DEIF RMP-112D

Core Technical Performance Parameters

Measurement & Protection Threshold Range

• Overload Protection Setting Range: 25% – 125% of generator rated power
• Reverse Power Protection Setting Range: 0% – 25% negative power (anti-motoring)
• Hysteresis Band: 2% of full measurement scale to prevent relay chattering
• Adjustable Trip Delay Timer: 0–20 seconds independent delay for overload and reverse power fault
• Response Speed: Maximum 400 ms fault detection response time

Electrical Measurement Spec

• Supported Network: Three-phase AC generator system
• Rated Measuring Voltage: 440 V AC max, 400 V AC nominal marine generator standard
• Current Transformer Secondary Input: 5 A standard CT secondary signal
• Auxiliary Supply Voltage Options: 110 V AC / 230 V AC / 24 V DC optional
• Relay Output Contacts: Two independent mechanical relay outputs (Overload relay B, Reverse power relay C)
• Contact Rating: 250 V AC / 24 V DC, 8 A resistive load per contact
• Contact Mechanical Service Life: 200,000 switching operations under rated resistive load

Environmental & Mechanical

• Operating Ambient Temperature: -25 °C to +70 °C continuous operation; UL certified max 60 °C
• Temperature Drift Error: Max 0.2% full scale per 10 °C temperature variation
• Input-output Isolation Strength: 3250 V AC 50 Hz one minute withstand isolation
• Mounting Standard: 35 mm standard DIN rail mounting
• Protection Class: IP20 front panel, cabinet installation only
• Net Weight: 0.63 kg

Function & Feature Highlights

1. Dual integrated protection functions in single compact module: generator overload protection and reverse power anti-motoring protection
2. Independent adjustable delay timers for two fault types to eliminate nuisance tripping from transient power fluctuation
3. Front panel rotary potentiometers for direct on-site threshold calibration without software configuration
4. Independent LED status indicators for power supply, overload fault, reverse power fault for rapid on-panel fault diagnosis
5. High isolation between measurement CT circuit, auxiliary supply and relay output contact circuits to avoid ground loop interference
6. Marine vessel type approved, fully compliant with DNV, ABS marine generator safety standard
7. Wide auxiliary supply voltage options compatible with land and marine generator control panel power systems
8. Relay contact configurable as normally energized or normally de-energized via internal wiring jumper for flexible safety interlock design

Working Principle

1. Three-phase voltage and CT secondary current signals from generator main circuit are input to internal precision power measurement circuit.
2. Real-time three-phase active power calculation continuously compares measured power value against user-adjusted overload and reverse power threshold settings.
3. If forward power exceeds overload setpoint or negative reverse power exceeds anti-motoring threshold, internal timer starts timing according to configured delay value.
4. When delay timer completes countdown, corresponding mechanical relay contact pulls in to trigger generator circuit breaker trip signal or prime mover shutdown interlock circuit.
5. Front panel LED illuminates to indicate active fault condition; fault status remains latched until generator power load recovers to normal safe operating range.

Material & Structural Composition

• Front Panel: Impact resistant black ABS plastic with transparent LED viewing window and calibration potentiometer access holes
• Main Housing: Flame-retardant plastic DIN rail mounting housing
• PCB Substrate: FR4 fiberglass circuit board, conformal anti-humidity coating for marine cabinet environment
• Measurement Components: High precision voltage/current sampling transformers, wide temperature range operational amplifiers
• Output Components: Sealed electromagnetic mechanical relays with arc suppression diodes
• Calibration Parts: Multi-turn carbon film precision rotary potentiometers
• Terminal Blocks: Nickel-plated copper screw terminals with stainless steel locking screws

Installation Requirements

1. Standard 35 mm top-hat DIN rail vertical mounting inside generator control panel cabinet
2. Maintain minimum 10 mm horizontal clearance between adjacent relay modules for heat dissipation
3. CT secondary wiring must adopt dedicated shielded twisted pair cable, CT circuit strictly prohibited from open-circuit live operation
4. Three-phase voltage measurement wiring must match generator phase sequence correctly; wrong phase sequence causes power measurement inversion error
5. Auxiliary supply wiring must connect to stable uninterruptible control power source, avoid voltage fluctuation during generator startup

Application Scenarios

• Ocean-going vessel diesel generator parallel operation control panels
• Land-based backup emergency generator set protection cabinet
• Offshore platform auxiliary power genset safety monitoring system
• Hospital, data center critical backup generator protection
• Marine yacht and passenger ship power management system

Operation & Maintenance Precautions

1. CT secondary circuit must never be disconnected while generator is running; open CT circuit generates dangerous high voltage and burns module internal sampling transformer
2. Calibration potentiometer adjustment must be completed under generator no-load stable operating state for accurate threshold setting
3. Avoid installation adjacent to high-current contactors and frequency drives to reduce electromagnetic interference affecting power measurement accuracy
4. Conduct annual calibration of protection threshold setting with three-phase power standard calibrator to eliminate long-term drift error
5. Relay contact load must not exceed rated 8 A resistive load; inductive trip coil loads require external surge absorption protection diode