DEIF GPU/2/GS

Core Technical Specifications

1. Measuring Range: 3-phase line voltage 100–690VAC; frequency 30–70Hz; phase sequence detection
2. Auxiliary Power Supply: 24VDC isolated auxiliary power, tolerance ±20%; consumption max 5W
3. Relay Outputs: Four programmable SPDT relay outputs (alarm or trip mode configurable)
4. Communication Interface: Modbus RTU, CANopen DEIF proprietary bus for genset system networking
5. Display & Operation: Backlit 4-line LCD screen + membrane keypad for on-site parameter programming
6. Environmental Rating: Operating -40°C ~ +70°C; humidity 5–95% non-condensing; IP20 front panel
7. Mounting Standard: 35mm DIN rail mounting; cutout panel mounting compatible
8. Physical Dimension: 120mm(W) × 85mm(H) × 60mm(D); unit weight 350g

Function Features

• Full three-phase continuous monitoring: overvoltage, undervoltage, overfrequency, underfrequency, reverse phase sequence, unbalanced voltage trip
• User-programmable fault delay timers to avoid false tripping from transient grid fluctuations
• Real-time display of voltage RMS value, frequency, fault event code, and relay status on LCD
• Stored fault history log records last 50 fault trigger events with timestamp for maintenance troubleshooting
• Compatibility with all DEIF genset controllers (AGC series, PPC series) and third-party power PLC systems
• Isolated analog input channel accepts external 4–20mA signals for reverse power, current, or temperature monitoring
• Built-in surge protection on voltage measurement terminals to withstand generator switch transient spikes

Working Principle

1. Voltage transformers step down generator high three-phase voltage to low-level measurement signals for internal analog sampling circuit
2. Onboard DSP chip calculates RMS voltage, frequency, and phase rotation sequence at 10ms sampling cycle
3. Compares measured electrical parameters against user-configured protection threshold values stored in non-volatile Flash memory
4. When parameter exceeds threshold for longer than programmed delay time, drive corresponding relay output to trigger generator circuit breaker trip or local audible alarm
5. Transmit all real-time electrical data and fault codes via Modbus/CAN bus to remote power monitoring SCADA system
6. Membrane keypad enables field technicians to modify protection thresholds, reset fault logs, and perform unit self-test without PC software

Material & Structural Characteristics

• Outer Housing: Flame-retardant gray PC plastic DIN rail enclosure with integrated snap mounting clip
• Display Module: Transflective LCD with LED backlight for clear visibility under direct sunlight
• Terminal Blocks: Spring-cage screw terminals with wire anti-slip locking design for vibration-resistant genset cabinet operation
• Internal PCB: Double-sided copper board with isolated measurement and communication circuits to eliminate ground noise interference
• Membrane Keypad: Polyester anti-wear film with silicone tactile buttons for 100,000+ press cycles

Installation Requirements

1. Mount inside genset control cabinet on standard 35mm DIN rail; reserve 15mm vertical clearance between adjacent modules
2. Voltage measurement wiring must use shielded twisted pair cable; separate from high-current generator power cables
3. Auxiliary 24VDC power supply fitted with 2A slow-blow fuse for short-circuit protection
4. All relay trip output wiring must connect to generator breaker trip coil via isolated intermediate relay
5. Ground unit earth terminal to cabinet protective ground bar to suppress electromagnetic interference

Usage Precautions

• Do not modify protection trip delay time below minimum factory preset value to avoid generator winding insulation damage
• Perform annual full functional test by injecting simulated fault voltage signals to verify relay trip action
• Avoid installing adjacent to engine exhaust heat pipes; ambient cabinet temperature must stay below +70°C
• Disconnect auxiliary 24VDC power before accessing internal parameter jumpers or measurement terminals
• Clear fault log records after completing maintenance repair to avoid misjudgment of new fault events