What a great job for you and your guys to have in your repertoire.
It's weird, it's new, and it keeps me feeling young.
Kinda fun to rig it out of the shaft, finding/inventing new processes along the way. A brother helped, explaing how to get the ropes out of the machine. My esteemed "associate" also came up with some great ideas. And then I took credit for all of it! 8^)
This stator didn't implode, and throw copper balls all over. But it is shorted in one area. Each leg read about 1 ohm to ground, compared to where a good motor on an other running car reads very high K ohms, or megs, when checked in the exact same way. I had Rubin come out and double check my findings, and he confirmed the stator is shorted, as did the manager of the shop that the motor is at.
The short seems to be on the far side of a good bit of winding turns. Although we were reading only 1 ohm to ground, the motor windings will read very low, as they are very thick. So it's not like the output of the drive was feeding into a direct short, there was still a lot of winding turns, and some impedance, too. There was enough magnetic force generated through the remaining good part of the windings, for the motor to turn a few degrees at a time. But the current draw was very high, and the drive would crowbar itself off, on the max current parameter. And then as soon as the current subsided, the drive would turn on again, the car would move again, and then just as suddenly, it would crowbar to a stop again.
Only this effect happened very rapidly, in staccato succession, alternately trying to turn the motor a bit, then letting off, and the net result was a rapid pounding felt through the platform, motor, everywhere, sort of like a jackhammer.
The current limiting capabilities of the V3F25 drive allowed a certain amount of current flow, and at the same time acted like a safety valve. It would turn the motor just a bit at a time, but no fuses would blow, nor critical drive fault to keep it shut off.. Weird effect.
This near instantaneous crowbarring may have kept the windings from blowing into smithereeens, like you get when driving a hydro motor from an across-the-line starter, or the ac end of a gen set. I know what you mean, I'm used to seeing molten copper after a blow up.
Did you get that MX 20 back in OK....
A tip.. make sure that you get her sitting down nice and square on that guide mounted plate with the TICO pad before you take you tackleout, the sheaves wear like a ------- and you get relly rough ride quality.....
but you knew that already...
All the best
Agtrak100
We had to wait an eternity to get new motor bearings for it. Seems these
bearings are not available just "off the shelf", and must be special ordered.
I've got to put the motor back in now, so your advice came just in time, thanks.
Is the resolver angle easy to adjust?
I've not had to take a motor right out..... YET... just re-roping
however...
hopefully you have slung it from the top so that you can swivel the motor... the problem that we had was keeping the incoming power cables and Tacho clear of lifting and slinging gear... you need to get her so that she drop down true on the mount that supports the bottom of the motor, the outer falnges of the motor should be evenly/ truely aligned with the outer flanges of the bracket on te guide rail...
I will try and post a pic or two.....
On the bigger KONE units you can also get that big latching bar scrapping up the back of the motor body if the motor is out of line
Agtrak100
we have a hose pipe ban and it is raining cats and dogs... only in England....
As it turns out the bearings are not readily available, and had to be specially ordered from Europe.
When we took the motor to the job site today, we left it in the bed of the truck. We backed the truck up to the controller, hooked up the 3 phase, resolver, thermostor, jumped a bunch of stuff out, temporarily changed some parameters,
and then it ran!
Tomorrow we install it for real.