Some notes, 3 turn pulley system we call 5:1 roping, and is a ridiculously inefficient system, I’ve never seen or heard of that being used. 2 turn systems we call 3:1, and is used in rare applications. We also use 2:1 quite often, which is still a 1 turn pulley system at the top, but on the car it loops to a fixed point at the top. 1:1 is what is used the most as it efficient i when conjoined with a counterweight. We don’t ever use different roping systems for the counterweight and the car, it’s always the same roping style.
In my 40 years in the elevator industry, I never came across any elevators where the elevator and counterweight used different roping configerations. 2:1 configurations are not uncommon, mainly confined to lower buildings, and I had a building on my route with 4 freights that had 3:1 roping, but of course in all instances the car and counterweight roping configurations were the same.
@@tbbelevators3181 No, I never did. The 3:1 at what used to be the main Vancouver Post Office building, was the most I ever came across. Must be fun to replace the cables on a 5:1. Was bad enough on the 3:1
Thank you for video my question how I can calculate the distance and the power that need to left 2 ton up ,,if you can help me if u have formula or Equation thank you
One horspower equals 33 000 foot pounds per minute, i. e., what it takes to lift a weight of 33 000 lbs a distance of one foot in one minute (or a weight of one pound 33 000 ft. in one minute). In your case, 4000 lbs. (one ton) /33000 = .1212 (or about 1/8) hp. If you want to lift it higher, or faster, or both, you'd have to increase the horsepower proportionally. Of course that doesn't take friction into account, and that would be stretching the motor's capacity to the ultimate, but it would give you a starting point.