Hi guys this is my first post and i was wondering if anyone could help me on a problem im having. I searched all related issues but i still cant get to the root of the problem. I have a miprom 21 traction with an otis ht131 traction machine and the car keeps crapping out on me when it goes to take off. Ive replaced the ets and nts boards, relays and the drive was rebuilt. If i lower the mvel down to 100 fpm the car runs on auto no problem. As soon as i bump the speed up to like 110 fpm ...... Faults out. I replaced the motor encoder as well. All velocities seem fine between the position encoder and motor encoder at 100 fpm. Im getting about 6.7vac ripple across a1 and a2 on the armature. Should i get a motor man here to megger the equipment? Any info would be much appreciated. Thanks

do you have a tool? what do you mean crapping out? does it just stop, and not recover? if you have a tool, what kind of error codes are you getting. why did you replace the ets nts boards? was ets and nts dropping out? how fast is the car?
have you checked the 150fpm, int , and hi speed, rl speed boards.

I have the tool. Car goes to take off and it faults out on motion fault *23 *13 and *38 and drive fault cp-18. It recovers and tries to take off again and repeats. I replaced the boards because it was on the terminal landing but it does the same thing throughout the hoistway. The car is 500fpm. I replaced the speed boards with a running car.

23 hard fault, what kind of drive, if a digital dc, did you check drive fault log to see what kind of fault? if its a analog dc drive, not sure about hard fault with that drive. does seem strange it will run at 100 fpm with no trouble.

Yeah hard fault 27 on the drive. Allen bradley 1395 drive series b. Cant wait for them to mod this place ....

under drive faults does it say cp or vp and then a number like cp27 vp 27

When you say the Drive was rebuilt, did that include the Main control board in the Drive? If so your parameters are at Default, and you may have to go through and put them back to what ever the original Field Adjustable Parameters were at the time of install.

Just saw post name. Cp18. Is that the drive fault

I have had a couple of these. One solution was the replacement of the feedback board on the drive. This board receives from the DC current sensor, AC Current, and field currents. On another car with the same problem I replaced the armature pulse transformer/snubber board behind the feedback board. There is a procedure on testing this board, I actually found a burnt resistor when I was testing it. You could be having issues with your SCRs. Make sure you tighten the thumb screws nice and snugg as they serve as ground. This problem drove me crazy for a while. Please keep us informed. I agree 100% with john jay, check and verify the parameters on the drive before anything.

I forgot to mention that I have series A Digital drives and you mentioned having series B.

Thanks guys. Yeah , its a drive fault. The drive was sent out to our tech guys in Texas and was tested before they shipped it out. Ill be going to this job tomorrow to see what else i can do. I checked all the parameters and wrote them down from a running car so im pretty sure the parameters are correct. Maybe ill just pull out the old sawzall lol. Ill keep tou guys posted!

So, if the parameters are correct, a CP18 indicates an Armature Current unbalanced. Make sure your incoming 3 Phase are balanced. If they are try increasing the K Discontinuous parameter in the Drive 10 or 20 percent. Also your Armature Current Bandwidth may be too low. you can try increasing the Bandwidth Parameter. Before doing any of this go through and double check all Drive and CPU Parameters. Also Drive parameters vary from Machine to Machine, so the Parameters from the Car next to you may not be correct. The Ohmic value of the Armature Windings Dictates the Bandwidth. Also check that the Field Parameters are correct. Too low of a Field Current will cause The Armature to throw a Fault.

Went over all the parameters and adjusted rl1-2-3 properly. Dropped the brake and serviced it. Replaced all the relays and secured all loose connections. I was able to get full speed runs with no load. As soon as I put it back in service it shutdown on take off when people got on..... I noticed the more i play around with the brake pick time i can get it to run again. Seems very sensitive. I have the brake pick set at .500 sec and car runs fine. When I drop it down to lets say .200 secs it shuts down. Should i just get weights here and adjust the brake pick with a full load? Thanks

Does this have the load cell on a disc brake mounted at endthrust bearing end of the machine?

Otis ht131 gearless machine. Car runs fine with no load. I put 2000 pounds this morning and nothing..... Drive faults out. I did notice that parameter 625(torque mode) is set to 0 while the other running car is set to 1. Where 0= zero torque command and 1= velocity reg. Output. I cant change it and im not sure if its adjustable. I also bypassed the choke as someone recommended from engineering with no positive results. Im waiting for the motor man to check the armature and fields out. Fingers crossed !

Well had the hoist motor checked out and everything checked out...... Going to send the drive out again. I put 500lbs in the car and the drive trips meanwhile if i put it on inspection it will go up no problem 😒.

have you checked field amperage in the parameters? are the voltage jumpers in the drive in the right place?

Scoped armature voltage ..... Shady readings . Sent drive back out to replace scrs and armature pulse boards. Its now running like a champ !

Nice..!!

If by Texas you mean ITS, I routinely have to send Miprom 21 drives back multiple times before the car will run.