When measuring between the neutral wire and the ground wire with a multimeter, there is a voltage of 220V.
This situation may occur due to messy wiring, the lack of color - coding for wires, or the stubborn belief in the "left - neutral, right - live" rule.
The solution is simple. Since you have a multimeter at hand, use it to measure the resistance and voltage between the three wires respectively. Re - identify which wire is the live wire, which is the neutral wire, and which is the ground wire, and mark them properly. Then you won't make the same mistake next time.
Break in the neutral wire
It is best to measure the voltage at the power circuit breaker. If possible, it's even better to measure at the electricity meter. If you measure at the back - end of the equipment, there may be a break in the neutral wire, leading to misjudgment.
When the back - end neutral wire is broken, the live wire and the neutral wire will be connected through the filament or the coil. Although there is some resistance, it can basically be ignored, and the measured voltage doesn't change much. In this case, you need to remove electrical appliances such as light bulbs to break the circuit between the neutral wire and the live wire for an accurate measurement.
High resistance of the neutral wire
This situation is basically caused by loose crimping and poor contact. However, the voltage measured in this case is unstable, and the wire joints will be hot.
The equipment casing is charged
If the equipment casing is charged, that is, the live wire is leaking electricity, and an ordinary air switch is used. If the leakage current does not reach the short - circuit current, the air switch will not trip. In this situation, when measuring between the neutral wire and the ground wire, there may be a voltage of 220V.
Or, even if a residual current device is used, but the ground wire is broken or the grounding resistance is too high. When a leakage occurs in this situation, measuring between the neutral wire and the ground wire will also show a voltage of 220V.
Reverse connection of the ground wire and the live wire
Although it's hard to imagine such a strange situation, when analyzing the problem, we have to take it into account and not overlook any doubts.
