Miprom21 41 error

Intermittently getting this error. 200fpm car. Runs fine for days then craps out. The position encoder has been changed, the low speed and intermediate speed boards were swapped and adjusted for proper setting. Motion info shows only a couple of fpm deviation from target. U38 and U39 on the relay pilot board were swapped around. Relays on the ETS board and the board itself have been changed. Looking for some input on the possible culprit. The MSU is getting changed this afternoon.

Does this car use a cartop encoder? If so make sure BJ1 on the relay pilot board is in the 1-2 position, and the nc contact on rr relay is good. This error can sometimes be caused by a loose ground wire in the cartop position encoder or the +12vdc to the position encoder being flaky. Are you getting the+12vdc from the controller? If so check that it is stable. I think I had this problem once and it was the +12vdc dropping from the controller to the cartop. If I remember correctly I used the 12vdc from the Zap unit to power the position encoder. Not sure about this, it has been a while. Something for you to look at. For sure check grounding and shielding ground from the position encoder.

Well I got rerouted so I'm not sure what they're doing as far as the MSU. This has the governor mounted encoder. One of the techs there told me it is only doing this in the down direction from what he has seen. I have walked them through how to look at Motion Info and Motion Averages and see what is being read. They're saying the numbers are only a couple of fpm from the target with some flucuation. I will probably get to look at it sometime next week.

only in one direction indicates a broken encoder coupling.

I was thinking the same thing John, but he states the encoder was replaced. I’d think he’d caught that, but....
If anything a loose set screw on the governor side mounting pin? But if he uses the speed boards, then those bifurcated relays used can be flakey too as they are directional I think.

I still have yet to get there. This one may have to wait because I'm on vacation for 10 days starting Thursday. The route tech has been on the phone with me but he's getting frustrated. The relays on the ETS have been changed. The drive has been "upgraded" to the DSD 412 from kone. From what they're telling me it only happens in the down direction. The Ven and Vfb are within a couple of fpm from the command. The speed boards trigger within a couple of fpm of the target, 152 and 185 if I recall correctly. They have bumped up the inspection speed to 100 fpm and motion info screen three, Vcmd, Ven and Vfb are good at 100 fpm up and down. If he has time I will tell him to check the encoder mounting shaft on the governor, he says the set screws on the coupling are tight and it's intact.

I guess you should start looking at encoder wiring for loose connections and possibly replacing the relay pilot board. Also, check that the governor rope tension sheave in the pit area, it may not be putting tension on the rope.

Bad encoder out of the box?

Is it one of the old 5 Volt encoders or a 12 volt.?

I ended up replacing the guide inserts and shimming a floor vane. There was so much slop in the system that the car was actually getting lost and for some reason registered a 41 error. It's been running ever since.