Hi All,
After investing in an Huanyang HY03D023B VFD ( a 3KW one) a few years ago I finally came to use it. It worked fine several times and I was impressed and then a bang (not while running actually the motor) - no error message but clearly something bad had happened.
Having opened it I noticed a small section of track that connects to the ground terminal (furthest right) had blown out. I check the capaitors the three of them though paralled were fine on the capacitance meter.
Stupidly I decided to repair this track as no obvious damage could be seen elsewhere but at least to my not quite completely stupid strategy I repaired the blown track with fuse wire so that if there was another occurance it would not do too much damaged.
Guess what it blew again (the fuse link I'd installed) clearly something is wrong - well that much was obvious anyway before I tried to repair the board. No error meage appears on the display it thinks everything is fine apparently.
Fortunately no more damage was done trying.
Now to the question.
What is the best components to start checking (given no compnent is visibly damaged) what would cause the ground to carry so much current? Has anybody come across this problem involving the ground path?
P.S I have check for ground loops and run a earth loop test on the mains electrical and that was fine - good earth and low resistance.