Why is it wrong to say that the circuit must be electrified when the electric pen shines when checking with the electric pen?
The luminescence of the electroscope (electric pen) can indicate that there is a voltage (above 60V) to the ground, but it cannot indicate that there must be a current. When we usually say that there is electricity, it means that there is current in the line, because the load can only work when there is current.
There will be induced electricity in the circuit, and the neon bulb of the test pen will emit light as long as the voltage exceeds a certain range, so the light emission of the test pen is not necessarily caused by electricity in the circuit, but may also be induced electricity. Moreover, some electrical appliances will have induced electricity, which will also cause the test pen to shine.
Extended data:
1. Before using the test pen, first check the test pen to make sure its function is normal. We can test it on a known power supply to see if the neon bulb glows. We also need to check whether the pencil is damp or flooded to ensure our own safety.
2. Before entering the electric field test with the test pen, check whether the voltage in the place is applicable. Don't try to test the voltage higher than the applicable range with a pencil to avoid danger.
3. When using the test pen, don't touch the metal probe at the front end of the test pen by hand to avoid electric shock accidents; When using the test pen, you must touch the metal plate or hook at the end of the test pen with your hand. If this is not done, although the neon bulb of the test pen does not emit light, it will be very dangerous to correctly judge whether the charged body is charged because the charged body, the test pen, the human body and the earth have not formed a loop.
4. When using the test pen in bright light, we should pay special attention to judging whether the neon bulb of the test pen really shines. Many accidents are caused by careless misjudgment, so we must avoid it.
5. It is best to wear insulated shoes when using the test pen to prevent problems before they happen.
6. When judging in-phase electricity or out-of-phase electricity, it must be remembered that both feet must be insulated from the ground. It is the same whether both pens are bright or only one pen is bright. Not bright is in-phase electricity, as long as it emits light, it is out of phase electricity.
7. When testing high-voltage equipment with a test pen, first of all, the operation monitoring system must be strictly implemented. While someone is operating, one person is in charge of monitoring. The operator should be in the front and the guardian should be in the back. When using the test pen, we must pay attention to the adaptation of the rated voltage and the voltage level of the electrical equipment under test.
8, check the electricity, the operator must wear insulating gloves, put on insulating shoes, in order to prevent contact voltage damage to the human body. The operator should first check the test pen on the electrified equipment. When conducting live inspection on multi-layer lines, it is necessary to check the low voltage in advance, and then test the high voltage, and the upper layer should be first and then the lower layer.
