Having issues with a 7 stop Miprom traction. I believe it is called a 6010: large board with a bunch of ice cubes, about 12 drive boards on one door and several card racks on the other door.

Three cars in the hotel, one is out for mod; the remaining two cars are getting a workout. I also only have about four good print pages, no nomenclature.

The hotel is not on my route, but this is the second weekend in a row I have taken a call on the same unit. The car has shut down at the top floor as well as the bottom floor. Last weekend the issue was a tripped overload that was physically difficult to reset. Also, pretty warm in the machine room.

Today I had two fault lights on one of the upper boards. I tried using the reset switch, 1M pulled in and fell out; one fault light came on. 1M pulled in and fell out, second fault light came on and that was it, dead car.

I am wondering if excessive heat in the machine room can cause my problem? Anyone familiar with logic of the order of operation on this controller? I am not sure what makes the fault lights come on, I couldn't find anything obvious (hung relays, bad aux contacts etc.)

After stroking the mainline, the car ran fine while I was there. I put a couple of fans in front of the controller and transformer cabinet.

the the 2 fault lights are on the comparator board.A comparator trip occurs when the error voltage exceeds 40 millivolts when the unit is running. it can be caused by many things including tripping a door lock in high speed, losing the safety circuit in high speed,and other internal problems in the op-amp,pulse firing, field firing,SCR's and many other things. you reset it by toggling the switch on the board, if it trips with out trying to run, you may have a problem in the Field 3ea,or op-amp 1ea-2ea boards. Or the Comparator itself could be out of adjustment. Connect a DC meter black lead to the common terminal and red to the trip point terminal. You should have 4 vdc. you can cheat it up a little if you are getting nuisance trips. then connect the red lead to common and black to trip terminal, you should have -4vdc. The op-amp, and 3ea boards are plug and play. If you have spares you might try those. The heat would have to be up over 105f or more to cause a trip, but I wouldn't rule it out.Good Luck.

if 1m is coming in, make sure the brake is picking, if the brake does not pick the error voltage will exceed 40 millivolts and trip the comparator. thats where i would start. if the brake is picking, then it could be many things, like john has noted. good luck i have a couple manuals if you need i could send them to you the brake not picking is usually the issue i have found when it is intermittent.

Brake did not pick either time the car attempted to run. MR temperature was at least 85 degrees on both occasions, temperature inside the controller very well could have been over 100 degrees. Thanks for all the info, I will pass it along to the service mechanic. I'm glad that this equipment is being modernized.