The other day I was called out on a scene to look at a situation that was brewing. A problem with a motor operation that was incomprehensible. After doing some studies on the inverter drive's operation, I then understood why they were having such an issue resolving this "Inverse Time" error that was popping up.. Now I'd rather sit at the bench and play with circuits and build things how ever, this peaked my interest.
So I decided I needed some exercise any way, and commenced to go on the roof of our facility to inspect a possible motor miss wiring.. Well, first I found L3 wire had burned off. That was fixed how ever, now the drive is over currently only on L3 but not on L1 and L2 and thus refused to get up to speed. So.. more checking. Meg the motor, nope, that seems fine. Then scratch my head, nope, that didn't solve anything either. Then I decided to do something outlandish. I examine the wire numbers printed on the leads and started to ohm them out. What I found was shocking! the dame motor had the wrong numbers on the leads from the factory! Now these are printed numbers on the wire not tags.
Where you're suppose to have 7,8 and 9 in the Star/Y set, it wasn't! 7 and 9 were linked and 8 was linked with 3 and 1,2,4 and 5 also all linked, one of them has zero ohms..so, that was a Hmm..
I won't advertise the maker of the motor here but it is a heavy duty type for harsh environments just put in about a year ago and it never ran correctly. But since it's only used for cooling water using out side air, no one really jumped on it until recently.
We will be checking the new motor before it gets installed, that is a big ordeal and change this how ever, I won't have to worry about the grunt work! :)
Jamie..