Fault in QM DI main drive

Hi Guys

Please I need your urgent prescription to the problem below:

When I try to inch or run, the main drive does not turn after the safety warning sound. I eventually traced the fault to the drive brake. Apparently, the brake is not released when it should. If I apply the manual break release immediately after the safety warning sound, the machine runs and I can work until the machine stops.

How can get the break to release automatically again?

Thanks for your time.

 

Strange, do you keep manual break all the time the press is running, or is it enough to pres in at the moment of the start?
In the first case it could be power supply for the break (e.g. fuse on TTK), the second one would be very curious, I could imagine the dirt in the pull-push mechanism of the break, that make it working not steady.
rgds
Jan

 

Yes the manual brake is applied while the press is running. If we move our foot from the manual break, the press stops. We now run the press like a sewing machine!

I've checked the fuses on the TTK and they're okay.

 

It is the lack of the brake tension, or interruption in the brake's circuit , alternatively mechanical problem in the break
(electrically OK, but mechanically blocked).
rgds
Jan

 

There are usually 3 concealed fuses on the rear of each of the rectifier circuit boards, you can test them by buzzing across the print. One of these boards supplies power to the brake lift circuit, they are twin bridge rectifiers arranged as a 3-phase bridge and fed off one of the transformers.