12 pulse mce drive gives intermittent motor field failures. replaced alot of hardware per mce tech support. noticed that failure will occur when going from independant to automatic. switch back to independant and runs ok. first switch to auto and either very rough accel( no error logs ) or "motor field failure". problem began after building power surge. any suggestions?

-- cliff (cliffchiyo@verizon.net), December 30, 2004

Answers

Check your prints and see what input that initializes independant service and which one initalizes automatic. It's been a while since i've had to deal with MCE, but what your describing may be a contact on a relay or something to do with the door close circuit. On independant you have to hold the door close button. You may want to go through those circuits also. The power surge may be a coincedance.

-- Bill (elevatorman_1@msn.com), December 30, 2004.

response

Your independent service just turns on a flag in the computer,i think what is happening is that on independent service the fields are held at standing voltage,until you are ready to run,but in auto if the car is given a call the fields are built up to forcing until the doors close and car takes off,maybe the motor fields are breaking down after being held at forcing so long

-- Eric Appana (aappanajr@aol.com), December 30, 2004.

Good answer, but why would you want to hold the fields at full voltage on independant service ? What are the reasons ?

Isn't there a pre torque setting ? And isn't it run by a switch in the door operator ?

-- Bill (elevatorman_1@msn.com), December 30, 2004.

independant and auto are only inputs to the swing panel, and the fields are held at standing until the run enable signal given after doors are closed (on either ind or auto). the dpp board in the swing panel is dedicated to motor control only and should not be affected by the type of operation. appreciate the comments, keep them coming

-- cliff (cliff77@att.net), December 31, 2004.

Try changing the ee prom on dpp board reload all prams and learn limits. If the chip is 2816 xicor. I have seen the checksum change putting cars into diff. failures.

-- kram (manwick@comcast.net), December 31, 2004.

good thought, i replaced the dpp but used the original eeprom. mce claims my software cannot fail intermittently. i did reload old eeprom and run new tables. i'll try the new one

-- cliff (cliffchiyo@verizon.net), December 31, 2004.

how old is your MCE controller ?? the drive turn on any fault led.. or this foult is in the error log ??

-- !@#%%^ (elevatorpr2000@yahoo.com), December 31, 2004.

See guys, this is what i love about MCE... the old fashioned " hunt and peck " method of troubleshooting. I will almost bet that his door operator isn't adjusted right, and on independant service while he is holding the door close button the door is getting shut. On automatic, it's relaxing and he is rolling the door lock.

The problem is gonna be something stupid like that. There is no reason at all why independant and automatic accelerations should differ. The drive doesn't care.

-- Bill (elevatorman_1@msn.com), December 31, 2004.

the locks are ok, pulled the feed and got the dlk error. this is a 97 job. the recorded error is motor field failure, the flag is the same. this car is in a triplex that has run well for the three years i've been there. ever since the power issue the other cars have had problems which new hardware seems to have corrected. this car is the last one with problems. a new das corrected a decaying field problem, the new dpp took away a tach error but left the field failure. all hardware new. i'm stumped by the independant auto thing, makes no sense. just noticed this yesterday

-- cliff (cliffchiyo@verizon.net), December 31, 2004.

try to delay the speed pick delay "TSPD" just to see any difrent THE tspd could delay the run and recive time to charge the field OR remove the harware frome a car is running well and istall in this car maybe you recive a bad board !!!!!!!

-- !@#%%^ (elevatorpr2000@yahoo.com), January 02, 2005.

Why trust the fault log? Monitor the fields independently and see exactly what is really happening... Then work backwards. Think 1980's.

-- Hat (slideheadfirst@cox.net), January 10, 2005.

thanks to those who responded, we've masked the problem with adjustments. mce cannot explain the error, software should not have any relationship with drive mode,or so i've been told. my problem may have just been reduced to an intermittent, time will tell.

-- cliff (cliffchiyo@verizon.net), January 10, 2005.

independent or automatic operation should not have anything to do with motor field. forcing motor field voltage occurs during the door close operation in either case. it seems like you have invested a lot of time and resources already into this problem. have you checked your basics. all motor field connections are proper and tight. the wiring is in good shape with no potential grounds. the field windings are in good shape and clean. the motor field voltage has been properly calibrated. the ac input has not changed and complies with print specifications.

-- big joe (jospro@msn.com), February 12, 2005.