on the equipment. Also since it’s water equipment, who knows if the water is shorting a terminal. Hot tubs often have a high inrush of current too, not sure if it’s appropriately sized for the amperage.

So there are many possible culprits. Good luck, be careful!

harfordhawk 2018-08-30 21:59:54 UTC #20

yeah GFCI trips with no load wires connected. standard 2 hots and ground coming to breaker..