# Does neutral wire need to be same size?

By code, the hot wire, neutral wire and ground wires all need to be the same guage. That gauge as determined by the load current. The neutral has always had to be the same size as the hot lead because all of the load current returns through it.

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%.

Also, how many amps does a neutral use? That way, the amperage of the two circuits cancel each other out when the power returns to the utility on the 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.

Also question is, can you downsize a neutral wire?

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. (A) Basic Calculation. The maximum unbalanced load shall be the maximum net calculated load between the neutral conductor and any one ungrounded conductor.

Should there be current on neutral?

The neutral wire is a conductor that should be at ground potential. It is the return path for any single-phase loads. So in an American house, any particular wall outlet is 120v, fed by a phase wire (black) with the return on the neutral (white). The ground (green) is there for safety and should not carry current.

### Does current flow through the neutral wire?

Normal circuit currents flow only in the neutral, and the protective earth conductor bonds all equipment cases to earth to intercept any leakage current due to insulation failure. The neutral conductor is connected to earth ground at the point of supply, and equipment cases are connected to the neutral.

### Why is neutral wire thinner?

The returns for all three phases are combined together to form the neutral wire. So result is that the net current in the neutral is usually smaller than the currents in the live wires. If the current is smaller then the resistance can be increased by using thinner wires without too much of a loss of energy.

### Why is neutral wire needed?

The neutral wire is often confused with ground wire, but in reality, they serve two distinct purposes. 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.

### Why are neutral and ground tied together?

The reason that one of the power wires is named “neutral” is because it is connected directly to the building ground connection at the circuit breaker panel. Therefore it is connected directly to the grounding (third) wire.

### How do I calculate wire size?

Divide the voltage running through the cable by your target current. If, for instance, 120 volts will act on the cable, and you want 30 amps to run through it: 120 / 30 = 4. This is your target resistance, measured in ohms. Multiply the cable’s length by its material’s resistivity.

### How do you determine neutral current?

To calculate the neutral current flowing in a three phase star connected system (Sinusoidal load)… If the three phase currents are equal to one another, then the neutral current is zero. If one of the phase currents is different (higher or lower) than the others, then the neutral current is equal to the difference.

### What size neutral is required for a 200 amp service?

It really depends on the electrical codes in your area. 200 A services are usually #3/0 copper. Sometime you can use a reduced neutral, sometime codes prohibit it.

### How do you calculate neutral current?

Note the neutral formula. If A, B and C are the three phase currents, the formula to find the neutral current is the square root of the following: (A^2 + B^2 + C^2 – AB – AC – BC).

### What is an unbalanced neutral?

ANS) Neutral wire is a return path for unbalance current. Electrically neutral is zero potential with respect to live potential. It provides a low impedance path for the fault current to flow to the ground, instead of our body and thus saving us from dangers of electrocution.

Load (usually black, sometimes red): is a continuation of line and goes out to downstream devices. Non-GFCI circuits will not have a load. Neutral (usually white): completes the AC circuit and carries excess current to ground. Ground (bare): carries any inadvertent current away from the circuit in case of a fault.

### Can the ground wire be smaller?

The grounding conductor may be larger than this minimum requirement, but should not be smaller.

### Why does my neutral wire have voltage?

Because the resistance of the copper neutral wire is usually very near zero, this also keeps the voltage low. However, if the neutral wire is damaged or has a high impedance fault like a corroded connection, the voltage in the neutral can increase to a dangerous level at some point out in the branch circuit.

### Does the white wire carry current?

White and gray electrical wires can only be connected to one another. While they’re called “neutral” wires, they may still carry a current, especially if the load is unbalanced, so handle them cautiously.