Home Forums General Discussion Technical Questions Otis Drawing 1-A257501C

Having an issue with this one that the door is not opening on auto for car calls. Opens on hall calls. Once stops at floor, if you press the door open button the doors open. I am struggling seeing the difference in a hall call and a car call to energize the DOL relays. NT is the hall timer, and it pulls in with a car call. NT stays energized on a hall call until the door opens up. On a car call it drops out once 1E drops. If we hold in NT the door open. Not sure if I am going in circles or on the wrong track...

Excellent description of the problem. This is a 10,21,30UCLS, NT should never immediately drop, its capacitive timed. Since you have no basic NT time, its likely you have an open capacitor “NT1”. We know the rest of the circuit is good because HS additional timing is working through the “NT” cap.

Thanks. We had tested those capacitors and they were good. Must be a bad connection in that circuit.