Hi All,

We've just inherited some Tac50s. 3 in one building, and 2 next door.

The group of 3 have sheave brakes, and each one of these gets constant 224 errors. One car gets about two per week, and the others seem to last a bit longer.

I've gone through the mechanical set ups, as far as measurements, and clearances, and they seem good.

Ive increased the pick voltage time, increased the delay between the sbk pick, and the main brake pick, and increased the time that the sbk stays up to the maximum of 3600 (60 minutes) in hope of finding a sweet spot.

We haven't started swapping relays, but that's our next step, I have tested all of the contacts,mand they seem good. Most of the contacts have been doubled up with spares also.

After this I'm almost left with this being a design problem, but thought I'd ask here.

Incidentally, the 2 car group next door uses HW rope grippers, and do not have this problem.

What do you think?

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.

check the GTS module

224 is sheave brake switch, essentially the switch is bad, or the brake didn't pick.

I have not done any of the above, but will try it.

They are tac50, not -04

Thanks

Thanks, I will do that.

Check micro switches, for brake and sheave brake, they have come apart in the box they where mounted in and where hit or miss. Also there maybe a write up on that sheave brake the way they were wired up on older jobs due to brake burning up....

Did you ever find the problem? Do you get the fault on every run?

If not I bet its gotta be a contact on a relay.

I did go over the switches pretty good.

I actually saw one of the cars not pick the brake once. I believe it didn't get a good pick voltage, and have a new EBH relay on the way. Hopefully that is it.

I'm thinking about a way to integrate a Holister Whitney rope gripper into the system, and getting rid of the sheave brake. I think I could do it all with sbk, but the only problem I can think of is that it looks like I can only set up about 4 seconds delay from the time the time sbk picks, until the main brake picks, and I'm unsure that it would always be enough time for the gripper to pick. Also, when sbk dropped due to inactivity, the gripper would have to drop. I don't know that it's really designed to pump up over and over.

I wish the was a gripper/sheave brake option in the software, but don't see it.

Ive had at one time 36 Tac-50-04 and 22 Tac-50-03 with sheave brakes and never had a single problem with them. Besides normal relay and switch issues. I've never had to take care of any card racks with sheave brakes but the rope gripper on those seem to work out pretty well. RGC1 and RGC2 aux contacts needs to be chnaged every 6 months during my machine room maintenance. I've had seals blow out on the gripper itself. Some units leak and then when they get low theyll set the gripper. I perfer the sheave brake to gripper cause of no oil to deal with.