In a perfectly balanced 3 phase system, the neutral current will be zero. This is because the neutral carries the vector sum the currents in the other 3 phases which when balanced sum to zero. In an unbalanced system, the neutral carries the current imbalance. Simply so, how much current does the neutral wire carry?
The purpose of the neutral wire is to carry back the unbalance of the load. So in a normal (US) house of 120/240 volts single phase, if one of your hot wires is carrying 30 amps and the other is carrying 23 amps, then the neutral will have to be able to carry 7 amps to keep the system balanced.
Furthermore, how many amps should be on a neutral? In this case, the current on the neutral would be 1 amp: 8 – 7 = 1. If both appliances pulled 8 amps, the current on the neutral would be 0. The goal is to have the current on the neutral be as low as possible—for safety, energy-efficiency, and other reasons.
People also ask, does the neutral wire have current?
The neutral wire in a circuit carries the same current as the hot wire. Current goes out to the load and must return. That's why the neutral wire must be the same size.
What is neutral current in single phase?
The neutral formula is used to calculate the neutral current. If the three hot conductors are equal, as in the case of supplying a three-phase motor, there is no imbalance and the neutral current is zero. In a single-phase system, the neutral carries only the imbalance of the two hot conductors, an easy calculation.
Related Question Answers
What happens if the neutral wire is not connected?
When the neutral wire breakage and phase-to-ground short circuit occur simultaneously, the displacement of the neutral point will be greater. The neutral is how the current flows back to the supply, so if you don't connect a neutral to one fitting it won't work. Can 2 circuits share a neutral?
A shared neutral is still allowed however, the way we treat them has changed. Circuits with a shared neutral must now be protected much the same as a 240 volt circuit. Can I use the ground as a neutral?
"Is it ok to use earth or ground as a neutral in AC?" No, you should never use a ground wire as a neutral. Yes, the ground wire will function as a neutral wire and the ground wire and neutral wire are bonded together at the panelboard. What is the purpose of the neutral wire?
Neutral wires carry currents back to power source to better control and regulate voltage. Its overall purpose is to serve as a path to return energy. Ground wires are electrical paths designed to carry fault currents when a power abnormality occurs. Can the neutral wire shock you?
No. By definition a neutral wire is a wire that is grounded to 0V. It does carry the current from the circuit back to the transformer however. If a system is wired correctly the neutral wire will never give you a shock. Why neutral has no current?
The current through the neutral wire is hardly ever zero, because the vast majority of circuits are single phase, and the neutral carries the same current as the hot wire. As there is no potential difference between the two ends of neutral in other words voltage at both ends is same, hence no current flow is observed. What happens to the neutral current?
The neutral carries current if the loads on each phase are not identical. In some jurisdictions, the neutral is allowed to be reduced in size if no unbalanced current flow is expected. If the neutral is smaller than the phase conductors, it can be overloaded if a large unbalanced load occurs. Which Colour is neutral?
Blue
Can a light work without neutral?
Yes, there are a few… (read very, very, very few) switches that don't require a neutral, but those will limit you to incandescent only. For those of us using LED, Fluorescent or some other energy efficient bulbs under 20w a neutral is REQUIRED! This is a diagram of a switch with the neutral run directly to the light. Is the neutral wire dangerous?
The power wire that is grounded is called the “neutral” wire because it is not dangerous with respect to exposed metal parts or plumbing. The “hot” wire gets its name because it is dangerous. The grounding of the neutral wire is not related to the operation of electrical equipment but is required for reasons of safety. Should neutral wire have voltage?
Some neutral-to-ground voltage should be present under load conditions, typically 2V or less. If the voltage is zero with a load on the circuit, then check for a neutral-to-ground connection in the receptacle, whether accidental or intentional. Reversed neutral and ground wires. Why did I get shocked on the neutral wire?
When you have power going to any part of your house, if there is any type of load on it,and you take the neutrals apart,you are interrupting the load so if you touch the 2 neutrals at any time you can become the neutral which is how and why you feel the shock. It can be harmful depending on the load. Why neutral current is high?
High neutral currents in buildings usually result from two situations. The first, and most common, is one where there are simply heavily unbalanced loads. In today's environment, it is becoming increasingly likely that high neutral currents result from some combination of the two. Does neutral have power?
A neutral wire is a type of wire in which carries currents back to the source of power and or regular voltage. Essentially, it allows power to return to its original source. Does the neutral wire go back to the power station?
Every electrical supply system uses a neutral conductor to return the current to the supply source. In addition, this neutral conductor is grounded. This approach creates a "path of low resistance" for the current to follow in returning to its source. Does neutral carry current in single phase?
yes. without a neutral a single phase is not complete. a neutral completes a single phase circuit. Can you downsize a neutral wire?
It is the 120 volt power that uses the neutral. Therefore the National Electrical Code allows the downsizing of the neutral in limited application. It is possible to downsize a feeder or service neutral according to the calculations in the National Electrical Code here: 220.61 Feeder or Service Neutral Load. Can two circuits go on one breaker?
When it's NOT a defect: Double tapped wiring is ok if the circuit breaker is designed for two conductors. If a circuit breaker is designed for two conductors, it will say so right on the circuit breaker, and the terminal of the circuit breaker will be designed to hold two conductors in place. What does a double 100 amp breaker mean?
It depends on what you mean when you say it has double 100 amp breakers. If you mean the breaker has 2 handles that are tied together and both handles say 100 amps then no it is only a 100 amp service. If you see 4 handles tied together then it would most likely be 200 amps. How much current is in a wall outlet?
In the U.S., a typical outlet is rated at 15 amps, 120 volts. This equates to about 1800 watts. Some outlets may be rated for 20 amps, 120 volts, or 2400 watts max load. Does the ground wire carry current?
Sometimes the neutral wire is referred to as a grounded wire. The grounding wire does not carry electricity under normal circuit operations. It's purpose is to carry electrical current only under short circuit or other conditions that would be potentially dangerous. Why does my neutral wire have 120 volts?
A neutral not connected somewhere can cause a reading of 120 volts on the neutral to ground. The voltage flow through any device that is plugged in. The device does not work because there is no current flowing. How do you calculate neutral current in single phase?
The unbalanced current on a single phase system is determined by subtracting the amperage on L1 from the amperage on Line 2. In the most extreme unbalance one of the lines will have zero current, so the neutral current will be equal to the remaining line. Can we connect neutral and earth wire?
The reason you should not connect these is that they serve two different purposes. The neutral wire caries current. It completes the circuit from the hot side. The ground (earth) wire is not meant to carry current. What size neutral is required for a 200 amp service?
200 A services are usually #3/0 copper. Sometime you can use a reduced neutral, sometime codes prohibit it. What size wire do I need for a 200 amp underground service? You need a minimum of #6 ground or #4 aluminum for 200 amps. How do you size a neutral?
Sizing the neutral: Sec. 220-22. You must size the neutral conductor to carry the maximum unbalanced current in the circuit (i.e. the largest load between the neutral and any one ungrounded phase conductor). You calculate the first 200A of neutral current at 100%. 
