Technical Specifications
- Product Model: MDR-2
- Brand: DEIF (Danish DEIF A/S)
- Warranty: One Year
- Control Supply: DC 24 V / AC 85–264 V universal power supply
- Operating Temperature: -20°C ~ +55°C
- Storage Temperature: -40°C ~ +70°C
- Response Time: Typical ≤70 ms fault detection
- Protection Class: Main unit IP40; terminal block IP20
- Accuracy Class: ±1% current measurement accuracy
- Output Frequency: N/A
- Rated CT Input: 1 A / 5 A secondary current transformer input
- Communication Interface: RS485 serial interface; optional remote operator display
- Supported Protocols: Modbus RTU, DEIF proprietary communication protocol
- Overload Capacity: Built-in CT saturation compensation, hardware surge protection, continuous self-monitoring circuit
- Mounting: DIN rail mounting or surface screw mounting
- Dimensions: Standard industrial cabinet modular housing
Product Overview
The DEIF MDR-2 is a marine-approved digital multi-functional differential protection relay designed for three-phase generators, motors and generator-transformer block systems. This protection unit compares incoming and outgoing phase currents to detect internal winding short circuits and leakage faults, effectively preventing severe equipment damage caused by internal generator failures. Marine electrical engineers, power system integrators and maintenance teams utilising DEIF power management equipment rely on the MDR-2 for stable primary differential protection onboard vessels and land-based power stations. Equipped with adjustable tripping characteristics to avoid nuisance tripping from CT saturation, an integrated LCD display and event logging function, it delivers comprehensive fault monitoring, recording and breaker trip logic for critical power generation assets. (Word count: 172)
Key Functions
- Three-Phase Differential Current Protection: Independently monitors L1/L2/L3 phase differential currents. Adjustable operating curves compensate for current transformer saturation imbalance, greatly reducing unwanted false tripping under external short-circuit conditions.
- Expandable Protection Functions: Optional modules support short-circuit protection, overcurrent protection and generator + step-up transformer block differential protection, enabling flexible configuration for different power system architectures.
- Local Display & Fault Event Logging: Onboard LCD visualises real-time current, differential value and setting parameters; internal storage records up to 150 timestamped alarm and fault events to support post-failure analysis and troubleshooting.
- Marine-Grade Reliability & System Integration: Certified for marine applications; RS485 communication uploads status and fault signals to PLC, SCADA and DEIF power management systems. Potential-free relay outputs execute breaker tripping and remote alarm signalling.
Application Scenarios
- Marine Vessel Main & Emergency Generators: Installed inside marine switchboards to protect shipboard synchronous generators. The DEIF MDR-2 complies with DNV-GL marine standards and safeguards power supply safety for cargo ships, offshore support vessels and ferries.
- Offshore Platform Power Generation Systems: Provides main differential protection for platform diesel generators, preventing catastrophic winding faults and maintaining uninterrupted power for drilling and processing equipment.
- Land-Based Industrial Power Plants & Cogeneration Units: Used for medium/low voltage generator and large motor internal fault protection within factory self-generation systems.
- Power Equipment Retrofit & Spare Replacement: Direct compatible replacement for legacy differential relays in existing DEIF power control systems. Standard DIN rail installation minimises cabinet modification during planned maintenance shutdowns.
