While having new wiring at your house, you should understand the roles of the different wires. The neutral wire is known to carry the current from the hot wire and send it back to the main power source. Generally, it doesn’t contain any voltage, but what if it got voltage?
Under normal circumstances, Neutral wires should have zero voltage. But, if your neutral wire has some voltage, there must be some wiring issues, defective electrical devices or systems, poor connections at the service panel, or a fault in the ground wire. Use a multimeter to check for the same.
If you cannot understand the real reason behind the neutral wire’s voltage, consult your electrician for fixation. This guide will help you know the reasons behind the problem and ways to fix the neutral wires.
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This post includes some affiliate links.What is a neutral wire?
There are three basic wires in electricity – hot, neutral, and ground.
Hotwire carries the current from the main power source and sends it to neutral wires.
Hotwires are mostly black and come in red, yellow, or blue.
Neutral wires carry this current from the hot wire, send it back to the main power source, and complete the full circuit.
The wires are usually white.
The neutral wires also connect to the ground wire at the main panel, meter, street drop, and step-down transformer.
The ground wire is a safety wire through which electricity flows during accidents and short circuits and saves you from electrocution.
Ground wires are green wires.
The ground and neutral wires are very closely related because the neutral point of the electrical supply connects to the ground wire.
Do neutral wires have voltage?
Generally, neutral wires are said to have zero voltage.
But if you ever touch the neutral wire on a live system, you will receive a shock.
Having zero voltage is very different from having no electricity.
Each phase in the circuit has different voltages relative to the neutral of 115V in the United States.
That is why the neutral wires are said to have zero voltage.
The amount of electricity flowing through the neutral wire differs depending on the system.
Two similar systems can have different requirements if they are in different locations.
The reason could be the poor connections between the neutral and earth wires or poor electrical devices and systems.
Though neutral wires should have very low voltages, it is not safe to touch them bare.
It is very dangerous to work with neutral wires while they work perfectly in an electrical system.
Why does my neutral wire have voltage?
It is said that neutral wires have zero voltage, but that is not completely true.
Since it carries the current from the hot wires and sends it back to the main power source, it does have a slight voltage.
However, the voltage of the neutral wires can be unexpectedly high in certain circumstances.
It can lead to overheating of your plugged-in appliance.
Heavy and unbalanced load
If a 3-phase system with a dominant load of being a single-phase, it carries an extremely unbalanced current.
When the system changes, the loads in the phase become unbalanced, increasing the voltage in the neutral wires.
Only fully loaded currents are considered when the current load is distributed evenly within the panel.
If the current load is too much, it causes an unbalanced load for which the neutral wires get high voltage.
Other situations where the loads get unbalanced are during the diversity of the loads in your panel.
It causes a huge imbalance which increases the voltage in the neutral wires.
However, diversity rarely causes the voltage to increase in the neutral wires.
If diversity is the real problem, your neutral wires can have high voltages and burn out in the worst cases.
Harmonic distortion
Harmonic distortion occurs when the current waves are not in their form anymore.
When this happens, the neutral wires receive excessive-high voltages.
If you suspect this, use an RMS meter instead of a normal ammeter or voltmeter to determine the issues.
You can see the unusual harmonics over the screen of these devices.
Neutral wire removed
If you have removed the neutral wires from the neutral bus bar of your panel, you will see that the neutral wire has around 120VAC.
Besides, if you have connected any turned-on load device to the circuit, the neutral wires will also have high voltages.
Neutral and hot wire reversed.
If you find that your neutral wires have around 120V, but the voltages in the hot wires are less than 120V, then both wires are reversed.
Typically, a 2-volt or less is the normal load.
Defective wirings
There have been some defects in the wirings for which the neutral wire voltage can increase to a great level.
Broken wires in the circuit can heat the wires and increase the voltage of the neutral wires.
High voltages
High voltages beyond the standard household level and excessive current flow can heat the neutral wires.
Voltages beyond 240V to 250V can cause short circuits for which a huge amount of voltage is forced out from the passage.
This short circuit can heat the neutral wires and increase their voltage unexpectedly.
Excessive current
When the circuit breaker has excessive loads than it can handle, it causes the neutral wire to have too many voltages.
A circuit breaker should not exceed 80% of the rated load.
If the load draws more currents than the fuse can handle, excessive current will flow through the neutral wire, which will have high voltage.
Ground wire fault
If there is a ground wire fault, the current will flow through the ground to the neutral wires.
It will put more strain on the neutral wire, for which the wire’s voltage will highly increase.
Single-phase vs. 3-phase
In the single phase, the electricity is carried by the hot wire from the main power and then transferred to the neutral wire.
The neutral wire carries back to the main source and completes the circuit.
That is why there is some voltage in the neutral wires.
In a 3-phase, the electricity follows the minor resistant path, but there is more than one return route of the current to the main source.
So, there is voltage in all three of the phase wires.
The neutral wire doesn’t have voltage here because the neutral wire is not the path of the least resistance.
How to understand that the neutral wire has high voltage?
Improper and defective wirings, poor connections, and defective electrical devices are some common causes behind voltage in the neutral wires.
Check it with a voltmeter if you suspect high voltage in your neutral wires.
Consider doing the following things before you try to fix the issue:
- Measure the neutral ground to hot ground wires. If the neutral ground shows more voltage than the hot wires, the wires must have been reversed.
- Typically 2-volt or less is normal. If the neutral ground voltage is zero, check the neutral connection in the receptacle.
- To check the neutral and ground loads, check which one is greater. If the ground has greater loads than neutral, you must have switched the neutral and ground. Correct the wirings immediately.
Also read: Can Live And Neutral Be Connected Together? (+Possible Hazards)
How can you fix a neutral wire with high voltage?
Once you determine the problem, you must fix the problem as soon as possible.
Before you try fixing the issues, you should know certain things for safety:
A panel has 240V power, 120V split in two to receive a total 240V supply.
The hot wires provide electricity to the panel.
Large appliances, like the stoves, need 240V to function.
The circuit will be complete when the large device is joined with two wires.
Smaller appliances need 120V to function, thus requiring neutral wires.
Here are the ways to fix a high-voltage neutral wire:
Check the voltage first.
An outlet must have zero voltage from neutral to ground and 120V from hot to the ground.
Check it with your voltmeter or multimeter.
If the neutral has 120V, it is unplugged.
Switch off the power
Switching off the main power is important when you opt to work with electricity.
It keeps you safe from electrocution and short circuit.
It is a useful safety precaution; you must follow it when working with electrical things.
Remove the outlet’s cover.
Unscrew the nuts holding the outlet using a screwdriver.
Now, remove the cover after removing the screws.
Check the voltage
Make sure there is no voltage in the circuit.
To check this, use a voltage tester after opening the outlet.
When you check it, the tester should show zero results.
It means there is no voltage.
If the tester shows there is still voltage, check that you have properly turned off the circuit and the main switch.
Remove the receptacle
Now, unscrew the receptacle after removing the outlet cover and confirming zero voltage in the circuit.
Now, unscrew the screws holding the receptacle with a screwdriver.
Check and correct the neutral wire condition.
See what is wrong with the neutral wire: whether it is open, broken, or poorly connected with the terminals, etc.
If there are broken or old wires, replace them with a new and good one.
Fix the unbalanced load
If the neutral wires get high volts due to unbalanced or heavy loads, you must power the loads from a phase that allows a proper balance by rewiring some loads of the panel.
If it is wire diversity, check it with a power monitor to find out the load swing levels and then rewire them for a good balance.
Distorted harmonics
Find out the issue with the help of an RMS meter.
If the problem is distorted harmonics, ensure that there are no shared neutral cables in the branched circuits.
Remove the shared neutrals to balance the harmonics.
If you cannot remove the shared neutrals, swap them with larger ones to avoid overheating the neutral wire.
If none of the two works, install an active or passive filter to decrease the distorted currents.
You will have to use transformers to reduce the distorted harmonics.
Fix wire reversion
Sometimes, hot and neutral or neutral and ground get reversed, for which the neutral voltage increases.
When you open the circuit and find any such thing, bring them in place.
It will stop the neutral wires from having such high voltages.
Replace the receptacle
Once you have confirmed the issue, keep things in place.
If required, you can replace the receptacle.
Remove all the wires from the receptacle, replace the old receptacle with a new one, and then put all the wires properly.
If the wires are badly disorganized or getting twisted, keep them in a place and tie them with wire tie cable, so they remain in one place.
Safety measures to take while fixing high voltage neutral wire
While you try to fix neutral wires with increased voltages, you must follow certain precautions to prevent short circuits and electrocutions.
Dealing with electricity can be dangerous if you do not follow certain guidelines.
Electrical cords, overloaded circuits, water near the electrical devices, plugged-in appliances, loose and broken wires, and outlets, and many more can cause electrical issues.
You should check these things before you start working.
Here are some important safety measures for you while working with electricity:
Make sure the outlets are not overloaded.
Outlets serve us with enough electricity.
They have enough plug-ins to put up chargers for phones and laptops, computers, televisions, and several other devices.
Plugging in so many devices together can overload the circuit.
So make sure you unplug them before working with the electrical wires.
Besides, using so many plug-ins together is unsafe as overloading can lead to fuse blow.
Also read:
Use proper watts for lights and appliances.
Use lights within the wattage your light fixture has.
Using light with more wattage than your light fixture can handle results in several electrical issues.
A 60-watt or less than that would be a good one.
A 25-watt light is good for unlabeled ceiling fittings.
Keep water away from electrical things.
Water can conduct current, and mixing them is not a good thing at all.
There are high chances of fuse blow, short circuits, electrocutions, etc.
Keep all the electrical cords, devices, circuits, outlets, and equipment away from water.
Before you start working, ensure that your surroundings and hands are always dry.
Wear protections
Wear gloves and goggles before you start working with electrical things.
Normal gloves are not meant for electrical purposes. Use thick nitrile gloves, like:
- Heavy duty gloves, Infi-Touch, Strong and Tough
- Disposable Nitrile Gloves – Latex Free, Powder Free Medical Exam Gloves
Change your electrical wirings from time to time.
Electrical cords can get old over time.
And old wires are very dangerous as they become weak and fail to carry enough current as they used to before.
Changing the wires from time to time can prevent several electrical issues.
Also, ensure that the new one you use is in good condition.
Check for tears or breakages and avoid such wires.
These wires can cause electrical issues, like short circuits or fuse blows.
Final thoughts
Generally, neutral wires have little or zero voltage, but if it has very high voltage, there might be some issues.
You must find the problems and fix them as soon as possible.
Though neutral wires don’t have voltage, they do have currents.
Both are not the same.
So, handle them with care.
While dealing with electrical wires, always take proper precautions and then start working.
If you can’t figure out the problem behind high voltage in the neutral wires, call an experienced electrician to solve the issue.
FAQ
Why does my neutral wire have 120V?
If your neutral wire reads 120V, it indicates an open neutral.
The reasons could be a poor connection in the service panel, wiring, or a fault in your electrical system.
You must find the reason and fix it as soon as possible.
Reference: BASICS OF HOME ELECTRICAL WIRING, Electrical wiring Wikipedia.
