Pre-charge Fault

What does E.PCH mean?

This fault occurs during the pre-charge phase of the FR-A800 inverter, which is the initial charging of the DC bus capacitors through resistors to limit inrush current. A fault here indicates an issue with this circuit.

• Failure of the pre-charge resistors or contactor/relay in the pre-charge circuit.
• Issue with the DC bus voltage measurement circuit during pre-charge.
• Insufficient input power supply voltage, preventing the DC bus from charging adequately within the allowed time.
• Short circuit in the DC bus or output stage that prevents proper pre-charging.
• Internal control circuit malfunction related to the pre-charge sequence.

Click steps to track your progress.

1. 1

   Verify the incoming AC power supply voltage to the FR-A800 is stable and within the specified range.

2. 2

   Listen for the clicking sound of the pre-charge contactor or relay engaging after power-up. If it doesn't engage or stays engaged too long, it indicates a fault.

3. 3

   Allow sufficient time for the inverter to pre-charge. Repeated power cycling too quickly can sometimes cause this fault.

4. 4

   Check for any signs of damage or overheating on the pre-charge resistors or associated components if visible.

5. 5

   If the fault persists, it often indicates an internal hardware failure in the pre-charge circuit, requiring service.