Hoist brake solenoid buzzes/fluckers instead of steadily pulling

Ignoramus22978 · 2011-11-13T14:00:33+00:00

I have a 3 phase Yale 1/2 ton hoist. It has an electric brake with asolenoid, whose job is to pull away the brake lever when 230VAC issupplied to it.The problem is that it does not do it. Instead of steadily pullingaway, it constantly jerks the lever, but never far enough to the endpoint where it is supposed to be pulled away. So, the brake is notdisengaged as the hoist operates. I am glad that I noticed that. I tried pulling on the lever by hand when the solenoid was engaged. Inoticed that if I help the solenoid and pull away the lever to theend, jerking stops completely, but if I slowly let go of the lever andit returns to the brake position, jerking resumes. I am thinking that perhaps this solenoid has two separate coils,pulling and holding one, and the holding one is not working or notengaging?Any idea?thanks