240V with no neutral? Can I build a rig?

[wyzazz]

A GFCI breaker works by monitoring the difference in current between hot and neutral, regardless if it's 240v or 120v.
http://www.ehow.com/how-does_4898026_gfci-circuit-breaker-work.html

That is how it works. GFCI breakers have pigtails for a reason. They will not work without connecting the neutral from the receptacle to the breaker.

GFCI CORDS are different. I have no say on that. But GFCI BREAKERS must have the neutral connect to work. I was merely disputing the statement that he said it monitors both hots to check for current differences.

I don't see where SOB said anything about a GFCI Breaker where you quoted him, he simply said GFCI.

This is my understanding of how things work. Yes a 240V GFCI Breaker has a neutral pigtail and yes you need to wire that up to make a 240V GFCI Breaker work, but it does not use that neutral line to trip the GFCI. Fundamentally 240V power works differently than 120V. 240V uses 2X 120V "hot" lines to provide power, a GFCI in that instance monitors those lines for any imbalance and trips if an inbalance is found. 120V uses a 120v "hot" and a neutral, a GFCI in this instance will monitor the hot and neutral for any imbalance.

Someone with more electrical knowledge than myself may chime in and tell me to stop pushing propaganda, but this is my understanding of how this works.

 

[bbognerks]

Ah after reading that thread, I see where you wouldn't need a neutral. They make 2 pole GFCI breakers that don't have a neutral input and they just monitor the hots. But with this type, you can't break off into a separate 120v leg inside your control panel. I stand corrected somewhat, but for the breaker in the HD spa panel, you still must have the neutral for it to work.

 

[wyzazz]

Ah after reading that thread, I see where you wouldn't need a neutral. They make 2 pole GFCI breakers that don't have a neutral input and they just monitor the hots. But with this type, you can't break off into a separate 120v leg inside your control panel. I stand corrected somewhat, but for the breaker in the HD spa panel, you still must have the neutral for it to work.

Correct! You need to have that neutral on the line side for that GFCI breaker to work.

 

[bbognerks]

There I go again, making an ass out of myself by assuming he meant the GFCI breaker included with the HD Spa panel. Sorry for any confusion. I just wanted to share my experience with wiring in the spa panel breaker. It had me scratching my head for a bit trying to figure out why it was still tripping when all my wiring looked good inside my control panel.

 

[petey_c]

P-J, I was talking about him running a spa/sub panel. 250.130 (C) is for receptacles. If he wanted to add a ground to his 120 or 240 circuit, that would be okay. Most of the older type 240 VAC circuits I've run into (here in NY) have been using SE type cable. Two hots and an uninsulated wire that acted as the neutral. That's because the loads balanced out and there was no current on the neutral. You can't just decide to use an uninsulated conductor to start carrying current. It's hard to debate this point when we don't know what type of wiring we're talking about. I’m only familiar with what I’ve seen here. I did however, recently see a dryer run off of 10/2 SJ (?) cord. Black and green as the current carrying conductors and white tied to the neutral/ground bus (probably not a licensed job...). If that wire had been black, white and red I could’ve fixed it easily, but I had to run a new 10/3. (okay I’m starting to drift toward ECN/Mike Holt territory here…) I know that there’s also an exception if the building is detached or not, but I’m suffering from midnight shift dementia right now. What do you do in NC? pete

 

[magnj]

You guys have been busy since I last checked in! Unfortunately I did not make it to my friend's house, blizzard. But when I do I'm going to turn the circuit off and check out the wire, we can go from there I guess. How do I know if the third wire is being used as neutral or ground?

 

[wyzazz]

How do I know if the third wire is being used as neutral or ground?

If there are only 3 wires then it's being used for a ground. If it's uninsulated it should only be used as a ground, if it's insulated you can use it as a neutral and run another ground. If there are 4 wires then the White one is a neutral & the bare one or green one is a ground.

 

[magnj]

Thank you for that incredibly concise answer! Seriously.

 

[wyzazz]

Just reciting what I've learned by researching for my own future build.

 

[magnj]

Thanks for all the help guys. However because of my lack of electrical knowledge and the costs, I think I'm going to end up going with a 120V setup to just maintain mash temps and use propane to do major heating and boiling.

 

[wyzazz]

Hang around here a little longer, you'll get the hang of this stuff in no time. In the meantime there is certainly nothing wrong with propane.

 

[Ohio-Ed]

Thanks for all the help guys. However because of my lack of electrical knowledge and the costs, I think I'm going to end up going with a 120V setup to just maintain mash temps and use propane to do major heating and boiling.

I think that is a great plan and one you can make very portable.
You can run a 1500watt rims heater AND a march pump on a 15amp outlet... you can always find a place to plug it in.

Ed

 

[magnj]

Thanks, it's not even so much that I couldn't figure it out as I don't want to half ass it. I don't own my own space, but I think I will be able to get a 20 amp gfci 120V breaker in my box and run an extension cord to where I brew, should be enough to maintain mash temps.

 

[magnj]

Thats true, how many watts do you think I need to maintain mash temps in an aluminum kettle outdoors in the winter? I know I could use a cooler but they are already purchased.

 

[petey_c]

magnj, Instead of using a 20A GFCI breaker, you could use a standard 20A breaker, then put a 1900 box and a 20A GFCI and duplex receptacle (4 outlets all together) at the end of a 20A extension cord. The GFCI, outlet, 1900 box and cover will cost you less than a 20A GFCI breaker and still provide you with GFCI protection. Plus it can be easier to wire, especially if the panel is kinda full.

 

[magnj]

I will take that into consideration, thanks. I actually just ordered a 1500W element so I'll probably do this all on 15a and just use a plug and play GFCI at the outlet for even more flexibility.

Now I'm trying to figure out what I need/want out of the control box. Basically just the element and the pump, maybe an emergency stop and an on/off override for the pid?

 

[petey_c]

magnj, This is where my knowledge ends. I'm a electrician (mostly residential) who's becoming a brewer, not the other way around. My experience with electric brewing stops at my stove...

 

[CodeRage]

I only read the last two pages, so forgive me if I miss something beforehand.

You can use a 240GFCI breaker, even one that has a neutral pigtail, on a 240V service that does not have a neutral.

However, you can not use the neutral on the GFCI. It will be strictly a 240V circuit, and you will still have GFCI protection.

You could use this circuit to power your heating elements then run a secondary 110VAC circuit for your controls (PID, Brewtroller, BCS, relays, what have you).
This is what I did with my brewery at first when I was using the dryer's 240V service which had no neutral.

The important thing to remember is to not mix the line and neutral from the 110 circuit with the 2 lines from the 240V circuit. For example never use the neutral with one of the lines from the 240V to get 110.

I see your renting, so you could pull power from your range(is it electric?) or dryer with the appropriate cable, tied that into the supply side of a spa breaker and then use the load side of the spa breaker to provide power to your elements.

Then an extension cable plugged into an outlet will give you your 110. If it isnt a gfci outlet you could put a gfci outlet in a single gang box, wire the supply side to the extension cord and the supply side to your controls and you'll be good.

 

[magnj]

Thanks CodeRage, but I decided to go 120V RIMS and propane burners for now. I think it will be cheaper, portable, and less likely that I F* something up.

 

[jflimbo]

Code rage,
I'm am currently setting up a system similar to what you used with a separate 110v and 240v. I'm using a HD spa panel with GFCI. The breaker has a neutral pig tail which I understand I do not need in order to be gfi protected. The question is what to do with the pig tail and the ground from my rig. Do I just secure the pig tail to the neutral bus which goes no where. Then secure the incoming neutral (used as ground) and the ground from my kettle to the ground bar in the spa panel? I think this is correct. Anyone chime in please.

 

[DeafSmith]

Code rage,
I'm am currently setting up a system similar to what you used with a separate 110v and 240v. I'm using a HD spa panel with GFCI. The breaker has a neutral pig tail which I understand I do not need in order to be gfi protected. The question is what to do with the pig tail and the ground from my rig. Do I just secure the pig tail to the neutral bus which goes no where. Then secure the incoming neutral (used as ground) and the ground from my kettle to the ground bar in the spa panel? I think this is correct. Anyone chime in please.

I assume you are only using the spa panel for 240 volts with no neutral output. In that case, see post #7 above for how I wired mine. AFAIK, the pigtail has to be tied to neutral/ground in order for the GFCI breaker to function.

 

[jflimbo]

Thanks DeafSmith,
Yes I'm using 240 with no neutral. 3 prong dryer. Your solution works for my setup.
As a side note does anybody know of a reliable method to test a 240 gfci. I use a hand held tester for my 120 circuits. The type that plugs in press the button and, if wired correctly, the gfi pops. Is there a similar device or method to test a 240 gfi?
Thanks all

 

[wyzazz]

Doesn't it have a test button?

 

[Walker]

I assume you are only using the spa panel for 240 volts with no neutral output. In that case, see post #7 above for how I wired mine. AFAIK, the pigtail has to be tied to neutral/ground in order for the GFCI breaker to function.

The pigtail doesn't have to be tied to anything to make the actual GFI work, but it might need to be tied into the panel's neutral in order for the TEST button on the breaker to work.

 

[jflimbo]

Doesn't it have a test button?

Yes the breaker has a test function. I guess I should have expanded on my question. I wonder if there is a tester that works at the end of the circuit not at the breaker. I'm not sure of the exact function of the test on the breaker. What exactly is it testing. In the end what I would really like to be testing is if at the termination of my wiring (kettle element) if something has the potential to leak current is the gfci going to trip. I believe that is essentially what the 120v hand held tester does.

 

[Walker]

Yes the breaker has a test function. I guess I should have expanded on my question. I wonder if there is a tester that works at the end of the circuit not at the breaker. I'm not sure of the exact function of the test on the breaker. What exactly is it testing. In the end what I would really like to be testing is if at the termination of my wiring (kettle element) if something has the potential to leak current is the gfci going to trip. I believe that is essentially what the 120v hand held tester does.

The test button on the breaker creates a path (via a high impedance resistor) from one of the hot lines to neutral, but that neutral path bypasses the GFI detector. This creates a situation where the GFI sees current going into the system on one of the hot lines, but not coming back out on the other hot line or the neutral. GFI trips.

You can test GFI at the outlet by putting a 120V tester into action. Put one end in one of the hot ports and put the other end in ground. That creates a 120V circuit, from hot to ground, which will trip the GFI.

 

[DeafSmith]

The pigtail doesn't have to be tied to anything to make the actual GFI work, but it might need to be tied into the panel's neutral in order for the TEST button on the breaker to work.

I assumed it was necessary because the instructions that came with the panel called for it to be connected and because with the instructions there are 3 connection diagrams - the third one shows the connection for 240v output only with no neutral output, but shows the pigtail connected to the incoming neutral. I never tried to see if it would work without the pigtail hooked up.

 

[Walker]

I assumed it was necessary because the instructions that came with the panel called for it to be connected and because with the instructions there are 3 connection diagrams - the third one shows the connection for 240v output only with no neutral output, but shows the pigtail connected to the incoming neutral. I never tried to see if it would work without the pigtail hooked up.

GFI does not care how many wires you have involved. It can be a hot and a neutral (standard 120V), two hots (240V w/o neutral), two hots and a neutral (240V w/ neutral), or 13 hots and 7 neutrals (?).

All the GFI does is watch the current flowing in and out of the system across all of the wires present. If the sum of current going in matches the sum of current coming back out, then the GFI knows that all is well and power stays on.

If it ever sees a different between current in and current out, then it will cut the power.

If your neutral isn't connected to anything, the GFI will still work. Nothing will be flowing in or out on the neutral line, and the GFI will just be ensuring that the two hot lines have equal and opposite currents.

BUT....

The "test" button on the breaker MIGHT be making use of the neutral for it's functionality, so you would need the neutral connected (pigtail to panel) in order for that button to work.

 

[DeafSmith]

GFI does not care how many wires you have involved. It can be a hot and a neutral (standard 120V), two hots (240V w/o neutral), two hots and a neutral (240V w/ neutral), or 13 hots and 7 neutrals (?).

All the GFI does is watch the current flowing in and out of the system across all of the wires present. If the sum of current going in matches the sum of current coming back out, then the GFI knows that all is well and power stays on.

If it ever sees a different between current in and current out, then it will cut the power.

If your neutral isn't connected to anything, the GFI will still work. Nothing will be flowing in or out on the neutral line, and the GFI will just be ensuring that the two hot lines have equal and opposite currents.

BUT....

The "test" button on the breaker MIGHT be making use of the neutral for it's functionality, so you would need the neutral connected (pigtail to panel) in order for that button to work.

Yes, I know it's just looking for the total current in all wires which go through the GFCI to be zero, tripping when that is not true, but I thought perhaps the GFCI needed the neutral for its own internal circuitry - possibly to get DC power for that circuitry, though of course they could use a full wave bridge from the two hot lines and not need the neutral. As I said, I didn't bother to try it without the pigtail hooked up.

 

[Walker]

I thought perhaps the GFCI needed the neutral for its own internal circuitry - possibly to get DC power for that circuitry

Yeah... possibly. never considered that part. I say hook it up.