Inovance Drive Err45 Motor Overtemperature Error

Getting the Err45 code on your Inovance VFD? Learn how to troubleshoot motor overtemperature, check sensor wiring, and adjust carrier frequency to protect your motor.

In any industrial setup, the motor is the heart of the operation. To protect this heart, Inovance Variable Frequency Drives (VFDs) are equipped with a thermal monitoring system. If your drive trips and displays Err45, it means the motor’s temperature has exceeded the safe limit, or the drive has lost track of the sensor signal.

Err45 is a critical protective stop. Operating a motor at excessive temperatures can melt winding insulation, leading to permanent failure. Here is a human-made guide to help you identify if you have a genuine heat problem or just a wiring glitch.

What Triggers the Err45 Fault?

Unlike internal drive faults, Err45 usually relies on a physical temperature sensor (like a PTC thermistor or a PT100/PT1000) embedded in the motor windings. The drive monitors the resistance of this sensor. If the resistance suggests the motor is too hot—or if the circuit is broken—the drive trips.

Common Causes and Solutions

1. Loose or Damaged Sensor Wiring

Before you assume the motor is burning up, check the "nerves" of the system. In many cases, the motor is cool, but the drive thinks it’s hot because it lost the signal.

• The Symptom: Err45 occurs even when the motor is cold to the touch or immediately upon powering up.
• The Fix:
  • Inspect the signal cable running from the motor to the drive’s control terminals (usually the AI or specialized Temp input).
  • Ensure the screws are tight. Vibration can often wiggle these tiny wires loose.
  • Check for nicks or breaks in the cable. If the wire is cut, the drive sees "infinite resistance" and assumes the motor is extremely hot.

2. High Motor Temperature (Actual Overheating)

If the wiring is solid, the motor is likely struggling with heat. This happens when the heat generated by electricity exceeds the motor's ability to cool itself.

• The Symptom: Err45 triggers after the motor has been running for a while under heavy load.
• The Fix: Lower the Carrier Frequency.
  High carrier frequencies (the speed at which the drive switches its transistors) make the motor run quieter but generate more "harmonics" and heat in the windings. Try reducing the carrier frequency parameter (typically in the F0 group) to see if the temperature stabilizes.
• Check the Cooling System: Ensure the motor's internal or external fan is spinning correctly and that the cooling fins are not clogged with dust, lint, or oil.

3. Mechanical Overload

If the motor is being asked to do more work than it was designed for, it will naturally run hot.

• The Fix: Check for mechanical jams, seized bearings, or an undersized motor for the application. Monitor the output current—if it’s consistently at or above the nameplate Amps, the motor will eventually trip on Err45.

Step-by-Step Troubleshooting Checklist

Step	Action	Expected Result
1	Physical Touch Test	Is the motor housing actually hot? (Be careful!)
2	Check Terminals	Verify AI/DI and COM connections for the sensor.
3	Measure Resistance	Use a multimeter to check the sensor ohms at the drive end.
4	Adjust Parameters	Decrease Carrier Frequency (F0-15 or similar).

How to Reset the Error

1. If the motor is actually hot, you must wait. Thermal sensors take time to cool down and return to a normal resistance range. Trying to reset immediately will usually fail.
2. Once the motor is cool and wiring is verified, press the [STOP/RESET] button on the Inovance keypad.
3. If you need to get the machine running and suspect a sensor failure, verify the Group F6 (Input/Output) or Group H0 settings to ensure the correct sensor type (PTC vs. PT100) is selected.

Summary Advice

Err45 is your motor’s "fever" warning. Don't ignore it by simply disabling the protection in the parameters. If you have verified the wiring and the motor is still overheating, consider adding an external auxiliary cooling fan or upgrading to a motor with a higher insulation class.