Heating Elements and GFCI

[illin8]

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.

 

[CorgiBrew]

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!

 

[Marsdude]

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.

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

 

[DeafSmith]

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?

 

[willynilly]

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.

 

[DeafSmith]

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.

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.

 

[CodeRage]

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.

 

[jim4065]

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"?

 

[CodeRage]

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!

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?

 

[willynilly]

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...

 

[CodeRage]

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...

I guess you are asking me.

Though the ground and neutral are bonded in the same spot on the main breaker they SHOULD not be considered the same thing. The electrical primer in my sig explains why in detail.

 

[Marsdude]

What willynilly is stating is correct. A 240 AC circuit does not need a neutral. The reason for that is because the current is alternating on each conductor allowing one flow electrons to the heating element (in this example) and the other allowing the electrons to flow to ground thereby creating the circuit.

As willynilly stated several posts ago there are two different types of GFI breakers for a 240 AC circuit. One does not need a neutral pigtail like is seen in a 120 GFI breaker because it is monitoring the current flow between the two conductors. If you don't split out 120V from your 240V circuit you are safe when you use one of these breakers.

If you do split out 120V from your 240V circuit, to run a pump for an example, then you really should have four wires from your service panel consisting of the two "hot" conductors, a neutral, and a ground wire. In this case you need the 240V GFI breaker that does have the neutral pigtail.

Although they terminate at the same buss in the service panel a neutral and a ground are not the same thing. A neutral carries a current - a ground wire should not. A neutral completes the circuit to ground, a ground wire is a safety measure in case a short occurs in the circuit.

 

[the_Roqk]

I guess you are asking me.

Though the ground and neutral are bonded in the same spot on the main breaker they SHOULD not be considered the same thing. The electrical primer in my sig explains why in detail.

On my main 200 amp panel (home) the neutral and ground are NOT bonded. But I did notice that the neutral is not bonded to the panel itself but that the ground is. Also the ground has a seperate bond to the metal grounding rod that is outside. Is this to code? Or should they both be bonded together?

Hopefully this isn't too off topic

 

[CodeRage]

They may have bonded the Neutral tap on the transformer directly to the ground rod and then run the Neutral from the tap to the panel and earth ground from the rod to the panel. The only way to be sure is to follow the ground wire from the rod, it should end up meeting the Neutral some where. You could measure the voltage from the neutral bus to the ground bus and measure close to 0V. If you're feeling brave after that point you could set your meter to continuity testing and try to ring out neutral to ground. If it buzzes then they are bonded some where. If it doesnt buzz they are either open or you burnt the fuse in your meter .

 

[willynilly]

I guess you are asking me.

Though the ground and neutral are bonded in the same spot on the main breaker they SHOULD not be considered the same thing. The electrical primer in my sig explains why in detail.

Nope, I wasnt asking anyone.

Because I KNOW that they should not be considered the same. I was answering a question that was posted earlier.

 

[P-J]

There is somethnig missing in the_Roqk's description. Neutral and ground have to be bonded at the structure. It is possible that the meter pan is also a CB panel on the outside of the house. The common bond could be there and then neutral and ground delivered to the inside panel through seperate conductors.

 

[CodeRage]

Nope, I wasnt asking anyone.

Because I KNOW that they should not be considered the same. I was answering a question that was posted earlier.

Sorry about that, misunderstanding on my part.

 

[Henrythe9th]

could someone post a link to one of these 110v/220v dd throw GFIC breakers..
I still cant decide to go with both a 110 circuit and a 220 stand alone..
what about using a hot tub breaker would that be to many amps.. 50 a for a 20 amp circuit
Thanks

 

[CorgiBrew]

Spoke to the chief electrician at the company that did the installation in the OP. He agreed with essentially everything that was said here. I feel very fortunate to be part of this community. Thanks.

 

[willynilly]

Spoke to the chief electrician at the company that did the installation in the OP. He agreed with essentially everything that was said here. I feel very fortunate to be part of this community. Thanks.

We saved your life

 

[CorgiBrew]

We saved your life

I'll drink to that!

 

[CorgiBrew]

could someone post a link to one of these 110v/220v dd throw GFIC breakers..
I still cant decide to go with both a 110 circuit and a 220 stand alone..
what about using a hot tub breaker would that be to many amps.. 50 a for a 20 amp circuit
Thanks

Check out CodeRage's primer on electricity. A 50 amp breaker on a 20 amp circuit is a definite no-no. There are a lot of 50 amp GFCI breakers out there because people use them for hot tubs. I'm looking for a 30 amp GFCI right now myself. Not as easy to find locally. If anyone knows a source at a reasonable price let me know.

 

[the_Roqk]

There is somethnig missing in the_Roqk's description. Neutral and ground have to be bonded at the structure. It is possible that the meter pan is also a CB panel on the outside of the house. The common bond could be there and then neutral and ground delivered to the inside panel through seperate conductors.

You are right that the meter is bonded to a ground (there is a bare copper wire coming out of the meter box to a grounding rod). But there is no way of knowing if the neutral is bonded to the ground at the meter. Unless the Electric company does this before service connection. I suppose I can ask my electric provider if that is standard.

 

[Catt22]

We saved your life

The shocking reality is that you may actually save many lives with this information. Good job!

 

[Reno_Raines]

I bought a 30 amp dual pole GFCI breaker today for my hot tub and it cost $137. It was Eaton Cutler-Hammer brand. I have seen them on ebay for a little less but I wanted it today. Thirty amp is rare, Lowes only had a 50 amp and a 100 amp.

 

[willynilly]

I bought a 30 amp dual pole GFCI breaker today for my hot tub and it cost $137. It was Eaton Cutler-Hammer brand. I have seen them on ebay for a little less but I wanted it today. Thirty amp is rare, Lowes only had a 50 amp and a 100 amp.

You can get an Eaton Cutler Hammer 50A DP GFCI at HD for $99 The 30A ones were running about $85 there.

 

[jim4065]

I bought a 30 amp QO Square D GFCI on ebay and it's not right. Mine uses a "snap-in" breaker where this one has two brass bolts at the top to pick up power. That'll teach me to "save". Went to an electrical supply house today - $100 for the "right" breaker. He has a bunch of 20 amp GFCI's on sale, but I don't figure they'll work with a 5500 watt element.

 

[dobeluvr]

gfci-- do we need one-- no it will work just fine without one, believe it or not there was a time before the gfci and afci, Common household equipment still not requiring gfci include washing machines (have you ever touched one while it is running?), sump pumps and electric hot water heaters (if you have one you dont think twice about taking baths, doing dishes), refrigerators (if on a dedicated circuit) even if it is within 6 ft of a sink, and dont forget coffee pots--a few still have metal parts

HOWEVER

and it all comes down to a few questions?

How safe do you want to be?, and how much do you value your life? Safety equipment, and that is what a gfci is, is something we dont ever want to "need", but if you have it AND if you use it, it just may save your life.

 

[passedpawn]

I bought a 30 amp QO Square D GFCI on ebay and it's not right. Mine uses a "snap-in" breaker where this one has two brass bolts at the top to pick up power. That'll teach me to "save". Went to an electrical supply house today - $100 for the "right" breaker. He has a bunch of 20 amp GFCI's on sale, but I don't figure they'll work with a 5500 watt element.

That stinks dude. I bought a SquareD QO 2-pole GFI on ebay for $50 and it has performed perfectly. The part number (I'd guess you know it already, but...) is QO230GFI.

I just looked... here is a listing for them, and they are snap-ins. Same guy I bought from 5 months ago!

http://cgi.ebay.com/qo-GFI-2-pole-Circuit-Breaker-qo230gfi-SQUARE-D-gfci_W0QQitemZ300350557447QQcmdZViewItemQQptZBI_Circuit_Breakers_Transformers?hash=item45ee49cd07

 

[olympionex]

Home Depot has a 50A 240V GFCI in a nice outdoor electrical box for $49.00. I believe this GFCI has neutral protection for 120v loads as it does have a neutral pigtail. I will test the functionality soon to make sure that a ground fault trips the 120. This is a pretty unbelievable deal compared to the breakers. Home depot also sells the Siemens and another brand GFCI breaker for $85 which is still cheaper than many places online.

The $49 is called a Spa Disconnect Panel
Model # UG412RMW250P


There is a $69 version with a 60A GFCI as well.

I've got 5.5KW heating 15 gals of water right now. 240 is going to be great! I'm glad its now possibly to do it safely and cheaply.