Applicable Systems
Okken
Symptoms
The TeSys T motor management controller reports motor over-temperature via the PT100 input. The controller trips the contactor and the MOTOR TEMP LED turns red. The motor surface is >75C.
Possible Causes
- Motor cooling fan blocked or damaged
- High ambient temperature in the PrismaSeT enclosure (>45C)
- Excessive starts per hour causing cumulative heating
- Incorrect PT100 threshold setting for the motor insulation class
Troubleshooting Steps
- Step 1: Inspect and clean the motor cooling fan and ventilation passages
Air flows freely and the fan runs smoothly without noise - Step 2: Measure the ambient temperature inside the PrismaSeT cabinet and verify enclosure ventilation
Cabinet temperature is <45C and vents are unobstructed - Step 3: Review the motor duty cycle and compare starts per hour against the nameplate
Start count is within the allowed duty cycle (typically 3-6 starts/hour) - Step 4: Verify the TeSys T temperature threshold is set 10-20C below the motor insulation class limit
Class F motor (155C) has alarm at 130C and trip at 140C
How to Reset
Allow the motor to cool for at least 20 minutes. Reset the TeSys T by pressing the reset button or via Modbus command. Re-energize the contactor after confirming the temperature is below the alarm threshold.
Common Replacement Parts
- LTMR08EFM: Schneider TeSys T motor management controller (Includes LTMR base unit and LTME expansion for PT100 input)
Frequently Asked Questions
- Q: What is the maximum cable length for PT100 to TeSys T?
Up to 100 m with shielded cable and 3-wire or 4-wire connection to compensate for lead resistance.
- Q: Can I use a thermistor instead of PT100 with TeSys T?
Yes. The LTME expansion supports both PT100/PT1000 RTDs and PTC thermistors. Configure the input type in the software.
Source: Schneider Electric PrismaSeT Technical Guide, GDE0001
Category: Electrical