Was looking to see if anyone has had a similar experience on a old duplex traction job, 2c2bc erl controls.
we were replacing the 41B coil on the number 1 car, had the power off, and had to loosen the screw holding the ES relay, in order to get the coil in and out. While we were in the midst of replacing, building engineer came to machine room and indicated that the other car was running with the doors open. we immediately shut off the car, and i had the mechanic run down to make sure the doors were closed and we had control of car, he met 4 people in the stairway that were in the car when it ran with the doors open, very scary situation, after we made sure the car doors would not open we ran the car from the controller, and it ran fine, now we are a bit uneasy to say the least, we decided to get the coil replaced so we could have one car running in the building, while trying to get the coil in, we noticed that the direction relays 2A, and 2B would pick up in the other car that was on controller inspection at the time, they would chatter as i moved the 41b relay around. if 41B number 21 contact would touch the frame of the controller, the direction relays would pick in the other car, i could simulate the problem by just putting a jumper on 41b 21 contact to ground, and sure enough the direction relays would pick up in the other car, it did not matter if any of the door relays were out, or the 29 relay was out, i could physically hold 41,41a etc out and still would pick up direction relays. so now i decided to find out why, ended up finding the number 21 contact of LU relay in the contact holder incorrectly, causing it to be wedged up against the relay frame, repaired it, and now i could not get the direction relays to pick. I decided to see if i could simulate this exact situation with the other car, so i proceed to jump same to contacts to ground in opposite cars, and sure enough same outcome. This seems to be a design flaw, since 79 and 00 power supply is ungrounded, this double ground situation somehow found a path between the 2 controllers and cause this problem. strange thing is that the bigger relays, 2 and 6 did not pick up while i was testing this scenario, only 2a and 2b, using the meter, i found that there was only 48vdc across 2a, 2b, 2 and 6 relays with respect to 00, just enough to pick up the ES relays, but not enough to pick up the bigger 2 and 6 relays, however the car did run with both car and hall doors open, as we have 4 eyewitnesses. so i am thinking that while moving the 41b relay around, some of the other contacts must have introduced a little extra voltage to the scenario to pick up the relays 2, and 6 or the car stopped, and 2 and 6 dropped, but then 48vdc was applied, and that may have been enough to repick the relays. Has anyone experienced anything like this?
the 41 b contact that i grounded was in the 438 circuit, I know it seems like 1 in a million chance for this to happen again, but i was the 1, and it will happen elsewhere
just giving a heads up to be careful when working on these cars, or any system that has floating power supplies for the controller. If any one can give me any advice, please pm me, if you have ran across this situation. or something similar
