Description
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | IRI1-I5E05D |
| Manufacturer | Woodward |
| Product Type | Microprocessor Earth Fault (Ground Fault) Protection Relay |
| Protection Functions | ANSI 50N / 51N sensitive earth fault, zero-sequence overcurrent |
| Rated CT Secondary Current | 5 A (model suffix I5; 1 A version also available in series) |
| Operating Threshold Range | 0.05 – 5 A (CT secondary side), DIP-switch selectable |
| Time Characteristics | Definite-time 0.05–10 s; IDMT inverse-time per IEC 60255 |
| Filtering / Algorithm | DFFT digital filtering, harmonic & DC component rejection |
| Auxiliary Supply | 230 V AC/DC universal (110 V versions available in series) |
| Output Contacts | 2 × SPDT (Form C), 250 V AC / 5 A and 30 V DC / 5 A |
| Front Panel Indication | Power, Ready, Earth Fault, Trip, Alarm LEDs + RESET button |
| Reset Modes | Auto-reset after fault cleared; manual via panel button or external dry contact |
| Measurement Input Burden | ≤ 0.2 VA per CT input |
| Frequency Compatibility | 50 Hz / 60 Hz (DIP-selectable) |
| Mounting | DIN rail / panel / door / 19-inch rack, withdrawable chassis |
| Dimensions (H × W × D) | 260 × 72 × 138 mm |
| Weight | Approx. 1.0 kg |
| Operating Temperature | −20 °C to +60 °C |
| Storage Temperature | −40 °C to +85 °C |
| Humidity | 5 – 95 % RH, non-condensing |
| Enclosure Protection | Front panel IP54; internal wiring side IP20 |
| Standards & Certifications | CE, UL, IEC 60255, Class I Division 2 |
Main Features and Advantages
Sensitive ground fault detection that protects what overcurrent relays miss. The core strength of the Woodward IRI1-I5E05D is its ability to detect residual leakage currents down to 0.05 A on the CT secondary side—equivalent to very small insulation degradation currents in high-resistance grounded generator and motor windings. By vector-summing the three-phase currents through a core-balance CT (CBCT) or neutral CT, the relay isolates genuine in-zone earth faults from healthy-system imbalances, giving operators an early warning long before a fault escalates into winding damage, cable fire, or an unplanned outage.
DFFT filtering for dependable discrimination. Industrial networks are full of waveform distortion: magnetizing inrush on transformer energization, variable-frequency drive harmonics, DC offsets, and external phase faults all generate current components that can fool simpler relays. The Woodward IRI1-I5E05D extracts only the fundamental zero-sequence component through DFFT-based digital filtering, which dramatically reduces out-of-zone maloperation while preserving fast in-zone response. The result is a relay that stays stable through system transients yet trips decisively when a real ground fault appears.
Flexible, software-free configuration. All operating parameters—pickup current, time delay, frequency, time characteristic, and reset behaviour—are set through front-panel DIP switches and internal jumpers. The 0.05–5 A threshold range and 0.05–10 s delay range let protection engineers grade the relay precisely against feeder, transformer, and breaker curves. Choose definite-time operation for fixed coordination schemes, or IDMT (IEC 60255) curves where grading is required over a wide fault-current range. A separate jumper selects automatic reset once the fault clears, or latched operation that requires a panel RESET press or an external dry-contact reset—ideal for applications where every trip must be formally acknowledged.
Two independent SPDT outputs for separate alarm and trip paths. The Woodward IRI1-I5E05D dedicates one SPDT contact to an alarm or pre-warning signal (routed to the DCS, SIS, or annunciator) and a second high-power SPDT contact to the actual trip circuit, capable of directly driving breaker trip coils, motor outlet breakers, and excitation switches. This segregation means an early-stage earth leakage can be logged and investigated without immediately shedding a critical load, while a developed fault still receives unconditional fast clearance.
Rugged industrial design with full local diagnostics. A sealed front panel, IP54 operator interface, and LED suite showing supply healthy, ready, fault type, and trip state allow maintenance staff to assess relay status at a glance without test equipment. The withdrawable chassis, DIN-rail / panel / door / 19-inch rack mounting options, and wide −20 °C to +60 °C operating range make the Woodward IRI1-I5E05D straightforward to install in new panels and equally easy to retrofit into existing cubicles—an important advantage when replacing obsolete or end-of-life ground fault relays.
