Operator Connection Error

What does E40 mean?

This fault occurs when the communication between the inverter and its operator keypad (either integrated or external) fails. This interruption in communication prevents control and monitoring functions, causing the inverter to trip and display this error code.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Power cycle the inverter and the operator keypad to attempt to re-establish communication.

2. 4

   If the error persists with a known good keypad and cable, the inverter's control circuit board or the keypad itself may be faulty and require service.

3. 5

   Ensure there are no strong EMI sources near the communication cable or inverter that could interfere with communication.