Cause : Signal lost on analog input comes when the inverter has lost communication or received an invalid signal from an analog input channel.

Here's how to troubleshoot this issue:

1. Check Wiring Connections: Verify the wiring connections for the analog input channel. Ensure that the connections are secure, properly terminated, and connected to the correct terminals on both the inverter and the external sensor or control device.

2. Inspect Sensor or Transducer: If the analog input is connected to a sensor or transducer, inspect the sensor/transducer for any signs of damage or malfunction. Check for loose connections, broken wires, or faulty components that could be causing the signal loss.

3. Calibrate Sensor: If the analog input relies on a sensor or transducer, ensure that the sensor/transducer is calibrated correctly. Improper calibration can result in incorrect signal readings or signal loss. Follow the manufacturer's instructions for calibrating the sensor/transducer.

4. Verify Input Configuration: Check the inverter's parameter settings related to the analog input channel. Ensure that the input channel is configured correctly for the type of signal being received (e.g., voltage or current), and that the scaling and offset parameters are set appropriately.

5. Inspect Power Supply: Verify that the power supply to the external sensor or control device is stable and within the specified voltage range. Inadequate power supply voltage can cause signal instability or loss.

6. Check Grounding: Ensure that the inverter and all connected devices are properly grounded. Poor grounding can introduce noise or interference into the analog signal, leading to signal loss or instability.

7. Analog inputs are commonly used in inverters for various purposes such as speed control, current control, or parameter adjustment. 

• Broken wire.
• Signal out of limits.