Analog Input Loss

What does F29 mean?

This fault occurs when the drive detects a loss of the analog input signal, specifically when the input falls below 1V (for 0-10V input) or 2mA (for 4-20mA input). The signal loss event clears when the input rises above 1.5V or 3mA. This usually indicates an issue with the wiring to the analog input, a failure of the external sensor, or the analog signal source itself. If unresolved, the drive's speed reference may become erratic or stop, impacting process control.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Measure the analog signal directly at the drive's input terminals to confirm it is present and above the specified recovery thresholds (1.5V or 3mA).

2. 4

   If using 0-10V input and the fault occurs at zero speed reference, ensure A110 [Anlg In 0-10V Lo] is set to a minimum of 20% (e.g., 2 volts) to avoid false fault triggers for zero reference.

3. 5

   Check A122 [Analog In Loss] setting to ensure the 'Fault (F29)' option is desired for the application.