Home Forums General Discussion Technical Questions Tac50 53 and 908 fault

Been working on this tac for over a month. Keep getting a 53, open saftey string, then one second later a 908, basically etsd system micro controller is detecting overspeed. Doesn't do it every run but within ten-fifteen minutes it usually craps out. Found multiple issues that could have been causing problem. Counter weights were hitting buffers, gov tail sheave had trash in it, dirty p1 p2 connectors on pmi 1. Corrected those issues and changed modules, dsp board, gov encoder, motor encoder, multiple hoistway scans and back ups and still nothing. Today I found a bad/burnt resistor on ps2 and saw that is what feeds that system, ran the car and wiggled the resistor and boom car shut down exactly the same way it was! Repeated the procedure and it shut down again! Changed ps2 and started running it and within 15 mins shut down the same way again. Anyone had this before or something similar? Any input would be great Cuz I'm bout fed up with it

Is this the unit with the slowdowns that use perforated vanes? If so how is the alignment with a load in the car?

Yes it is, The vanes are dead nuts, went through and checked distances and gaps and corrected as needed

Understand your frustrations. I wonder, on the TAC 20, using IMS, there is a feature on a pull down menu in the diagnostic portion that'll let you run a variable time recording of all inputs and their states while running on automatic. I think it's simply called "Recorder". Once the car faults, you can go back and watch the "tape" to see which input may have blipped. Check it out. Also, there is a back up battery for the DSP. Typically right side near the bottom of the controller. Maybe not your trouble, but weak batteries in any control circuit can cause grief to the unsuspecting mechanic (KONE KMC, GEN2 and I'm sure there are more).

Ok I'll check out the recorder, it keeps shutting down at test point 5 and the demand just drops to zero. Lol and yes I did change the battery for the heck of it!