I would hazard a guess that two is for the motor and three is for the pot.
Sounds like the pot was fed from 0 to +5 and the slider went to some kind of logic sensor input?
Max.

+1

Or hall effect sensor.

 

It is a sealed unit, so I'm not sure that opening it up would be wise? The only wires coming out are the 5, two for the motor and 3 for the feedback sensor.

 

If 5A contacts are enough.

Use two of these.
http://www.ebay.com/itm/DC-12V-H3Y-...467?pt=LH_DefaultDomain_0&hash=item20ea26fa53

Also need 2H timer of course.
If this is OK, I'll look for higher current version.

 

I will give it a try, thank you!

 

+1

Or hall effect sensor.

I just went by the ebay reference the OP posted, they all mention a pot.
Max.

 

Thinking out loud. 8-pin microcontroller. Two analog inputs and one digital output. Current sense resistor in the negative side of the motor supply to determine that the drive has reached a limit and killed power. Internal position pot wiper to indicate which limit was reached. Output drives a DPDT relay to switch directional power. Internal microcontroller timer to determine the 2 hour period end. Can also move the actuator to a desired position at the end of the 2 hours.

Still wondering about running this type of actuator is capable of running continuously for 2 hours.

Ken

 

Have you tried recycling actuator with 2P2T SW? might see what temperature rise is. What speed do you really need, might reduce V for continuous operation if necessary. Finally: Outline for operation with IC,s. Startup is delayed for .5 sec each time limit is hit. A,B,C, & D are Comparators; SR-FF= set, reset flipflop; H Br = H bridge or relay; current sense diode = shottky for rated motor current.
A time delay relay can be used, or a 4060 IC oscillator/ counter can be used, use 3 input AND for E or F & actuator will complete a cycle before stopping.