Home Forums General Discussion Technical Questions Dover T-IV VVVF Over Current.

Keep getting VVVF OC fault about 15 seconds after running on inspection in wither direction. Will not run on normal correctly.
sounds like its struggling to move but couldn't find any mechanical binds. This started immediately after repair team performed full load safety test. On normal it will run down slowly through the direction limit, onto final and shut down. Was trying to relearn terminal slowdowns and limits but after initializing it just runs down on final and thats it. Like I said...if it runs long enough it gives VVVF OC fault. Any ideas?

Never worked on 1 of these units. When was the last time your load weighing has been recalibrated?

Since you slammed the car on full loads I would check you vanes, vane clearance, the cam on the side of the car, and loose connections coming from the traveling cable. Also is BK3 picking. Those drive over current faults are misleading.

What faults are you getting on the IMS? What fault is displayed on the drive?

I doubt the load weighing is causing issues. On those units you can unplug the l/w ands see if it runs.

ha there is a moral to this story. If it aint broke don't fix it!!

Seriously did the repair crew change a parameter to try to get to run full speed/full load to test it? What is the fpm on the maintenance/full speed speed and is it the same for other lifts? Would the sudden stop, damage the drive scr's? It can be easy to replace the drive to prove it is ok?

I should add, check your dynamic braking resistor is in intact as well.

<-----this is good words of wisdom. Check bk3. Is the module getting up, check the coil