Hey jim, here is some ideas to pass on to your buddy, first, the crt1 and crt2 timer relays play an important part with the pattern input on take off. i would replace them both, you could check it out by giving more time on crt1 and 2, if you set them timers to a longer time, say around 2 seconds, the drive will pick the brake, and if the soft start pot on the drive is not set right, the car will drift up, with a light load, or down with a heavy load. have him check this first, set the timers for a couple seconds and run the car from the top floor, if the car drifts into the finals, adjust the soft start pot on the 6 CA board to hold the car until the timer picks up and applies the initial pattern input to the accel decel board.. this timer can also cause comparator trips if it is set to quick, if set to quick, the full running pattern will be applied before the brake picks causing a comparator fault. you check this on the 12EA board, there is a 1st and 2nd trip led on this board, if there is a big difference between pattern and tach the first led will come on, if it happens twice in a row the second led will light and drop the safe circuit. it is possible for just the first led to come on, the car will drop all relays and try again, if it makes it the second time then the counter is reset. maybe no one is reporting this at other floors, as they would probably just notice the car bump, and then take off. you said he replaced some relays, i would check the relays feeding the 7EA board which is the first board that the pattern goes to, they would be HS, 2LC, LR1, RR1, and the crt1 and crt2 timers i spoke of earlier. I would replace or check the RR!-RR3, RRA and the pneumatic timing relays 1TR-4TR, these are problematic. That would probably be it for the relay portion of the drive, it is possible that one of the boards could be acting up and not outputting. as a last resort go through and tighten all board connection screws. ps self-proclaimed, this is an old relay logic controller with 6010 scr drive, not the megatech,miprom 21 where you can log on and disable the doors, and set automatic calls to on , and check for motion and drive faults. this is old school, the only faults are the 2 led lights on the comparator board. should be a fun one to track down, good luck to your friend jim.
