Description
The Woodward / SEG MRG315E5RD (often designated as MRG3-I5E5RD) is a microprocessor-based digital multifunctional generator protection relay. It is engineered for comprehensive electrical monitoring, fault detection, and protection of synchronous and asynchronous generators in industrial power generation plants, marine switchboards, and utility substations.
Commercial and Logistics Status
| Parameter | Value |
| Condition | Factory Sealed / New Surplus / Tested Refurbished (Verify specific unit availability upon inquiry) |
| Availability | Subject to current inventory status |
| Standard Lead Time | 3 to 5 business days for domestic shipments; international freight times vary |
| Warranty | 12 months standard replacement warranty |
| Pricing Note | Price subject to market conditions; contact us for a firm quote |
Technical Specifications
| Parameter | Value |
| Manufacturer | Woodward / SEG (Schaltanlagen Elektroteknik Gerätebau) |
| Product Series | MRG3 Digital Protection Relay Family |
| Catalog / Part Number | MRG315E5RD (MRG3-I5E5RD variant) |
| Device Type | Multifunctional Generator Protection Relay |
| Primary Protection Functions | Overcurrent, short-circuit, earth fault, overvoltage, undervoltage, and frequency protection (package dependent) |
| Current Inputs | 3-phase current monitoring (Standard 5 A secondary CT inputs) |
| Voltage Inputs | 3-phase voltage monitoring inputs |
| Auxiliary Power Supply | Standard industrial control voltage ranges (verify exact rating plate on unit chassis) |
| Communication Interface | Isolated serial or network communication port for parameterization and SCADA integration |
| Mounting Type | DIN-rail or flush panel mounting construction |
| Operating Temperature | −20 to +70°C |
| Enclosure Protection | IP20 housing (requires installation within a sealed switchgear cabinet) |
| Certifications | CE, IEC 60255 compliance, marine type approvals (verify specific revision datasheets) |
Engineering and Field Integration Notes
When retrofitting or commissioning the MRG315E5RD relay within generator control panels, accurate configuration of protection thresholds and CT/VT ratios is mandatory to ensure selective fault clearing.
Integration Guidelines
- CT/VT Ratio Programming: Match the internal relay measurement settings precisely with the primary and secondary ratings of the switchgear current and voltage transformers via the configuration software or front-panel HMI.
- Wiring and Earthing: Terminate all current transformer secondary leads securely. Never open-circuit live CT circuits while the generator is running, as hazardous high-voltage spikes will occur. Maintain low-impedance earth bonding to the enclosure ground terminal.
- Trip Logic Verification: Perform secondary current and voltage injection testing using a calibrated test set to validate trip curve characteristics, relay response times, and output contact actuation to breaker trip coils before synchronizing the generator to the bus.
Frequently Asked Questions
Q: What software is used to program and monitor the MRG315E5RD relay?
A: Woodward/SEG provides dedicated Windows-based communication and parameterization software (such as DIGSI or specific MRG3 service tools depending on the firmware generation) accessed via the front serial interface port.
Q: Does this relay retain configuration settings during a complete loss of auxiliary power?
A: Yes. All protection parameters, configuration curves, and event logs are stored in non-volatile flash memory, preventing data loss during power outages or auxiliary supply switches.
