Properly wired 220v GFI Breaker?

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tadavidson

tadavidson

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Georgia
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Electrical Contractor
I purchased a double pole,220v, GFI breaker. When I looked at the installation sheet it showed 3 lugs for use. 2 for line and 1 for neutral. Then the factory white wire (curly)to go to the neutral bar. I dont understand. There isn't a neutral on 220v circuits. This is the situation: 5 conductors are pulled to a J box. 3 lines, one common (neutral) and one equipment grounding conductor. 1 line and the common (neutral) feed 2 GFCI recptacles. The other 2 lines and an equipment grounding conductor go to the 20a, 220v outlet. In the J box the grounding conductors from the three outlets tie together and go back to the ground bar.. CAN you explain why they ask for the "neutral" to connect to the lug on the breaker. Thanks in advance for your interpretation.
Terry Davidson
 
Re: Properly wired 220v GFI Breaker?

Here's the nickel tour: A 2-pole GFCI breaker is wired differently internally than a single-pole GFCI breaker. The 2-pole is designed so that all 3 wires (the two ungrounded-conductors and the one grounded-conductor) pass through the same pickup core for current sensing. The white pigtail to the neutral buss gives a point of reference to ground.
 
Re: Properly wired 220v GFI Breaker?

I was taught (maybe incorrectly, it has been several years) the neutral carries the unbalance of a three wire circuit. There isn't a "neutral" in a 220v circuit.. If the manufacturer means the grounding conductor it should read grounding conductor.
 
Re: Properly wired 220v GFI Breaker?

Your breaker can be used as a GFCI for a 240 circuit like you want to, or it can be used for a Multiwire branch circuit that will need the Neutral connection

A GFCI needs no 'reference to ground' it will need a connection to the neutral bar when a neutral is part of the circuit it is protecting.
 
Re: Properly wired 220v GFI Breaker?

Just because a circuit is 220, does not mean there is no neutral. Many 220 devices have components that are 110. These components need a neutral. Examples include dryers and ranges, which have lights, clocks, timers, etc.
 
Re: Properly wired 220v GFI Breaker?

The application is a 2 1/2 hp pump for a goldfish pond. It is the sole load on the outlet. There are no 110/120 loads... It is my understanding that the GFCI recpt./breakers "read" a loss on the neutral (grounded)conductor as compared to the ungrounded conductor and when this level reaches approx. 300ma it opens the circuit. The reason for the connection to the neutral (on a sub panel) or the ground bar on a main panel is to give 120v loads a ground for the circuit to operate. This outlet is wired with non-metalic sheathed cable the equipment grounding conductor is shared in the first J box with two other outlets. I will accept that if I connect the grounding conductor to the lug provided on the breaker that it may "read" on the grounding conductor and open the circuit preventing a serious condition. Beat me up on this one guys if I need it. I just cant get it. AS a side bar, on circuits (where the frames are metal) that are rated 220v but also have 120 loads they require a four wire circuit don't they?
 
Re: Properly wired 220v GFI Breaker?

tadavidson
In the application you are saying that the only load is 240vac. and there will be no 120vac loads then all you do with that type of breaker is do not connect any wire to the neutral connection on the breaker as if the ground wire is connected to that connection then it will pass the available circuit current through the ground wire too and this would defeat what the GFCI is design to do. The grounding (bare) conductor is to be connected to the grounding /neutral bar ONLY! And a GFCI does not allow 300ma. to ground before it trips as a class A device only allows 5ma. of current to ground before it trips and a fountain requires a class A type device better known as a GFCI. A GFEP is rated at 30ma. and a AFCI has a 30ma GFP or a 5ma GFCI or both depending on which one you get. Now you have the function close, It is the deferential of the current between the hot and the neutral or both hots or both hots and the neutral that trip the GFCI and not any reference to ground. A GFCI, AFCI, or a GFEP does not need any grounding conductor to reference. But in the case of a 2-pole breaker it does require a little 120 volt current for it's own electronics to work and that is the reason the neutral tail from the breaker has to be connected to the neutral/grounding bar. Just connect the two circuit hots to the breaker and connect the neutral tail from breaker to the neutral bar and you will be set to go.
I hook up many hot tubs and we get both 3-wire and 4-wire versions we use to order the 2-pole breakers that didn't have a neutral connection for the 3-wire hot tubs, but later found out that the ones that have a neutral connection will still work just leaving the neutral terminal empty. so now we stock only one kind.
Do a search on this site and you will find in detail all about GFCI's
 
Re: Properly wired 220v GFI Breaker?

A two pole breaker is only one 120 volt breaker with all current carrying conductors run through the toriod transformer of the single pole side.

Net current, as a result of a ground fault, will be detected and initiate a trip.

The neutral to the bus is to provide 120 volts for operation of the solenoid trip.

[ May 10, 2004, 03:24 AM: Message edited by: bennie ]
 
Re: Properly wired 220v GFI Breaker?

Thanks to all, Special thanks to hurk27 for the lesson. I wonder, why did I look at the information sheet supplied?
 
Re: Properly wired 220v GFI Breaker?

My bad. Posting error. No grounding reference needed. Sum of L1+L2 current must equal zero. If beyond threshold of GFCI sensing coil, GFCI will trip.
 
Re: Properly wired 220v GFI Breaker?

I agree that the breakers, and their instructions, need some clarifying. I recently installed a premium brand which has the neutral connection marked as "line." Go figure.
If you have a neutral (four wire), use it. If you don't, try it without moving the ground wire from the ground bus. If it trips, connect the ground to the gfi- something in the appliance is using 110.
 
Re: Properly wired 220v GFI Breaker?

Reno:
If it trips, connect the ground to the gfi- something in the appliance is using 110.
Click to expand...
If you connect the grounding conductor to the neutral connection on a two-pole or a single pole breaker you will put anyone that uses the equipment that these breakers supply at a risk of electrocution! This is wrong information to be giving out. If the neutral terminal on a GFCI breaker will allow the full current of the breaker to be drawn from it what do you think it will do with a ground connected to it? the same thing. this is why grounding conductors must always be only connected to the grounding bar. If a neutral is required for the equipment then only a four-wire connection can be used period!
Sorry for being a little harsh but instruction's like this can get people DEAD and should never be suggested.
 
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