Home Forums General Discussion Technical Questions Tac20 Fault 1027

3-stop hydro faulting out on a 1027. Door zone monitoring error.
Comes up as “selector” in IMS.

I have replaced DZ1, and DZ2 relays. Made sure all the relays are making connection because it’s easy to not have them seated correctly, stupid design. I have checked for missing magnets and or debris in the selector, selector tape is clean. I have the prints and I have replaced additional relays that affect this circuit as well to play it safe. Unit will run for about 15 min and faults out. I hope im going down the correct rabbit hole as I’ve heard horror stories of tac20’s throwing incorrect faults. Im a bit lost on this one. It’s been down for almost a week and really seeking some guidance.

Any information would be helpful, thank you

Check your 24v at DZ1 and DZ2 in the controller. There’s a lot of voltage drop possible in that circuit. You want to adjust the power supply so you have at least 23.5 there. If that voltage is much lower than P24 you could be loosing voltage through the DZE relay on the 188E, either contacts or pins in the relay base. This is one of the places Schrack relays in blue bases can be a real problem. If DZ1 differs much from DZ2 you could have a bad travel cable wires on one of the 2. If it’s happening that often you should be able to see one of the 2 IOs not coming in with the other or with a meter on DZ1 and another on DZ2. And of course it could be the main sensor card.

Thank you for the reply,

I checked voltage on DZ1 (24.2) and DZ2, (23.8) I also replaced all the schrack relays with Finders, noticed immediately they seat better. Checked all the blue diodes as well. watching the I/Os when the car is at a floor DZ1 and DZ2 are pulled in, when it leaves the floor they drop out and DZ1M and DZ2M pull in. According to the prints if I am understanding them correctly all my inputs and outputs are working in the correct order and when I find the car down faulted out I’m not discovering anything out of place. I performed a learn run for giggles. I will not rule out a bad travel cable completely but I find the unit in different positions in the Hoistway when it’s faulted. Where is the main sensor card? Are you describing the selector card in the Hoistway? Do you believe that the blue relay base itself could be bad. I’m missing something and I can not seem to find it.