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Why are the GFCI breakers nuisance tripping in your 100 amp sub panel- is it because neutral bonded to ground?
Wiki User
∙ 11y ago
It may be the GFCI breaker is defective. Make sure it is wired correctly. Neutral to neutral bar and ground to ground bar.
Wiki User
∙ 11y ago
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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.
Do gcfi breakers operate with only hot and neutral ?
yes. A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit.
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 does the 59n relay keep tripping the breaker?
The 59 relay is an overvoltage relay. The 59N relay is an overvoltage relay for the neutral circuit. Check neutral and make sure the system is properly balanced.
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.
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.
What is meant by tp and tpn circuit breakers?
The difference of TP and TPN in circuit breakers is the ability of the switch to hold a neutral position. With TPN, a neutral switch position is not possible. With TP, the breaker can be held in a neutral position.
Will a GFI outlet keep tripping because it's line is wired to a fuse box panel where the neutral and ground are together?
No, that alone would not cause a GFCI to trip because that is the proper way to wire a panel.
Do gcfi breakers operate with only hot and neutral ?
yes. A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit.
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.
How do you split up a 240 volt outlet for 110 power?
A 220 outlet will have one neutral (white) and two hots (black and red normally) just use the neutral and just one of the two hot wires. Careful where you do this because normal 110 breakers are 15 or 20 amp and normally 220 breakers tend to be either 30 amp for a dryer or 50 amp for a stove.
Why does the 59n relay keep tripping the breaker?
The 59 relay is an overvoltage relay. The 59N relay is an overvoltage relay for the neutral circuit. Check neutral and make sure the system is properly balanced.
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.
Why would your pool circuit breaker go off?
Probably because you are either drawing too much current or you have a ground fault. If your ground fault breaker is tripping, or if you have a ground fault receptacle is tripping then you have too much circulating current through your neutral. There are many factors to consider there. Provide more information about what is on the pool's circuit and we can explore the options.
You have problem of simultaneous tripping with other small power circuits but not instant?
Answer for countries in Europe and other world areas running a 50 Hz power supply service. Tripping of what - RCD would probably point towards an earth/neutral fault Tripping of MCB would point to a small overload or a circuit with a thermostatically controlled device such as a fridge.
Why neutral CT are used for protection?
Neutral CTs are used to measure neutral current, which is indicitive of a problem on the power system that protective equipment should interrupt. A similar question would be "why use phase CTs...". Because they can be used to tell the protective device that something is abnormal, and action should be taken. Neutral CTs can be used for several different things - overcurrent tripping, polarizing, and zone limiting (as in restricted earth fault protection for transformer differentials).
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.
