Description
Product Overview
The Woodward MFR300-71M is an industrial-grade multifunction relay and measuring transducer configured for comprehensive monitoring of single- and three-phase electrical power distribution systems. Equipped with specialized processor logic, it continuously captures accurate True RMS voltage and current inputs, remaining highly resilient against upstream power grid harmonics or switching transients. The “71M” configuration layout integrates native grid-decoupling algorithms, including configurable fault ride-through (FRT) parameters for modern distribution nodes.
Technical Specifications
Verify field chassis part compatibility by referencing these core electrical boundaries:
| Parameter | Value |
| Model Code | MFR300-71M |
| Common Part Numbers | P/N 8444-1065 / 8444-1104 / 8444-1091 |
| Rated Voltage Input | [7] 400/690 V AC (Max Cont. 862 V AC) |
| Rated Current Input | [1] ../1 A AC Secondary |
| Measurement Metrics | V, I, f, P, Q, S, \cos\varphi, Active/Reactive Energy |
| Measurement Accuracy | Class 0.5 (V, I, f) / Class 1.0 (Power & Energy) |
| Network Interfaces | CANopen / Modbus RTU (via RS-485) |
| Discrete Outputs | 4 Configurable Relays + 1 “Ready” Relay |
| Mounting Style | Standard DIN Rail (UM122 Extrusion Profile) |
Operational Realities & Lifecycle Strategy
From a plant asset vulnerability perspective, mixing up configuration variants within the MFR300 family introduces major safety risks. The “71M” variant relies on specific current transformer inputs (typically 1 A configurations versus the 5 A limits seen on standard 15M/75M models). Attempting to substitute this unit with an alternate part number without replacing paired current transformers can saturate physical measuring loops and trigger unexpected circuit breaker trips.
- Stocking Recommendation: Min 1 unit / Max 2 units for critical main generator or distribution tie-breakers.
- Buffer Stock Strategy: Store inside a clean enclosure avoiding unmitigated warehouse condensation.
- Not Recommended For: Direct high-voltage hookups bypassing external potential transformers (PTs) or non-Modbus legacy communication loops.
