eejacky
Electrical
- Oct 26, 2002
- 19
Dielectric test, Meggar test and ductor test are to be carried out for every new installed LV switchboard assemblies. However, I don't know the basic principle behind these.
For meggar test, 1000Vdc is applied with one end to one phase (say R Phase) of busbars while the other end to shorted (Y,B and neutral) busbars. The question is: what is the reason for meggar test?
Why we need to short the three phases?
Why DC voltage is used?
Why 1000V is used? (I heard a engineer said this value can be derived)
For ductor test, we need to measure the resistance of contacts for two times (one for first half cycle, the other for 180o out of phase cycle). Why we need to do do? For static busbar contacts, it should come out the same result even though the polarity of current reverse.
The last question is what is the difference between dielectric test and meggar test?
For meggar test, 1000Vdc is applied with one end to one phase (say R Phase) of busbars while the other end to shorted (Y,B and neutral) busbars. The question is: what is the reason for meggar test?
Why we need to short the three phases?
Why DC voltage is used?
Why 1000V is used? (I heard a engineer said this value can be derived)
For ductor test, we need to measure the resistance of contacts for two times (one for first half cycle, the other for 180o out of phase cycle). Why we need to do do? For static busbar contacts, it should come out the same result even though the polarity of current reverse.
The last question is what is the difference between dielectric test and meggar test?
