Otis 506SLgreenspun.com : LUSENET : Elevator Problem Discussion : One Thread
just took over a service contract that we know nothing about the equipment. sound familiar. don't even know if the prints i have are exactly for this esc. but anyway, it's an otis 506 SL, german production i guess, has the 2 removeable controllers in the upper end, 1 has relays and the mother board, the other 1 has "u" & "d" relays, overloads, transformers, ect. it has a socket for a inspection run box which ofcourse i don't have. the problem is the machine brake does'nt pick. its a 120vac solenoid and i do have voltage going to it so of course i replaced the solenoid but still have no brake. obviously it's been stopping by gravity for god knows how long. the j-box mounted on top of the machine brake solenoid also has a bridge rectifier? and a varistor wired in. i ain't even showing that on the prints i have. don't know if it was an add-on or what it's even doing there. i even replaced them. does anybody have a clue???????
-- Paul S. (escalator @ earthlink.net), March 22, 2002
Firstly....brakes on all type of equipment should b fail safe ....as in they need power to lift...therefore no power no lift...there should also b a spring to hold the brake on tight so the escalator wont move...not gravity. If u have 120 ac to the coil and its not picken upp did u check the negative side..it sounds like u dont have the neutral.....if there is a rectifier accross the coil its dc and u may have a problem there......i hope it helps but either way write back mate...ta
-- phil (firstname.lastname@example.org), March 25, 2002.
thanks for you're reply phil,not to argue you're point, everything you said is true but un-fortunately not in this case. whatever company serviced the esc before i received it had the brake rigged so the shoes wouldn't rub the drum. by gravity, i mean the esc just glided to a stop with no help. about a 4 step glide! neither the machine brake solenoid or the emergency brake solenoid were working. the e-brake to was rigged up. the machine brake solenoid is 120vac and my original question was what is a bridge rectifier doing wired into it cause it is a 120vac solenoid not dc.aparrently otis germany wired this rectifier(or whatever it is)& varistor into cause in europe its 50hertz and here in the great U.S. it's 60 hertz. maybe it changed the wave, i don't know, just a theory. but anyway, the new solenoids i received today have the necessary componets built in and all it took was hooking up the 120 volt wires & the solenoid wires and everything is working the way its suppose too!. thanks again. do appreciate you're reply.
-- Paul S (email@example.com), March 27, 2002.
always like hearing back about my replies so thanks for writting back....i learnt sumthing too...so its even better. c yah mate
-- phil (firstname.lastname@example.org), April 01, 2002.
The input to that brake is 120 volts ac the new brake solonoid comes with the rectifyer and varistor. If your brake was not picking prior what has happened is your shoes are gone will have to reline or buy new. we bought a new set and just get them relined locally to have around. The soliniod and shoes we got from Unitech expensive. But cheaper than a law suit.
-- crr (email@example.com), October 01, 2002.