Issue:
What are the different operation modes of PowerLogic A3 and when should each be used?
Product:
PowerLogic A3 Arc Flash Protection Relay
Model A3F6P
Model A3F12P
Model A3S6P
Model A3S12P
Environment:
Medium- and low-voltage switchgear installations requiring arc flash protection.
Cause:
Users need to understand the flexibility of PowerLogic A3 for various system architectures and selectivity requirements.
Resolution:
PowerLogic A3 supports three operation modes:
- Stand-alone Mode
- Used for simple systems with a single A3F device (full size with power supply).
- Provides independent protection using light-only criteria.
- Example: A3F6P or A3F12P installed in incomer or feeder cubicle.
- System Mode
- Up to 5 A3 devices connected via ArcEM cables.
- Allows sharing of sensor data and commands across devices.
- Supports selective and non-selective schemes for multi-bay systems.
- Limitations: Total cable length ≤ 100 m; max distance between devices = 30 m.
- I/O Peripheral Mode
- Integrates with V321 central unit for advanced arc protection.
- Up to 16 A3 devices can be cascaded.
- Enables complex schemes with current confirmation and IEC 61850/Modbus communication.
Key Considerations:
- Use stand-alone mode for single cubicle protection.
- Use system mode for small switchgear with multiple feeders.
- Use I/O peripheral mode for large installations requiring SCADA integration and advanced logic.
