That time I fought a governor rope adjustment for 3 hours

I had this Otis unit in a 12-story building near downtown Phoenix, kept getting a overspeed switch trip during an emergency stop test. Thought it was the governor spring tension or a bad switch, swapped those out first. Turned out the rope had stretched unevenly and was rubbing the sheave guard just enough to cause a false signal after a full load stop. I should have pulled out my tension gauge in the first 20 minutes, but no, I had to chase parts for 2 hours before I got real with myself. Has anyone else had a governor rope that measured fine at rest but shifted under load?

3 comments

3 Comments

sean_murray16d ago

Yeah and that's the worst kind of gremlin right there.

evan15116d ago

Can't believe @margaret_bennett3 caught that on video, wild.

-1

margaret_bennett316d ago

The trick that saved me was doing a loaded drop test with a GoPro taped to the sheave guard. Watched the rope walk about a quarter inch sideways during the stop then settle back at rest. Ended up slacking the governor rope off completely, cleaning the grooves on the sheave, then retensioning with a digital gauge while the car was at mid travel with a half load in it. Hasnt thrown a code since.