Heating Elements and GFCI

My HLT and BK each have standard 240v 4500w elements attached to 3 wire dryer cord (two hots to the element, ground to the keggle). I had an electrician over to add a 240v outlet near my brewstand, and asked him to put in a 30A GFCI breaker in the panel, upstream. He said, yeah sure, but without a neutral, the GFCI won't do you any good. Based on my (minimal) understanding of GFCI breakers, he's right.

So, my question is, if that's the case, why does everyone seem to feel that a GFCI breaker is helpful in a setup like this?

peace of mind I believe I just talked to a Electrician Company Owner today that is a customer of mine he said its pointless.. after I get My controller he said he would show me how the correct way to wire it up using 2 circuits a 120v and 220v for the element.. no gfci and safe.
I'll post a diagram after I see how its done right, might be a week

Thanks Hank9, I'll look forward to seeing your diagram!

It is my understanding that if the current on the 2 hot legs of a 220v GFCI breaker aren't equal that it trips. The only way (I think) to trip a non-GFCI breaker would be to exceed its rated current... So I'm guessing that a non-GFCI breaker would trip once it exceeded its rated current to ground, hopefully not in a path through you.

They must be required in wet areas for a reason I would think.

I'm not an electrician, but I have a deep respect for the dangers of electricity.

I found this here... and it sounds correct to me:

GFCI protection works on detecting any current that does not return through
its intended path. With a single pole breaker, this means measuring the
current through the hot and the neutral to detect a difference. With a two
pole breaker, current in one hot must return through either the other hot,
or the neutral, or split between the two. GFCI protection involves measuring
all three to make sure everything works out even.

I really don't think that skipping GFCI is the best place to pinch pennies on a project involving large amounts of liquid and electricity.

Both of you need new electricians. Because either they want to kill you, or they do not know much about GFCI.

You do NOT need a neutral for a GFCI to work

YOU CANNOT get the same protection as a GFCI, without a GFCI

This is a scary thread.

Good luck!

I bought my house in 2000, from a guy who's brother is an electrician. The electrician brother did a lot of half-assed stuff in this house that wasn't up to code. He installed the hot tub on a non-GFCI circuit.

I was left to think that some electricians get a little overly cocky when it comes to electrical safety. Surely not all, but any electrician who views GFCI as "peace of mind" would fall in to that category in my book. You don't read a lot about people being killed by standard household electrical current, but it happens quite a bit.

This is just amazing to me, it is like a train wreck. I hope they both get new electricians.

How a GFCI works:

http://www.codecheck.com/cc/gfci_principal.htm

**I'm not an electrician** You should only believe the first line after this:
Install the GFCI.

In the above link, regarding 220v GFCI function, it says:
"GFCIs for 220 VAC applications need to monitor both Hots as well as the Neutral. The principles are basically the same: the sum of the currents in Hot1 + Hot2 + Neutral should be zero unless a fault exists.

To detect a grounded neutral fault, a separate drive coil is continuously energized and injects a small 120 Hz signal into the current carrying conductors. If a low resistance path exists between N and G downstream of the GFCI, this completes a loop (in conjunction with the normal connection between N and G at the service panel) and enough current flows to again trip the GFCI's internal circuit breaker."
You can also reference the WIKI Here:

From my research:
On a 3 wire 240v circuit, the GFCI measures H1 + H2, and compares it to Neutral. That's why it won't trip when you have 15 amps on one leg and 20 amps on the other.
If you touch H1 and Neutral, you'll add to that load. H1 + H2 - Neutral still = 0, and the GFCI May not trip. This is bad

THIS is the important part:
If your body is the short between H1 OR H2 to GROUND (This is Earth! Or you touch anything - grounded metal/conduit/shelf/anything else near your rig), you cause a ground fault. Even on a 3-wire 240 circuit. The GFCI trips. This could save your life, and for that alone it's worth installing one.

Just do it.

I can see the eulogy... "He spent $2187 on the brew rig, and $7 on the breaker"

Thanks everyone for your resoponses. Just want to make one thing clear: I'm not trying to save $$$ by not putting in a GFCI breaker. I take safety very seriously. My concern is that, if a neutral is required for a GFCI to work, adding one to my setup would simply provide a false sense of security, which is dangerous in and of itself. If a GFCI will work with a three-wire setup, I will definitely put one in.

I discussed this at length with my electrician, to make sure I understood what he was saying. He actually called another electrician in his office to double check his knowledge, and they both agreed. Given your responses, I'm going to continue to research this, though.

willynilly said:

Both of you need new electricians. Because either they want to kill you, or they do not know much about GFCI.

You do NOT need a neutral for a GFCI to work

YOU CANNOT get the same protection as a GFCI, without a GFCI

This is a scary thread.

Good luck!

Click to expand...

Sorry to disagree, but a neutral is essential for a GFCI. A GFCI monitors the currents in the hot and neutral wires.

Marsdude said:

Sorry to disagree, but a neutral is essential for a GFCI. A GFCI monitors the currents in the hot and neutral wires.

Click to expand...

It monitors incoming and outgoing current... This can be done without a neutral in a straight 240VAC circuit, as it is done on heating elements, hot tubs etc...

How many 240VAC heating elements have YOU seen with a neutral wire? Hot tubs?

Maybe this will help...

There are two types of two pole GFI breakers, straight 240 volt, with no neutral lug, and 120/240 volt with a neutral lug. not all manufacturers make both, so this is something to consider before installing a panelboard. The 120/240 volt works for both applications.

A 240 volt load, such as a heater element, needs no neutral, but must have a n equipment ground. A straight 240 volt works simply. It will monitor the current flow in both hot legs. If the current flow differs between both by 5 milliamps or more, the difference is assumed to be leaking to ground, and the CB will trip.

A unit that needs 120 and 240 volt needs a neutral. For example, the heater needs 240 volts, no neutral, and the current in both hot legs will be the same, let's say 10 amps. If only the heater is running, there is no current in the neutral, only 10 amps on each hot leg.

Now add a 120 volt pump that draws 5 amps. It only connects to one hot leg, so it impose 5 amps on one hot leg and you can measure 5 amps on the neutral.

The one hot leg the pump is connect to sees the 10 amps of the heater plus the 5 amps for the pump, while the remaining hot leg stills only sees the 10 amps of the heater.

I believe it is this type of scenario that is concerning you.

They contain intricate and intuitive electronic measuring circuits that must monitor both hot legs and the neutral, and do the all the comparisons, by knowing that one hot leg, while has more load on one due to the pump, adds it, compares to the neutral, and as long as it sees the proper current , no tripping occurs.

Once the current flow differs 5 ma or more in any hot leg, and does not see the current flow in the return, whether the other hot leg or the neutral, it then assumes a leak to ground and trips.

This is why these breakers are so costly, in the range of $130.00 each.

Contacting the manufacturer is a great idea. I know, as I have done this many times before for various reasons, due to proprietary information and industrial secrets, you probably will not get a much better answer.

Plus, on your initial call ,I guarantee you will get some layperson in a call center reading a generic script for answers, and you will hang up not knowing any more than your when you first called.

Be patient and persistent to speak with a product engineer. He/she will do their best to explain the operation without giving away trade secrets.

I find that GE and Square D are fairly useless getting tech info. Siemens and Eaton ( Westinghouse and Cutler Hammer) are much better.

Sooooo, in the OP scenario where he is running 3 wires to the kettle heating element (2 hots and 1 ground) he does not need a neutral for the GFCI to work, again... scary thread we have going here.

Just install the GFCI and be done with it. Why take the chance and/or ask questions?

If your carboy is squeeky clean, do you absolutely positively really need Star San 100% of the time? Do you? But we use it anyway...because we don't want to take the chance.

I am straight up afraid for peoples lives here.

I think what people keep missing, even the electricians (scary) is that there is no neutral in a 240VAC circuit. You need two conductors to monitor the IN and OUT flow of current. In a 120VAC circuit this has to be done across the HOT and NEUTRAL, in a 240VAC circuit there is no neutral, but you still have two conductors... the HOT legs, this is where the GFCI will monitor it.

If you have a hybrid circuit that is feeding 240VAC and 120VAC stuff, you NEED the neutral obviously for the 120VAC stuff so that the GFCI can monitor the IN and OUT current, again.

This is why you can draw MORE off one leg than another (running 120VAC off one hot leg) because the GFCI will then read that extra current across the neutral and be fine with it. The GFCI needs to be wired to your neutral in your panel, but you do not need a neutral or a 4 prong/wire for the GFCI to work properly on a straight 240VAC circuit.

If you do not have a way for the GFCI to measure the current IN and OUT it will trip. How many guys here have wired their 240VAC kettles with 2 hots and a ground? Hands please... yup, okay about 100 of you. How many have had a GFCI trip when you turned the system on? Hands.... none? Must be monitoring the two hots just like the pro's say.

Call your electrician and tell him to refer you to someone with a working knowledge of electricity and components.

So, you're saying that in a three-wire setup (two hots and a ground) the CFGI measures the difference between the current in the two hot legs. Makes sense to me, but when I put this question squarely to my electrician, he said no, you need a neutral. He even called back to his office to ask another electrician, and they were in agreement. Your post mentions two different types of GFCI's, one for straight 240, and the other that can be used to split 120/240. Maybe he was only thinking about the latter?

Why do you keep saying this is a scary thread? I'm not suggesting that anyone do things one way or another, just trying to understand and do it right.

Yes, I could "just do it," but as a I said before, I want to really understand my rig and not buy myself a sense of false security if the GFCI doesn't actually help. My electrician's advice surprised me. I'm looking for answers, here.

It is scary because time and time again people are saying that electricians are saying no GFCI is needed, or that a neutral is needed for a GFCI to work properly... which is false.

I am scared that some newb will come in here, read this, and regardless of what is said, decide that it is OK to not use a GFCI because it is not needed, and electricians say that they wont work anyway without a neutral. Because that is what he wants to read, because it is $100 cheaper.

Do you want to know how many people here on HBT have them working just fine without a neutral? A lot. I have for 2 years, and if you run a search here for electric kettles, you will see a plethera of kettles, all running very happily on a GFCI. Your electrician claims that the NEUTRAL is needed so that the GFCI can monitor the current, so without a NEUTRAL it cannot... well then it would trip instantly, which they do not, because, again, there is no neutral in a straight 240VAC circuit, ever...

The only difference between the 240VAC and 120VAC GFCI is that one actually has the NEUTRAL LUG so that you CAN run a neutral if you are using 120VAC off the circuit as well. Like in a clothes dryer? You dont HAVE to have a neutral for it to work, but there is a lug there so that you can attach one and tap 120VAC too.

Ask your electrician where EXACTLY the neutral goes on a 240VAC pump? Where do you wire the neutral to ANYTHING that is 240VAC? The answer is, nowhere. So then we are to assume that you cannot GFCI protect ANYTHING that is 240VAC? See, the rabbit hole just gets deeper.

If they thought about it for a little bit, in these terms, they would realize that they are incorrect. You only have two conductors in that circuit, the GFCI is monitoring them both, it knows what is going on just fine.

In this case, Id say paying your electrician to tell you that you do not need a GFCI, is buying yourself a sense of false security.

My wife's cousin is an electrician. He does pretty much all new commercial install stuff. When I talked to him about installing my circuit, he wasn't aware that 240v gfci breakers were available with a neutral - I had initially wanted to split off some 120v for my pumps. I decided to go with a 3 wire 240v circuit (2 hots & ground) and run separate 120v for my pumps/PID/gas valve so that it would be easier to brew where 240v is unavailable.

One thing I know, for certain, is that GFCI can work, and save lives without a neutral on a double pole GFCI breaker.

Say you use a 240v breaker without gfci. The *only* thing that will cause that breaker to trip is if it exceeds it's rated output. 30A-50A? Maybe a wire comes loose somewhere in your rig but doesn't short ... and there's not path for current. Maybe things aren't grounded well. If you walk up to it and touch something that provides a path for current - that juice is going to flow through you. If it was a GFCI breaker, as soon as the breaker sees that there is power not accounted for it would trip. Probably give you a decent little shock. If it's non GFCI it won't trip until you reach the 30A-50A it needs to realize too much is flowing. It is scary to think of people running circuits they designed and built without the comfort of knowing if there is a breaker, which if it detects a ground fault, will shut off the power.

EXACTLY!!!

The ONLY reason that somen DP GFCIs come with a neutral lug is so that you have the OPTION of adding a 4th wire (neutral) to run 120VAC off that circuit. Clothes dryer??

The reason you have DP GFCIs that DO NOT HAVE a neutral lug is because a DP GFCI does NOT NEED the neutral to work.

These electricians should lose their licenses for not knowing something that a garage DIYer knows.

willynilly said:

Your electrician claims that the NEUTRAL is needed so that the GFCI can monitor the current, so without a NEUTRAL it cannot... well then it would trip instantly, which they do not, because, again, there is no neutral in a straight 240VAC circuit, ever....

Click to expand...

Well, THAT makes sense, anyway. Thanks for your responses. I've actually put in a fair amount of time looking through the posts on this site (and others) to see what others have done with their rigs, but I didn't come across anything that explained the apparent disparity between my electrician's advice and what seems to be common practice among my brewing bretheren. I hope your aren't discouraging posts like mine. If I didn't ask you guys the question, I'd probably have just gone ahead with what my electrician said, right?

Looks like 3-wire 240 isn't even code after 1996...

Translated: 3-wire 240 was invented to save copper, and is safe. As long as the Neutral never fails which would cause unsafe currents in the appliance. IOW it could electrify your brew rig if the neutral fails on your plug?
Coooolll

"Fixed appliances on three-wire circuits

In the USA, the cases of some ovens and clothes dryers were grounded through their neutral wires as a measure to conserve copper during the Second World War. This practice was removed from the NEC in the 1996 edition, but existing installations may still allow the case of such appliances to be connected to the neutral conductor for grounding. Note that the NEC may be amended by local regulations in each state and city. This practice arose from the three wire system used to supply both 120 volt and 240 volt loads. Because ovens and dryers have components that use both 120 and 240 volts there is often some current on the neutral wire. This differs from the protective grounding wire, which only carries current under fault conditions. Using the neutral conductor for grounding the equipment enclosure was considered safe since the devices were permanently wired to the supply and so the neutral was unlikely to be broken without also breaking both supply conductors. Also, the unbalanced current due to lamps and small motors in the appliance was small compared to the rating of the conductors and therefore unlikely to cause a large voltage drop in the neutral conductor."

SweetSounds said:

Looks like 3-wire 240 isn't even code after 1996...

Translated: 3-wire 240 was invented to save copper, and is safe. As long as the Neutral never fails which would cause unsafe currents in the appliance. IOW it could electrify your brew rig if the neutral fails on your plug?
Coooolll

"Fixed appliances on three-wire circuits

In the USA, the cases of some ovens and clothes dryers were grounded through their neutral wires as a measure to conserve copper during the Second World War. This practice was removed from the NEC in the 1996 edition, but existing installations may still allow the case of such appliances to be connected to the neutral conductor for grounding. Note that the NEC may be amended by local regulations in each state and city. This practice arose from the three wire system used to supply both 120 volt and 240 volt loads. Because ovens and dryers have components that use both 120 and 240 volts there is often some current on the neutral wire. This differs from the protective grounding wire, which only carries current under fault conditions. Using the neutral conductor for grounding the equipment enclosure was considered safe since the devices were permanently wired to the supply and so the neutral was unlikely to be broken without also breaking both supply conductors. Also, the unbalanced current due to lamps and small motors in the appliance was small compared to the rating of the conductors and therefore unlikely to cause a large voltage drop in the neutral conductor."

Click to expand...

You are right, which is why newer homes have 4 prong dryer outlets, not the old three prongs.

It should be noted, that we're all probably using "Neutral" and "Ground" interchangeably when we discuss 3-wire 240. That's probably a lot of where the confusion comes from.

In 3-wire 240v, there is no "Neutral" Just a Ground. Even though they go to the same place, they can have different potentials at your brew rig. (bad)
Hang a 110v load on one leg, tie it to the ground, and now it serves a neutral. (also making the current asymmetrical and tripping your GFI if you have one) ((Inducing current on your rig if you don't))

Has anyone else ever laid their arm on a jewelers/bakers/deli case frame and got a tingle on the arm??

CorgiBrew said:

Well, THAT makes sense, anyway. Thanks for your responses. I've actually put in a fair amount of time looking through the posts on this site (and others) to see what others have done with their rigs, but I didn't come across anything that explained the apparent disparity between my electrician's advice and what seems to be common practice among my brewing bretheren. I hope your aren't discouraging posts like mine. If I didn't ask you guys the question, I'd probably have just gone ahead with what my electrician said, right?

Click to expand...

Right, I mean, this stuff is deadly bro.

Your electrician was going to kill you... along with HANK9's electrician.

Then you get people chiming into the thread who are also just rattling off false information which makes the situation worse.

You cannot get the same protection as a GFCI without a GFCI
You do not NEED a neutral for a GFCI to work on a 240VAC circuit, because there is no neutral!

diatonic said:

I decided to go with a 3 wire 240v circuit (2 hots & ground) and run separate 120v for my pumps/PID/gas valve so that it would be easier to brew where 240v is unavailable.

Click to expand...

I'm doing the same thing (but maybe for different reasons): two control boxes, one 120v for the PID, pump, etc, the other 240v for the elements. The 120v box has always had GFCI protection. The whole reason my OP question came up was that, looking at setups like the Pol's, I see four wires going into the control box and three coming out (the neutral being used to split off the 120v). Just had to wonder if eliminating the neutral along the way made a difference to the GFCI. Not an issue for me, because my 240v is three wire all the way from the panel to the elements.

willynilly said:

Your electrician was going to kill you... along with HANK9's electrician.

Click to expand...

I definitely plan to call him and ask WTF.

CorgiBrew said:

I definitely plan to call him and ask WTF.

Click to expand...

Yeah, seriously, that is some BAD advice... REALLY BAD. Especially considering this is probably the most deadly thing you will deal with in a home, electricity and water....

willynilly said:

electricity and water....

Click to expand...

... cat

Great thread! Very good info!!!

SweetSounds said:

Has anyone else ever laid their arm on a jewelers/bakers/deli case frame and got a tingle on the arm??

Click to expand...

I get a tingle, alright, but it's in my wallet!

I firmly believe that it's threads like these that, as scary as they are, prove to be very valuable. There are thousands of lurkers out there, dreaming, scheming, planning...most posts read very informatively from different angles/opinions...not very many will wake you up about erroneous presumptions.

Call it constructive criticism or whatever you'd like...if it gets the point across then it is invaluable...especially with something as dangerous as this.

Okay, since I work at a huge company with plently of production lines, I asked one of our process, instrumentation & control engineers this question. He AFFIRMED what others on this thread have said: the GFCI WILL provide protection in a three-wire setup. Something to do with the neutral and the ground being bonded at the panel. According to the engineer, the neutral pigtail on the breaker should be attached to neutral bar. So, thanks to one and all.

All in all, a great lesson for me: question authority!

willynilly said:

There are two types of two pole GFI breakers, straight 240 volt, with no neutral lug, and 120/240 volt with a neutral lug. not all manufacturers make both, so this is something to consider before installing a panelboard. The 120/240 volt works for both applications.

Click to expand...

Sorry, I was assuming he was taking 120V to run pumps. When I reread his initial post it only mentions the heating elements.

I can see how a GFCI can protect you if you get across the hot line to a ground. There is also the situation where the ground is used for neutral at the load (for 120V), as well as being used for a chassis or kettle ground, and you lose the neutral connection to the load, thus potentially making the chassis or kettle "hot". Here, a GFCI would protect you because current flowing from the hot chassis or kettle through you to whatever other ground you contacted, would not return through the neutral line, thus tripping the GFCI. Now in a situation where the neutral is not used at the load, you still have the protection from getting across a hot to ground. The second situation above would not be likely as it would require both losing the ground connection plus a short from a hot line to the chassis or kettle. Still, a GFCI would protect you here, too, and it would seem to me that a GFCI would be a good thing to have.

I'm wondering about the statement that a neutral is not necessary on a GFCI if only 240 v is used at the load. I get the impression that the GFCI circuit inside the breaker uses the neutral, and will not work without it. Does anyone know for sure if this is the case? And if the GFCI won't work without the neutral on the pigtail, does it simply not stay on at all, or does it stay on and the GFCI function just doesn't work?

People using the spa disconnect boxes with the GFCI breaker for 240V only circuits (no wire to the neutral output of the breaker) - how are you connecting the neutral and ground? Do you tie the incoming ground wire both to the ground and neutral blocks, and also ground the kettle to this point? If you tie the incoming ground only to the neutral block, how do you ground the kettle? And if only to the ground block, does the GFCI breaker work without a neutral connection to the pigtail?

Again, if you are running a 240VAC circuit, there is no neutral to attach. So, the GFCI will work without a neutral being run. Yes, if you have a DP GFCI breaker that has a neutral pigtail, that should go to your neutral bar in the breaker box. Whether you have a neutral on the neutral lug on the GFCI is really irrelevant since if you are running a 240VAC circuit only, there are no neutrals in your system. 240VAC pumps etc. do not have a neutral, so there is no way you can incorporate a neutral.

GFCI only monitors IN and OUT current to make sure it is equal, to make sure you dont have a ground fault somewhere. This will only require the 2 hots in the case of a 240VAC circuit. I dont know how many different ways I can say it, but a GFCI on a 240VAC only circuit does NOT need a neutral.

Some DP GFCIs have a neutral pigtail and a neutral lug, this is in case you are running a 4 wire circuit with a neutral incorporated so that you can tap 120VAC off that circuit. In the OP's system he ONLY has 240VAC being run, so the GFCI is monitoring only the 2 hots, which is what it is made to do. Some DP GFCI's do NOT have a neutral pigtail or lug... these do not monitor any neutrals, they are for straight up 240VAC applications and they ALSO monitor the 2 hots.

Either DP breaker is perfectly capable of monitoring the 2 hots alone to detect a ground fault, there is no neutral needed. Period.

If it didnt work, the GFCI would not work at all. If the GFCI isnt getting an IN and OUT reading that it can compare, it will trip. The simple fact that so many DP GFCIs out there are operating 240VAC circuits with no neutral, proves what we already know... you do not need a neutral. Again, no 240VAC circuit utilizes a neutral to begin with.

Also, when talking about spa panels and the like... grounds and neutrals are tied, they are common, in the breaker panel. I presume this is the same in a spa panel.

willynilly said:

Again, if you are running a 240VAC circuit, there is no neutral to attach. So, the GFCI will work without a neutral being run. Yes, if you have a DP GFCI breaker that has a neutral pigtail, that should go to your neutral bar in the breaker box. Whether you have a neutral on the neutral lug on the GFCI is really irrelevant since if you are running a 240VAC circuit only, there are no neutrals in your system. 240VAC pumps etc. do not have a neutral, so there is no way you can incorporate a neutral.

GFCI only monitors IN and OUT current to make sure it is equal, to make sure you dont have a ground fault somewhere. This will only require the 2 hots in the case of a 240VAC circuit. I dont know how many different ways I can say it, but a GFCI on a 240VAC only circuit does NOT need a neutral.

Some DP GFCIs have a neutral pigtail and a neutral lug, this is in case you are running a 4 wire circuit with a neutral incorporated so that you can tap 120VAC off that circuit. In the OP's system he ONLY has 240VAC being run, so the GFCI is monitoring only the 2 hots, which is what it is made to do. Some DP GFCI's do NOT have a neutral pigtail or lug... these do not monitor any neutrals, they are for straight up 240VAC applications and they ALSO monitor the 2 hots.

Either DP breaker is perfectly capable of monitoring the 2 hots alone to detect a ground fault, there is no neutral needed. Period.

If it didnt work, the GFCI would not work at all. If the GFCI isnt getting an IN and OUT reading that it can compare, it will trip. The simple fact that so many DP GFCIs out there are operating 240VAC circuits with no neutral, proves what we already know... you do not need a neutral. Again, no 240VAC circuit utilizes a neutral to begin with.

Also, when talking about spa panels and the like... grounds and neutrals are tied, they are common, in the breaker panel. I presume this is the same in a spa panel.

Click to expand...

We seem to have a communication problem here. I'm not sure I understand if you are saying that the breaker pigtail doesn't have to be connected at all? I understand that you don't need a neutral on a 240 v only system - you have only 2 hots and a ground coming in and going out, but what I'm trying to understand is whether or not the neutral pigtail on the breaker needs to be tied to the incoming ground, and that would seem to hinge on whether or not the circuitry internal to the breaker depends on having that pigtail grounded. From what I've read, I got the impression that this ground was used as part of the breaker internal circuit to induce a 120 Hz signal onto the lines through the breaker toirodal coil to detect grounded neutrals and "hotted hots". If this is the case, then the pigtail has to be tied to ground, which would serve the same purpose as a neutral on a 4-wire system for this internal breaker circuit only. If the breaker pigtail is tied to the neutral block in the spa box, then it would seem necessary to tie the incoming ground to the neutral block as well as the ground block. Alternatively, the incoming ground could go only to the ground block and the pigtail also to the ground block - it really doesn't make any difference.

Okay,
I've worked with a lot of electricians. You'd be surprised how many only know how to WORK WITH electricity and know what the codes are, yet they don't understand the principles at hand and exactly why they work.

Ground fault circuit interrupters will trip when the sum of all current entering and leaving the gfci, through leg a, leg b, or the neutral does not balance within a few milliamps it will trip. A ground fault occurs when current has found an alternate path to ground.

Reminds me of a recent conversation I've had with some one.
Say you have a 4 wire service, and you have 2 heating elements of equal value. One element is attached to Leg1 and Neutral, the other to Leg2 and Neutral. And lets say each element has a value of 1200W, so they each draw 10A a piece from their respective Legs.
Here's the question, if both elements are on where is all the current? Common sense would say, 10A on Leg1, 10A on Leg2, and 20A on the Neutral right?

Wrong. If you measure the current running through the Neutral you would see 0 Amps. Current is flowing 10A from Leg1 through Leg2 via both elements. This is because the load is balanced. When the load is out of balance, you will see the difference in current on the Neutral. So if you turn off one element you will see 10A flowing through the Neutral.

Since either leg is at opposing ends of the wave form, if L1=100V then L2=-100V, you can measure the sum of the current flowing through each leg since they will be opposing as well. Then the gfci adds the current on the Neutral. If the Sum of L1amps+L2amps+Namps will ideally equal 0amps, if it is greater than +/- 5(ish) mA something is leaking.

As you can see the Neutral does not need to be present for a gfci to function as long as the load across the 240V is balanced.

Thats the nuts and bolts of a 240V gfci and you can take it to the bank.

If you only have a 3 wire service for 240V then I recommend you do not split the legs into 110V, if it is a three wire system the Ground/Neutral should go straight to the ground/neutral bar in the main panel. Consider it ground. I don't like to mix services but this is one of those situations where I would rather have to pull a separate 110V source with dedicated Neutral than to mix ground and neutral.

This topic always confuses me. My electrician nephew says that there is no difference between neutral and ground in a 3 wire 240 volt circuit. The circuit needs a third wire. (Actually - he calls it neutral.) He also says that a GFCI is like wearing a leaky condom. Maybe you're protected - maybe not. I don't know! I'm not trying to stir anything up - I just don't know. Reading the website about GFCI's posted earlier, I did notice that it seemed to say not to use a GFCI with "major appliances" - so, does a 5500 watt element qualify as "major"?

jim4065 said:

This topic always confuses me. My electrician nephew says that ... a GFCI is like wearing a leaky condom. Maybe you're protected - maybe not. I don't know!

Click to expand...

That is the only thing your nephew has right. Though I would give them a little more credit than that. It's not something that should be used to permit dangerous or shoddy practices. But if by some freak accident you get hooked up, you should give yourself every chance possible.

No offense but, you're nephew ought to go pay Tom Henry a visit.

as far as large appliances go, Spa's are required to have them and on average they use a 50A service. See what I'm getting at here?

The neutral pigtail should be tied to the neutral/ground common in the breaker panel. The incoming GROUND from the brewing system should be tied to the neutral/ground common as well. Why wouldn't you? If you have it, use it...