Rollup Door 12 VDC motor and controls

[FatherWes]

I picked up what I believe is a driver for an overhead door. It consists of a gear assembly with a steel detachable chain sprocket, a 12 VDC motor (Nameplate says MBJ 4201), and an arrangement of 4 relays or solenoids. I suspect it may have operated from a single interrupt type button and limit switches for full open and closed, but I am guessing on this.

I've included a couple pictures and a hand sketched wiring diagram. Is anyone familiar with this device, or this control system? All of the solenoids respond except for the one I've labeled S4. I have not check if the solenoids are NC or NO. The motor shows no sign of working, but it looks like the commutator was recently machined.

Given I'm not sure if I understand the control system in the first place, and the motor doesn't seem to respond to input and Solenoid 4 seems to be dead, I'm struggling to gain that understanding.

It looks like the terminals I've highlighted with an "?" are the only external connections. I'm thinking that the motor and solenoid chassis are grounded, but again, that's an assumption. I would like to know where to connect the battery and control inputs, and understand exactly how this thing works.

Any/All input will be much appreciated.

Wes

 

[Former Member]

Wiring diagram is wrong, as S4 and S1 can not be energized. Based on that I think there may be a few more errors.

I'm sure you checked but I somewhere a faulty idea slipped in.

 

[FatherWes]

Thanks! I've been scratching my head, struggling with that exact point. I cannot figure out why the control terminals for S1 and S4 are linked together, but the the electrical connection is secured and look like they've been wired that way forever. As is, it just makes no sense to me, and I very much appreciate hearing it's not just me who's confused.

Think I'll play with the motor to see if I can get it spinning. If the motor is toast, it really isn't worth messing with (I have no actual use for this - it just seems like too useful a thing to throw away !)

At least one of the solenoids is toast (S4), and two of the others are suspect (they close, but show pretty high resistance). Likely a lost cause from an electrical perspective. I can't help but think that somewhere someone has an overhead door that uses this setup and could use the gear assembly...