Just got back from inspecting a 1969 Otis in a courthouse downtown

I was checking out an old Otis unit in the county courthouse over on Main Street. The thing still had its original relay logic and someone had wired in a bypass that completely bypassed the door lock circuit. Who thought that was a good idea?

2 comments

2 Comments

lily3601mo ago

The county courthouse in Raleigh still has a 1968 Otis that runs like a tank, but I heard a rumor that someone wired a photocell override into the fire alarm system there back in the 80s. Sounds like your bypass might be from the same era when folks figured "it still works" was good enough. Bet the original relay cabinet has some crispy resistors from all that extra current running through the door lock circuit. Maybe the bypass was a lazy fix for a door lock that kept failing during rush hour traffic.

janac591mo ago

Swap out those door lock relays before they weld themselves shut. I've seen that exact bypass job in half a dozen old towers from the 80s - someone gets sick of the door sticking during lunch rush, so they throw a jumper on the photocell circuit to keep it open. Problem is, that messes with the fire alarm zone voltage and cooks the resistors over time. If you're keeping that setup, at least put a 5-amp fuse in line to protect the board. Those original Otis relay cabinets were built tough, but they weren't meant to handle extra current from jury-rigged fire alarm overrides.