An AP1 AI1 4-20 mA loss warning on a Schneider drive indicates a problem with the signal on Analog Input 1 (AI1).

The "AP1" "AI1 4-20 mA loss" warning" on a Schneider ATV950 drive indicates that the analog input AI1 is not receiving a valid 4-20 mA signal. This warning typically points to issues with the current loop, such as a disconnected sensor, broken wire, or a malfunctioning signal source.

Steps to Troubleshoot and Resolve "AP1 AI1 4-20 mA Loss Warning":

1. Verify Signal Source:

   • Check the device that is supposed to provide the 4-20 mA signal to AI1. Use a multimeter to verify if the output signal is within the 4-20 mA range.

2. Inspect Wiring:

   • Examine all wiring and connections between the signal source and the AI1 input on the drive. Look for loose, broken, or damaged wires. Ensure all connections are securely tightened and there is good contact at all terminals.

3. Measure Current:

   • Use a multimeter to measure the current at the AI1 input. Verify that it falls within the 4-20 mA range. If the current is outside this range, it will trigger the warning.
   • Check for continuity in the current loop.

4. Check Parameter Settings:

   • Verify that the AI1 input is configured correctly in the drive parameters. Ensure that AI1 is set up to receive a 4-20 mA signal.
   • Review and adjust parameters related to AI1, such as input scaling, signal range, and any fault detection settings associated with AI1.