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Can 12 2 w gnd wire be used for two different 20 amp circuits safely meaning I would have two separate circuits on two separate 20 amp breakers There would only be 1 white wire returning?
Wiki User
∙ 13y ago
Yes, you can do this, but there are a few rules to follow. The white wire(neutral) should be solidly made at all device boxes in other words do not use the receptacle terminals, make all the joints solid and pigtail to the receptacle. The breakers need to be adjacent to each other in the panel, side by side on opposite buss bars. If you put them on the same buss you will overload the neutral. Use a handle tie on the breakers.
I am sorry. It was the wrong question. The question really should have been: Can you wire two separate 20 amp circuits using one single romex 12-3 w/ground. Each circuit would have it's own 20 amp breaker. The Red wire would be landed on one breaker. The Black wire would be landed on another breaker. Only one #12 white wire would be available for neutral. My theory is: If you were to load both circuits to say 19 amps each, you would have 38 amps being used. The problem lies in the single white neutral's ability to handle 38 amps on it's own. Wouldn't this be a problem? Would this configuration pass in spection? You can do this with 12/3, you still have to make up your neutrals at device boxes. the neutral would not have to handle 38 amps as long as you use opposite 110volt buss. the current on the neutral if both breakers were drawing 16 amps each would be "0". The neutral only has to carry the imbalance of the two circuits. If one breaker draws 16 amps and the other 8 the current on the neutral would be 8 amps. Breakers have to be on opposite buss! for this to work. Yes, it should pass inspection.
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∙ 13y ago
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Do you have to pin breakers together when sharing the neutral on branch circuits?
Pinning breakers is becoming a thing of the past. This is due to the manufacturing of two pole breakers with one common trip reset handle. The electrical code states that on a 240 volt breaker if one leg trips the other leg must be disconnected from the supply also. This is a safety factor so that if they weren't tied together and one leg tripped the other half of the breaker would remain "hot". Any one working on that circuit in the tripped position could get a nasty shock from the un-tripped leg. Pinning the breakers on 240 volts was done because it was convenient to use single pole breakers in the distribution panel. To abide by the code the two single pole breakers were common tied together. When the branch circuits share a neutral to a common box they have to be common tied for the same reason above. This type of circuit is found on kitchen counter receptacles. Two separate circuits that share a neutral and go to separate junction boxes do not need the breakers tied.
What is an electric shared neutral?
An electric shared neutral is the white or negative wire that is shared between two electrical circuits on a basic single phase system. Most electrical devices use 120 volts and require a "hot" wire and a neutral wire to operate. Some larger devices use 240 volts and require two "hot" wires to operate. Two circuit breakers in an electrical panel can share one neutral wire as long as the breakers are not on the same "leg" of power. When looking at an electrical panel there are usually two "legs" of power feeding all the breakers, each leg has 120 Volts to ground, if the "legs" are combined you will have 240 Volts. A neutral wire can be shared by two circuits as long as the breakers are on separate "legs". If someone needed to add two circuits in their home, the could run what is called a 3-wire romex, It has a black wire, a red wire, a white wire and a ground wire. The white wire is the neutral for both the black and red 120 volt circuits, and the breakers for the new circuits would need to be on separate "legs" in the panel.
Any problems with shared neutral for for 4 15 amp breakers each on dedicated circuits?
Yes. If it a residential home then you can only have two breakers per neutral and they need to be on opposite legs of your panel. If it is a commercial 3phase panel then you can only put 3 breakers on a shared neutral. Here's why. In your panel assuming its residential you have two power wires and one neutral and these power wires are called legs. If you attach two breakers on the same leg that is across from each other on opposite sides of the panel or skipping a space between breakers on the same side at 15A apiece you return on the neutral will not be balanced and you will have the possibility of 30A coming back to your panel on the neutral which will fry a 14 Awg or even 12 Awg for that matter and cause a fire. Now if the breakers are in tandem that is they have the breaker tie that connects two breakers together they will be on separate legs and then only will your breakers/circuits be balanced and it will be safe to share a neutral on. If two tandem breakers are connected to a single neutral and they are all 15A breakers your return would be 30A again because although your tandem breakers are balanced now you have two tandem breakers returning a potential 15A per two breakers and that adds up to 30A. The next problem you have is when you share a neutral as per the National Electric Code if one breaker trips the other breaker also sharing that neutral must trip so that when the power is off any current that could possibly return through the neutral wire will be cut off. So now this creates another problem with 4 breakers sharing the same neutral is now there is no way to get all four to trip at the same time if there was a ground fault (a short) or an overload. and someone could get nailed by any current coming back on the shared neutral. All the same applies for 3phase except there are 3 power wires and you can use 3 breakers with a 3 breaker tie instead of just two. You either need to run one neutral per tandem breaker or four neutrals for four circuits/breakers. Tandem breakers controlling two separate circuits are a pain because when one breaker trips they trip the other circuit also. Tandems are mostly used for two circuits going to the same appliance so that no power on either leg reaches the appliance when it needs to be off.
When a home circuit breaker opens the lights in some rooms go off but the lights in some rooms stay on. Explain why.?
The circuit breakers in a panelboard feed separate circuits. The lights that stay on are on a different circuit than the ones that go off. To fine the circuit that feeds the lights that stay on, go to the panelboard and turn off the breakers one by one until the lights go out. This is the circuit that feeds that circuit of lights. Remember that lights and receptacles can be on the same circuit together.
How do you change one breaker on a 3 wire that feeds two regular circuit breakers to a single arc fault circuit breaker - or do you have to change both breakers to arc fault so each has a neutral?
You can't change the one breaker, but you can't use two separate arc fault breakers unless you separate the neutrals. However double pole arc fault breakers are made for this purpose and the common neutral would be O.K.
Why are ranges on separate breakers from refrigerators?
Because of the different ranges of amperages of each device.
Do you have to pin breakers together when sharing the neutral on branch circuits?
Pinning breakers is becoming a thing of the past. This is due to the manufacturing of two pole breakers with one common trip reset handle. The electrical code states that on a 240 volt breaker if one leg trips the other leg must be disconnected from the supply also. This is a safety factor so that if they weren't tied together and one leg tripped the other half of the breaker would remain "hot". Any one working on that circuit in the tripped position could get a nasty shock from the un-tripped leg. Pinning the breakers on 240 volts was done because it was convenient to use single pole breakers in the distribution panel. To abide by the code the two single pole breakers were common tied together. When the branch circuits share a neutral to a common box they have to be common tied for the same reason above. This type of circuit is found on kitchen counter receptacles. Two separate circuits that share a neutral and go to separate junction boxes do not need the breakers tied.
What is an electric shared neutral?
An electric shared neutral is the white or negative wire that is shared between two electrical circuits on a basic single phase system. Most electrical devices use 120 volts and require a "hot" wire and a neutral wire to operate. Some larger devices use 240 volts and require two "hot" wires to operate. Two circuit breakers in an electrical panel can share one neutral wire as long as the breakers are not on the same "leg" of power. When looking at an electrical panel there are usually two "legs" of power feeding all the breakers, each leg has 120 Volts to ground, if the "legs" are combined you will have 240 Volts. A neutral wire can be shared by two circuits as long as the breakers are on separate "legs". If someone needed to add two circuits in their home, the could run what is called a 3-wire romex, It has a black wire, a red wire, a white wire and a ground wire. The white wire is the neutral for both the black and red 120 volt circuits, and the breakers for the new circuits would need to be on separate "legs" in the panel.
Any problems with shared neutral for for 4 15 amp breakers each on dedicated circuits?
Yes. If it a residential home then you can only have two breakers per neutral and they need to be on opposite legs of your panel. If it is a commercial 3phase panel then you can only put 3 breakers on a shared neutral. Here's why. In your panel assuming its residential you have two power wires and one neutral and these power wires are called legs. If you attach two breakers on the same leg that is across from each other on opposite sides of the panel or skipping a space between breakers on the same side at 15A apiece you return on the neutral will not be balanced and you will have the possibility of 30A coming back to your panel on the neutral which will fry a 14 Awg or even 12 Awg for that matter and cause a fire. Now if the breakers are in tandem that is they have the breaker tie that connects two breakers together they will be on separate legs and then only will your breakers/circuits be balanced and it will be safe to share a neutral on. If two tandem breakers are connected to a single neutral and they are all 15A breakers your return would be 30A again because although your tandem breakers are balanced now you have two tandem breakers returning a potential 15A per two breakers and that adds up to 30A. The next problem you have is when you share a neutral as per the National Electric Code if one breaker trips the other breaker also sharing that neutral must trip so that when the power is off any current that could possibly return through the neutral wire will be cut off. So now this creates another problem with 4 breakers sharing the same neutral is now there is no way to get all four to trip at the same time if there was a ground fault (a short) or an overload. and someone could get nailed by any current coming back on the shared neutral. All the same applies for 3phase except there are 3 power wires and you can use 3 breakers with a 3 breaker tie instead of just two. You either need to run one neutral per tandem breaker or four neutrals for four circuits/breakers. Tandem breakers controlling two separate circuits are a pain because when one breaker trips they trip the other circuit also. Tandems are mostly used for two circuits going to the same appliance so that no power on either leg reaches the appliance when it needs to be off.
Can a garbage disposal be on when a dishwasher is on?
Yes, they should be on separate breakers.
When a home circuit breaker opens the lights in some rooms go off but the lights in some rooms stay on. Explain why.?
The circuit breakers in a panelboard feed separate circuits. The lights that stay on are on a different circuit than the ones that go off. To fine the circuit that feeds the lights that stay on, go to the panelboard and turn off the breakers one by one until the lights go out. This is the circuit that feeds that circuit of lights. Remember that lights and receptacles can be on the same circuit together.
How do you wire two lighting circuits through a time clock?
If you mean two separate circuits from different breakers, you will need a 2-pole time clock. The circuits will need to be kept completely separate, including neutrals. Remember that a time clock is just a switch operated by a timer and you only switch the hot wires. The clock will be operated by one of the circuits. For this you will need the neutral of that circuit connected to the neutral contact of the clock. This is all rather simple if you can follow the wiring diagram provided with the clock. I doubt you can find a 2-pole clock at the local hardware or home improvement store. You may have to go to an electrical supplier. I say this is simple and for an electrician it is. If you get the clock you need and it doesn't make sense to you in a minute or two you should not attempt to do this yourself. Crossing the hot wires or connecting the wrong neutrals to each other can create very unsafe conditions.
How do you change one breaker on a 3 wire that feeds two regular circuit breakers to a single arc fault circuit breaker - or do you have to change both breakers to arc fault so each has a neutral?
You can't change the one breaker, but you can't use two separate arc fault breakers unless you separate the neutrals. However double pole arc fault breakers are made for this purpose and the common neutral would be O.K.
Why don't my brake lights work but my tail lights do?
they are two separate circuits
Why brake light and turn signal don't work but hazards works?
They have separate circuits with separate fuses and separate flasher relays depending on what year the truck is.
What type of circuits have load on separate branches of a loop?
parallel circuitsThey could be called twin-loop circuits but it isn't a term in common use.
How many circuits required for 4 unit condo separate garages?
My questions also has 4 answers is it 1, 2, 3, or 4, circuits.
