Live zero error

What does ALARM 2 mean?

The signal on one of the analog inputs is less than 50% of the programmed minimum value. This condition, appearing if parameter 6-01 Live Zero Timeout Function is programmed, often indicates broken wiring or a faulty sensor/device sending the analog signal, risking incorrect operation or control.

• Broken wire or loose connection in the analog input signal path (e.g., between sensor and AI terminal 53).
• Sensor failure, providing an output signal below its specified live zero threshold (e.g., 4-20mA signal dropping below 2mA).
• Incorrect scaling of the analog input in parameter 6-10 (Low Reference) or 6-11 (High Reference), leading to misinterpretation of a low signal.
• External electrical noise interfering with the low-level analog signal, causing spurious readings.
• Faulty analog input module on the frequency converter's control board.

Click steps to track your progress.

1. 1

   Verify the analog input signal at the sensor output terminals using a multimeter (e.g., set to mA or VDC).

2. 2

   Measure the analog input signal directly at the frequency converter's input terminals (e.g., terminal 53 to 55) to confirm signal presence.

3. 3

   Inspect wiring for continuity and secure connections from the sensor to the frequency converter's analog input terminals.

4. 4

   Check parameter 6-01 (Live Zero Timeout Function) to ensure it is correctly configured for the sensor type and application.

5. 5

   Review parameter 6-10 (Low Reference) and 6-11 (High Reference) settings to accurately match the sensor's output range.

6. 6

   Replace the analog input sensor if its output consistently remains below the expected live zero despite proper wiring.