System failure

What does CCr mean?

This fault indicates a system failure caused by strong interference injection on the control cables or ground/earth loops in the wiring. Such interference can lead to unpredictable system behavior and instability.

• Inadequate shielding or incorrect grounding of control cables near high-power switching devices (e.g., motor contactors, VFD output cables).
• Existence of unintended ground loops due to multiple grounding points for the same circuit, causing circulating currents.
• Nearby induction motors or welding equipment generating strong electromagnetic fields without proper spatial separation or EMI filters.
• Faulty or undersized earth ground connection for the control cabinet, leading to poor dissipation of fault currents and noise.
• Supply voltage transients or surges exceeding the controller's specified immunity levels, often from switching inductive loads.

Click steps to track your progress.

1. 1

   Verify the integrity and connection of all control cable shields to a single, proper ground point within the cabinet.

2. 2

   Use a multimeter to check for continuity between the cabinet ground busbar and the main incoming protective earth (PE) connection.

3. 3

   Temporarily disconnect non-essential external wiring (e.g., analog inputs, digital outputs) to isolate the source of interference.

4. 4

   Install common-mode choke filters on affected control signal lines or line filters on the incoming power supply.

5. 5

   Measure the voltage potential between different grounding points in the system to identify ground loops (ideally 0V).

6. 6

   Relocate sensitive control cables away from power cables (minimum 30cm separation) or use shielded conduits.