Drives Service & Support > 1336F > Fault Finder

Fault Number: 15
Fault Display: Motor Thermistor
Fault Name: Motor Thermistor
Description: An analog option board with thermistor input is installed and the value at the terminals is less than 60 ohms or is greater than 3300 ohms.
Corrective Action: This fault will only occur when there is an LA6 card installed on the drive in Analog I/O Option Slot A. A motor thermistor needs to be hooked up to terminals 3 & 4 on the LA6 card. The motor thermistor needs to read between 60 and 3.3k ohms. Proper hookup is the (+) thermistor input should be on terminal 3, and (-) thermistor input should be on terminal 4.

If you have a motor thermistor hooked up, and you are getting this fault, either the motor is overheating, or the thermistor may have failed. Using an ohmmeter, disconnect the thermistor from the LA6 card, and take a reading. If it is outside of the 60 to 3300 ohm range, then the motor thermistor is faulty, or the motor is overheated. A check of the motor would be recommended for actual temperature of the motor.

If the thermistor reads within the 60 to 3300 ohm range, and the motor is not overheated, and the wiring is deemed accurate, then the LA6 card is most likely faulty. It is recommended that you replace the LA6 card, or swap in a known good LA6 card to see if the problem goes away. If the problem persists after a known good LA6 card is used, then the main control board should be replaced.