Description
1. At-A-Glance Executive Brief
- Model: MRA4
- Brand: Woodward
- Part Type: Directional Feeder Protection Relay (HighPROTEC Series)
- Weight: Approx. 4 kg
- System Compatibility: Medium-Voltage (MV) Distribution Switchgear and Ring Main Systems
- Core Protocol: Modbus RTU, IEC 60870-5-103, or optional IEC 61850 / Profibus
2. Technical Introduction
Maintenance teams overseeing medium-voltage distribution networks often encounter complex configuration hurdles or unexpected hardware failures on incoming and outgoing feeder circuits. Replacing a legacy protection asset requires an intelligent numerical device capable of matching existing protection schemes without triggering widespread switchgear modification. The Woodward MRA4 utilizes dual-core processor architecture to execute high-speed directional overcurrent, earth fault, and voltage supervision across radial or meshed grid layouts.
3. Core Technical Specifications
- Manufacturer: Woodward / SEG
- Product Series: HighPROTEC Line (MRA4)
- Current Transformer Inputs: 4 ( configurable for 1A and 5A nominal phase currents )
- Voltage Transformer Inputs: 4 ( measuring up to 800 VAC )
- Binary Inputs / Outputs: 8 Digital Inputs / 7 Output Relays
- Auxiliary Power Supply: Wide-range universal 24–270 VDC / 48–230 VAC
- Enclosure Type: Door mounting or 19-inch rack adapter
- Front Protection Rating: IP54
4. Field Engineer’s Tech Notes
- Polarity and Directional Phase Checks: When commissioning the MRA4 for directional overcurrent (ANSI 67/67N) protection, double-check that current transformer phase orientation matches the voltage vector groupings. Incorrect VT-to-CT phase angle alignment will cause reverse tripping blocks or false tripping during external network faults.
- Firmware and Setting File Conversion: When replacing an older hardware revision with a modern MRA4 unit, always export the parameter file through the Smart view configuration software. Run the software’s conversion utility to adjust minor syntax differences across firmware updates before flashing the new relay to prevent configuration fault flags on boot-up.
5. Adaptive QA & Testing Protocol
Our bench testing protocol utilizes secondary injection test systems tailored for numerical protection assets. For this directional feeder relay, technicians apply simultaneous multi-phase current and voltage vectors to verify directional element thresholds, overcurrent trip curves (ANSI 50/51), and binary output contact response times. Communication port handshakes via RS485 or Ethernet interfaces are thoroughly verified under simulated polling conditions. Official test certificates and calibration logs are available upon request.
6. Buyer’s FAQ
- What warranty is provided with this protection relay?Every unit is supplied with a standard 12-month operational warranty covering electronic and mechanical performance.
- Can this relay be used as a direct retrofit for older SEG or Woodward relays?Yes, the HighPROTEC series offers standardized physical footprints and configuration tools, often paired with SCADApter options for streamlined legacy replacements.
- What is the typical order fulfillment and transit time?In-stock units ship same-day via expedited international courier to ensure zero extended outage windows for your electrical network.
