good day all.

I am working on a Tms 200 with a tac5 drive.

The elevator overspeeding I adjusted the pot on the drive board which controls the speed but it didn't make a difference, I had also replace the board and its the samething.The motor carries a tachometer on it which normal gives 70volts dc ,when I read it it was giving 84volts,is it because the lift overspeed why the tach giving a higher voltage or is it because the tacho faulty

Check the position of jumpers x2 x3 on the new board

Then change the Tacho and the belt

The jumpers on the new board is the same as the old I also interchange the tacho with a lift that is working,same thing happens

the lift gets the slow speed but the slow speed seems to be to fast too

I don't know this equipment but i'm assuming its a dc drive type? Your wondering if the tacho is giving an incorrect error feedback? One way to test this is either swap tacho's, get someone to drive the lift on inspection and test the tacho output and then test this against another lift. Also you can test the volts/amps at the machine and then verify this with another lift. Most dc high speed lifts overspeed purely because of an over current situation either directly via the dc drive or because they are told to by the encoder/tacho or a friction issue.

ok thanks,what I found was the thyristor for the slow speed in the drive got bad so its slowing down now,but the governor keep tripping when it runs on high speed