How does an electric pen confirm ground and zero?
1, turn on the power, use the electric pen to measure, the one that will light up is the fire wire.
2,Disconnect the zero wire and connect only the fire wire, turn the lights in your home in the on position and measure with a pen, the other one that will light up is the zero wire.
3,The rest is the earth wire.
Zero and earth wires directly with
Pen can not be measured, they are not charged to ground, so the test pen will not be bright. Fire wire can be tested with a test pen.
In the case of residual current protection device (earth leakage circuit breaker), you can distinguish between the fire wire and zero wire by experimenting, connecting a light bulb between the fire wire and the zero wire, the light bulb glows normally, while connecting a light bulb between the fire wire and the earth wire, the earth leakage circuit breaker will trip immediately.
Household electricity, generally 220V ~ 250V single-phase electricity, from the fire line through the load such as light bulbs and other appliances through the zero line to form a circuit, the appliances can work properly. Part of the shell for the metal appliances, but also need to connect an earth wire, when the shell of the appliance accidentally charged can be led to the ground to ensure the safety of electricity.
In the wire arrangement and routine maintenance, in order to be able to distinguish between different uses of the wire, generally use different colours to distinguish.
Warm coloured wires are generally used for fire wires, the most common being red wires. If the pursuit of more standard construction, different circuits can use different colours of fire wire to distinguish, in addition to red wire, can also use yellow and green wire. However, the use of multiple coloured wires to differentiate to a certain extent will increase the cost of purchasing wires.
Zero wire is generally used for cold-coloured wire, the most common is blue wire, some also use black wire.
Ground according to the standard can only use yellow and green two-color line, because the ground is very important to the safety of electricity, so its colour requirements are very strict, can not use other colours of the line instead.
According to the colour points
Red fire wire blue zero line yellow and green two-colour earth wire
If the colour can not be distinguished
In practice, give you three lines, one is the fire wire, one is the zero line, there is a ground line, if the three lines of the same colour! How can you distinguish them?
1, the correct connection is: phase line (L) generally use red or brown; zero line (N) zero line with blue or green; protective earth line (PE) colour shall be used yellow and green line.
2, with an electric pen to measure the fire wire, will use a clamp-type ammeter? Phase line (fire) and the zero line of the current is the same, the ground line is normal when there is no current.
3, the zero line is a current flow; ground is for protection, no current for normal operation, only short-circuit and leakage current, the requirements of the grounding resistance is very small, the equipment end of the general shell protective grounding.
Measured with an electric pen out of the fire wire, the test lamp (with a line bulb) on the fire wire and the other two wires in a line, if the light is bright that is 0 line. If the light is not bright. Explanation is the earth wire. (Test light method, in the case of the ground line is not connected to the earth is effective, such as the ground line is connected to the earth, then regardless of the connection of that one line light will be bright .)
4, in the case of a power supply, find the firewire should not be difficult, difficult to distinguish between the zero line and ground, theoretically: the firewire and the zero line between the voltage in the 220 right, and the voltage between the ground line at 190 volts or so. Connect an energy-saving lamp, then the brightness should be able to see, bright nature is the zero line, just for reference.
5, there is a simple way
We are using a test light (with a light bulb) on the firewire and the other two wires in a line, if the light is on that is 0 line. If the light is on a leakage switch open jump. That is the ground.
