Multimeter how to measure the insulation protection layer of the wire
A multimeter is only capable of ordinary measurements of voltage, current and resistance or other. The multimeter is not capable of measuring the insulation of wires at all.
Wire, cable are by the local Quality and Technical Supervision Bureau or testing centers to use special testing equipment, or commissioned by the manufacturer to test their own.
According to GB/T5023.3-2008 standards for example; generally used polyvinyl chloride (PVC) copper-core wire or power cable BV450/750 1 × 1.5 wire, it requires a length of 5 meters in a specially customized tank, so that the water temperature is gradually warmed up to for (temperature 70 ± 2 ℃) immersed for no less than 2 hours, the insulation resistance value should be measured with a The insulation resistance value should be carried out by applying the corresponding DC voltage on a professional testing instrument. Such a process should be divided into a total of 5 times to carry out.
The DC voltage of the internal power supply battery of the multimeter used by people is usually 9V, which is not sufficient to determine and test the insulation of wires.
Cable insulation is best measured with a shaking table, the results of the multimeter measurement is not allowed, only valuation. But the cable insulation is seriously damaged, with a million meters to measure or more convenient to find out the problem. Resistance between the lines must be greater than 1M ohms, such as less than 1M, be careful when using, but must exclude the cable into the water or moisture, if any, it must be sun-dried and then measured.
Multimeter test filter good or bad
If the filter internal circuit, then, the inverter will stop working, because the filter is generally connected in series on the power supply of the inverter.
If the filter fails, it may cause interference to the equipment around the inverter, which may cause the elevator to work abnormally, or the equipment around it can not work properly, there are noises, abnormal movements, etc., in serious cases, it will lead to the destruction of these sensitive electromechanical equipment.
