So I already searched the forums for someone who wants to modify their electric winch, and found one such topic, but mine is more straightforward. I have a Tiratutto HT125-200 electric hoist (230v @ 50 Hz). I am not interested in the hoist function, but wanted to re-purpose the motor to use to motorize a roll-off observatory roof (similar to this). So I removed the cable hoist and installed a spur gear on the motor shaft.

After inspection of the pendant switch and circuit diagram, it seems that controlling the unit using externals relays is straightforward:

Circuit Diagram:



Pendant Switch:



It appears that I would need 3 relays. One relay to control junction #1 in the diagram which would make the motor to UP or CW. And two relays for junctions #2 and #3 to be activated at the same time to make the motor go down or CCW. Planning to use a web controlled din relay to drive the motion. I'll also re-wire the limit switches to my external limit switches.

Is this all I need? Any simpler ideas? Anything to worry about?

 

Appears to be a 1ph induction motor, so you will need a method of reversing the split phase motor and also 2 limit SW each end for end of travel.
Max.

 

Yes it is a single phase induction motor. But the rocker switch already reverses the motion (UP and DOWN on the circuit diagram correspond to CW/CCW shaft motion).

The capacitor in the pendant switch is composed of two capacitors connected in parallel (12.5 and 3.5 microfarads) and it is the capacitor that enables the single phase power to turn the motor since it introduces a phase shift that is necessary to induce a rotating magnetic field and hence emf.

I already have 2 external limit switches that I'll wire in, but that is not my worry. If I introduce relays to this circuit as I described above, would this cause any issues?

 

It wont cause any issues, put the relay contacts in place of the UP /DN switch, and wire the coils in series with the limit switches, the relay will need to be 230V ac coils, and have two sets of change over contacts, one set can be used to latch the coil if needed.