220v power supply why both wires have power in the electric test
The electric test pen is a tool used to distinguish live wires and neutral wires. When using it, human hands touch the metal body at the end of the pen, and the metal body at the tip of the pen touches the wire or the conductor connected to the wire. If it is a live wire, add 220V to the electric test pen and the human body. Voltage, there is a current flowing into the earth through the test pen and the human body, and the neon tube of the test pen emits light; if it is a zero line, there is no voltage at both ends of the test pen and the human body, and there is no current, and the neon tube does not emit light. However, the test pen does not emit light when it touches the neutral line neon tube. When the circuit is normal, when the neutral line of the incoming household line is disconnected, as long as the switch of one electrical appliance is closed, the circuit is blocked, but the neutral line in the home will be closed. However, it is charged through the indirect connection between the electrical appliance and the live wire. When the electric measuring pen touches the zero line, a voltage of 220V will be applied to the two ends of the electrical appliance, the electric measuring pencil and the human body, and the current will pass through the electrical appliance, the electric measuring pencil and the two ends of the human body. The human body flows into the earth, so the neon tube will also emit light.
It should be noted that at this time, although the electrical appliances cannot work, they are dangerous to people. Because if a person stands on the ground and touches the zero line, the 220V voltage will be applied to both ends of the electrical appliance and the human body, and the resistance of the electrical appliance is generally much smaller than the resistance of the human body, and most of the voltage will be borne by the human body, that is to say, it will be applied to the human body. The voltage on the battery is much higher than the safe voltage, so if the human body contacts, an electric shock accident will occur.
How to use the induction test pen
The induction test pen can measure both AC and DC. When measuring a DC battery, you need to touch the other pole of the battery with the other hand. The range shows 12v, 24v, 36√, 110v, 220v. When measuring the presence or absence of electricity, it can directly display the voltage. It can be used in the same way as the old-fashioned neon bulb electric pen. When measuring the breakpoint of the cable, connect the suspected line to the live wire. The pen will display 12v, and when the breakpoint is reached, the display will disappear, move back and forth, determine the position, and find the breakpoint. This is the biggest advantage of the induction pen over the old-fashioned neon bulb test pen, but remember to connect other wires to the neutral line , otherwise, due to the induction effect, there will be electricity everywhere, and the breakpoint cannot be found, and it may not be detected for new cables with good quality.
It can measure alternating current and direct current. When measuring a direct current battery, you need to touch the other pole of the battery with the other hand. The range shows 12v, 24v, 36√, 110v, 220v. When measuring the presence or absence of electricity, it can directly display the voltage. It can be used in the same way as the old-fashioned neon bulb electric pen. When measuring the breakpoint of the cable, connect the suspected line to the live wire. The pen will display 12v, and when the breakpoint is reached, the display will disappear, move back and forth, determine the position, and find the breakpoint. This is the biggest advantage of the induction pen over the old-fashioned neon bulb test pen, but remember to connect other wires to the neutral line , otherwise, due to the induction effect, there will be electricity everywhere, and the breakpoint cannot be found, and it may not be detected for new cables with good quality.
