hey self thanks for the reply. we only added 2x 20lbs test weights along the centre frame which seemed to do the trick.also when you say all done thru the controller im assuming the basic side on the level controller and display not the drive cabinet in the shaft?plus we were under the impression that after a certain amount of runs the controller locks out as a pain incase they lost the contract? this is coming from some kone guys and its them that said you need a test tool to open them up again.

cheers mate thanks.

thanks chit i will jot this down and when i get a chance have a look at it. unfortunately getting test weights from construction needs finessing as we install alot of new lifts and they always seem used. i will try.

thanks for the write up mate cheers.

chit this is for a monospace lift? as i spoke to a couple of guys and they said to zero the lift then pin the lift on the top floor and try to drive it on maintenance. not the full procedure as im getting this info second hand. self was this the way you did it?

cheers guys thanks for the help.

I've been to Moline Ill. several times for training and never heard of a lock out. Maybe outside the US they have something like that but not here.

i will get the procedure and let you know.

Have and MX10 with TMS50AV that has a grinding noise in motor. I have changed tach with new and checked brake clearances. I assume the motor is going out. Has anyone elese heard of this? Can these be rebuilt or am I looking at a new 40k motor.

See post about the perfect business plan.
http://www.vatortrader.com/forums/ubbthr...h=true#Post4091

Kone wanted an absolutely huge amount of money for an MX 20 that was water damaged. Much, much more than you have stated. We removed it, rewound it, replaced the bearings, and re-installed it. Then did the construction/commisioning start-up, resolver angler, tach polarity, tach voltage, shaft learn, adon learn, brake adjustments, full loadweighing calibration, etc, etc. When we were done, we had a fine running machine! We did it for far less than half of what $ Kone wanted. The customer was convinced that the MX20 was a space ship, wound by aliens, and defied analysis! We proved them wrong, and will do so again. Elevator brothers all over the world contributed much to this effort, thank God!

When we were done, it would roll back, (roll up) on each and every stop. I got scared for an instant, thought "OH, sh*t, somethings' wrong with the rewind". But I don't get scared so much my mind turns off. I'm gonna keep punching until either I win, get k/o'd, or the final bell sounds. It's just an elevator, after all, just nuts and bolts, and wires. It's not a UFO. We can learn, we can understand, we can fix it. We have the technology!

It would come to the floor very controlled, in the normal way. Then the brake would set, and the drive contactor would drop out. During that instant, the car would roll up an inch or so. All the helpful experts were focused on brake issues, and who could blame them? It was the most probable cause for the problem. After exhausting all brake adjustments and remedies, I started to suspect the timing of the brake drop. (But meanwhile I got pretty good experience adjusting those brake pods! Heh heh!)

The drive board has little LEDs, that say "Contactor", and "Brake" on them, and the brake led indeed would go dark first, (just like it did on a good running car), meaning that the motor would hold the car for just a sec, while the brake mechanically set. And indeed, they were sequenced correctly. The only problem is, that with an oscilloscope, you could see that the command from the drive board to the main brake module wasn't crisp and definitive, and since it was going grey, rather than going to 0 volts, the brake module wouldn't set quick enough. On one channel on the scope, you could see the command to drop the brake, and on the other channel, you could see the command to drop the main contactor. The brake command out of the drive board feeds into the brake module. The character of this command is important. It doesn't like a "roll off", rather, it needs a crisp sqaure corner to the drop of the pick command. The brake command WAS going low, before the main contactor command went low, and the brake WAS setting, (and setting hard at that!). We had the sheave so clean, and shoe gap so low, ...everything so clean....it couldn't possibly be the brake itself. But it wasn't setting fast enough. (and not for a mechanical reason) Although the LEDs on the drive board showed the drives' intention of dropping the brake, before dropping the drive power to the motor, it wasn't so. Can't let the LEDs fool ya....

This delay in the drop of the brake coil voltage provided just a little window of time for gravity to pull the counterweight to the earth, making the car roll up an inch or so. Changing the drive board fixed the problem.

The roll back problem wasn't related to the motor work, just incidental. Another weird thing was this- While the water-damged motor showed 0 or 1 ohms to ground, on all three legs, the drive current limit would allow a bit of current flow, before crowbaring itself off. Then it would turn on, then off, then on, at a fast cyclical rate. This set up a staccato mechnical pounding, both in the motor, the car, the control, everywhere. This might have introduced spikes and noise, that stressed the drive board, causing it to have problems. That was actually almost more interesting than changing the motor, fixing that brake timing issue. That's why I love my oscilloscope! Can't see that sh*t with a meter.

Here's my thread on it at ElevatorShack, a European elevator site. I also posted it here, but I think this thread has more pictures. Early on, some of those guys actually said that only Kone could do it. But we made beleivers out of 'em!

http://elevatorshack.com/forums/index.php?/topic/3257-how-do-you-remove-a-kone-mx-20-flatmotor/

I'm almost ashamed at how long my post above is!

What can I say? I like to write!

(and toot my horn!)

Very nice! Im glad your post was long-there is nothing in the world like fixing what a lot of folks would say is unfixable

Awesome job and post Vic, I enjoyed reading them in both forums!

Thanks for the input Vic. I am pulling the motor today. Was the bearing replacement of MX 20 done by a motor shop and was it straight forward? Where they able to get correct bearings or did you get them from Kone Spares?

The motor shop had to get the bearings from Europe. At least that's what they told me. You know how it is, everybody circles the wagons, and sits on information, so as to protect their business interests. I've got the old bearings still. When I get back, I'll dig for the source. It'll be a few days, as I'm out of town.

They had to make a custom puller, to pull the rotor straight up and out of the stator housing. The neo-dymium boron-oxide magnets are very sensitive to heat, and impacts. Brittle stuff. And very powerful, don't get pinched, would be a real bad day...

The puller was just some flat plate, with holes on the periphery to bolt to the rotor, and a hole in the center for an eye-bolt. Just iron mongery. Have torch, will travel, no problem. They bolted the stator down to secure it, then lifted the rotor straight up with the shop crane. Make sure a keeper of some sort is put on the magnets. They used some banding iron.....

You can't test the rewind on 60 cycles!
You can't even test it on a VVVF drive! (according to the motor shop)

It operates like a big stepping motor. If I understand it right, the V3F25 drive uses the resolver angular input to determine the degree of rotation of the rotor, and it energizes the 3-phase windings accordingly. It applies like more of a "pulse", rather than a sine wave. Even the negative side is sort of a minus DC pulse, and not a curve. Well, I dont have this on "good authority", it's someones' opinion. I don't know as much about motors as this guy, so I'm inclined to believe him. If I have more time, I'll study the motor waveform with the o'scope.

So before we re-installed it, we tested it right in the bed of the truck on inspection speed, with 3 phase extension cables, resolver cable, and we had to jump out a bunch of stuff on the control. It ran on inspection speed, so we felt confident to rig it back into place.