24 volt DC motor control.

[Gus the mechanic]

I’m working on a 33 year old material handling stacking Jack. It’s powered by a commercial 24 volt battery. It uses a dc system with a scr and 5 rectifiers that control three high current contactors to power a dc motor. It is ul rated at EX I’m trying to diagnose this unit’s inoperable it has a speed controller and two of the contactors controller B+ the third controls B-. I’m having a hard time understanding what the purpose of these rectifiers do. I appear2 they must cut the 24 volt supply down to lower voltages. it appears as though some of them are not putting out any voltage. Is there a way to test them? Any help would be greatly appreciated. Thanks.

 

[charlie b]

I am closing this thread in accordance with forum rules. We are not allowed to assist a person who is not an electrician to perform their own electrical work.