Internal Safety Circuit Fault (CPU)

What does E.CPU mean?

This fault code signifies a detected malfunction within the inverter's internal safety circuit, specifically indicating an issue related to the CPU's safety monitoring functions. When triggered, it causes the inverter to shut off its output to maintain a safe state and prevent motor operation.

• Corrupted safety application firmware running on the CPU, causing integrity check failures.
• Transient voltage spike or power supply ripple affecting the CPU's internal safety core.
• Watchdog timer circuit failure on the main control board, failing to reset the CPU during an internal hang.
• Degradation of the CPU's internal safety logic or memory due to aging or excessive temperature cycling.

Click steps to track your progress.

1. 1

   Document the fault occurrence time and any associated external events (e.g., power fluctuations).

2. 2

   Execute a full power cycle of the inverter, ensuring DC bus capacitors are fully discharged (LED OFF).

3. 3

   Check the inverter's ambient temperature and fan operation, ensuring it's within specified limits (e.g., 0-50°C).

4. 4

   Attempt a firmware re-flash or update using the manufacturer's specified programming tool (e.g., FR-Configurator2).

5. 5

   If the fault persists, arrange for control board replacement as internal CPU failure is indicated.