Why is it wrong to say that when you use a test pen to check, the light of the test pen means that the circuit must be charged?
The luminescence of the voltage tester (electric pen) indicates that there is a voltage (above 60V) to ground at that location, but it does not necessarily mean that there is a current. And what is usually referred to as having electricity means that there is current passing through the circuit, because the load can only work when there is current.
There will be induced electricity in the circuit, and the neon bubbles of the test pen will emit light as long as the voltage exceeds a certain range. Therefore, the light emission of the test pen is not necessarily caused by electricity in the circuit, but may also be induced electricity. And some electrical appliances may have induced electricity, which can also cause the voltage tester to light up.
1. Before using the voltage tester, it is necessary to first verify its functionality to ensure that it is functioning properly. We can conduct tests on a known power source to check if neon bubbles emit light. We also need to check whether the voltage tester is damp or has water to ensure our own safety.
2. Before using a voltage tester to test the electric field, check if the voltage at the location is suitable. Do not attempt to use a voltage tester to test voltages higher than the applicable range to avoid danger.
3. When using a voltage tester, do not touch the metal probe at the front end of the tester with your hands to avoid electric shock accidents; When using a voltage tester, be sure to touch the metal piece or hook at the end of the tester with your hand. If this is not done, although the neon bubble of the electric tester does not emit light, it cannot be correctly judged whether the charged body is charged or not because the charged body, the electric tester, the human body, and the ground do not form a circuit. Once a misjudgment is made, it will be very dangerous.
4. When using a voltage tester under bright light, special attention should be paid to determining whether the neon bubbles of the tester are really shining. Many accidents are caused by carelessness and misjudgment, and we must avoid this.
5. It is best to wear insulated shoes when using a voltage tester to prevent problems before they occur.
6. When determining whether the electric current is in phase or out of phase, it is important to remember that both feet must be insulated from the ground. Test with both hands holding the pen, whether both pens are lit or only one is lit, it is the same. Not illuminating is in-phase electricity, as long as it emits light, it is out of phase electricity.
7. When using a voltage tester to test high-voltage equipment, it is necessary to strictly follow the operation supervision system. While someone is operating, one person must be present to supervise. The operator should be at the front, and the guardian should be at the back. When using a voltage tester, it is important to pay attention to the compatibility between the rated voltage and the voltage level of the tested electrical equipment.
8. When conducting electrical testing, operators must wear insulated gloves and insulated shoes to prevent contact voltage from causing harm to the human body. The operator should first inspect the voltage tester on the electrified equipment. When conducting live testing on multi-layer circuits, it is necessary to first test the low voltage before testing the high voltage, starting with the upper layer and then the lower layer.
