Montgomery 6010 Comparator Board Tripping

Got a Montgomery relay logic 6010 tripping its comparator board. Any help is appreciated.

At what point in the travel are you tripping? If it is immediate it is prob a bad SCR or a bad SCR firing board. A bad 3ea board cand also do it. If it trips during accel or decel, it may be mis- adjustment of the Acel/Decl board. Also check out the Tach and wiring. These things are hard to trouble shoot without spare boards. You can check out the SCR's with a good multimeter.

Thanks JJ. It trips immediately. When I hold the P contactor in and run up on inspection from the MR the car runs down real slow. When I run down on inspection from the MR the car runs down pretty fast. I put a new tach on it and thought I found a smoking gun because the black wire stud on the tach was loose. The new tach did not fix the problem.

Can you explain to me how to test the SCR's with my meter?

Can anyone tell me the KONE part # for a 25HP 6010 AB drive SCR?

With a meter on ohms, or a continuity checker. Put the negative lead on the cathode of the SCR ( the large post ), and touch the positive lead to the anode (the base ), the meter should not read ohms or if using a checker, it shouldn't light. if it does it is bad. Now clip a jumper to the positive lead while holding it on the base and momentarily touch it to the gate of the SCR, it should read ohms and stay on, or it should light and stay lit using the checker.
You really cannot troubleshoot this controller by holding in the P switch. you can try briefly jumping out the comparator at terminals 5 and 6 on the 12ea board (comparator Bd.)
That may allow you to see something. Do not leave the comparator jumped out, this is just for testing purposes. It sounds like you have a bad board, maybe the 1ea or 2ea Op Amp board, or something like a six pulse firing board. Assuming you have checked the contacts on the P switch and the brushes on the motor commutator.

You should be able to buy the SCRs at a good electronic supply if you have the part number.

Thank you JJ

New SCR's, pulse board, and tach. Still tripping the comparator board instantly.

Yikes!, as I said these are hard to troubleshoot without spare boards. Just something to try, the 1 ea and 2ea are identical. switch them around and see if something changes. Also try disconnecting one lead of the motor armature, just to make sure it isn't grounded.

Those have got to be my least favorite beast to troubleshoot. As John said you really need to swap boards...I wish I knew how they did it back in the day
Seems like there would be an easier way.

Disconnected one motor lead and still trips. Swapped 1ea and 2ea and still trips. Is it possible that it could be a problem with the 1-4TR pneumatic relays?

Disconnected one motor lead and still trips. Swapped 1ea and 2ea and still trips. Is it possible that it could be a problem with the 1-4TR pneumatic relays?

So going back to your original post. Instead of holding the P switch, jump terminal 5 to 6 on the comparator board, this will let you run temporarily while testing. Be sure to remove the D010 wire so the doors can't open. You said the car runs down slowly, on up inspection. With a DCV meter + lead on Test point 3(wire 208) and - lead on TP 12(wire 121) you should have a positive voltage in the up direction. This is the tach circuit. It almost feels like you are missing a voltage or a contact somewhere in the circuit. Another check is at wire #187 TP-2 to wire #121 TP12. you should have, with the black lead on 121 a neg. in the up and a pos. in the down. TP-2 is fed with U and D contacts. Also, loose connections at terminal points will cause many hard-to-find problems. It would be wise to go over all connections. Good luck.

Replaced the 1EA and 2EA boards. The car is back in service. Thank you for the support. I think I'll need some hair implants. Lol