They are TAC-50s not TAC-50-04s right? I know on the rope gripper circuits on those cars RGC1 and RGC2 relays the n/c can cause issues with the rope gripper setting intermittently but Ive never seen a sheave brake on a tac-50.Have you swapped modules and check the connections on the PMI boards and reseated the boards. That wont fix your problem but since you just took over the job its not a bad idea to go thru all that. I cant remember off hand but I think 224 is unattended motion. Make sure your coupling on your encoder is tight.
