1. Product Overview

2. Key Features

• Dual-Board Architecture: Combines SCM4-1 measurement/sync board + Engine Module (EM) for governor/AVR control.

• Integrated Governor & AVR Control: Supports electronic (0–10 V/4–20 mA) or mechanical (via OPR-1 relay boards) speed/voltage regulation.

• Precision 3-Phase Measurements: Class 0.5 accuracy; direct voltage input (0–690 VAC); CT current inputs (5 A / 1 a secondary).

• Full Synchronisation Suite: Auto-synchronisation (Δf, Δφ, ΔU) + adjustable vector jump protection (5°–30°).

• Expanded I/O: 8× isolated digital inputs, 4× relay outputs (250 VAC / 8 A).

• Communication Interfaces: CAN 2.0A/B, RS485 (Modbus RTU), and DM-4 backplane bus.

• Certifications: CE, IEC 60945 (marine), DNV/GL, ABS, LR, CCS.

• Rack Mount: 6TE width, compatible with DM-4 42TE/60TE racks.

3. Technical Specifications

3.1 Electrical Ratings

3.2 Environmental & Mechanical

4. Application Scope

• Marine Genset Control: Integrated speed/voltage regulation and synchronisation for shipboard generators.

• Industrial Generator Paralleling: Auto-synchronisation and load sharing for diesel/gas gensets in island or grid-tie mode.

• Engine Governor Replacement: Direct control of mechanical governors via OPR-1 relay boards.

• AVR Integration: Electronic or mechanical voltage regulation for synchronous generators.

• DM-4 System Core: Central control unit for DM-4 hydro/gas/land/marine controller racks.

• Backup Power Management: Mains failure (AMF) control and genset sequencing for critical loads.

5. Installation & Wiring

5.1 Installation Requirements

1. Rack Mounting: Insert the module into a 6TE slot in a DM-4 42TE/60TE rack (horizontal only); secure with front panel screws.

2. Ventilation: Maintain ≥25 mm vertical clearance for airflow; do not block rack fans.

3. ESD Protection: Use an anti-static wristband and grounded mat when handling (static-sensitive PCBs).

4. Cable Separation: Route high-voltage (690 VAC) cables at least 10 cm away from low-voltage (24 VDC) control/communication cables.

5.2 Hardware Configuration (Before Power-On)

1. I/O Address Setting: Rotate the front-panel switch to a unique address (0–3). All SCM4.1/4.2 modules must have distinct addresses.

2. Jumper Settings (X10/X13/X20): Set all jumpers to OFF (default for standard operation).

3. OPR-1 Relay Boards: Install if using mechanical governor/AVR; remove for electronic interfaces.

4. CT Ratio Configuration: Set internal jumpers to match current transformer secondary (5 A or 1 A).

5.3 Terminal Wiring (Simplified)

• Voltage Inputs: Use shielded cable; ground shield at the SCM4-2 end only.

• CT Wiring: Short unused CT terminals; never open-circuit CTs (induces hazardous voltage).

• OPR-1 Wiring: Connect relay outputs to mechanical governor/AVR coils.

• Terminal Torque: Tighten to 0.8–1.0 Nm to prevent loose connections and overheating.

• Fusing: Protect 24 VDC supply with a 3 A slow-blow fuse; voltage/CT inputs require no external fusing.

6. Front Panel & Operation

6.1 Front Panel Layout

• LED Indicators (Left to Right)

  • PWR: Solid green = 24 VDC supply OK.

  • RUN: Flashing green (1 Hz) = normal operation; Solid red = fault.

  • SYNC: Solid green = synchronised; Flashing = synchronisation in progress.

  • ALARM: Solid red = fault (vector jump, freq/volt error, engine fault).

  • CAN: Flashing = CAN bus communication active.

  • RS485: Flashing = Modbus RTU communication active.

  • GOV: Solid green = governor control active.

  • AVR: Solid green = voltage regulation active.

• Rotary Switch: I/O address (0–3).

• Jumpers: X10/X13/X20 (function selection, default OFF).

6.2 Startup & Configuration

1. Physical Installation: Mount in DM-4 rack; wire all inputs, outputs, and communication cables.

2. Hardware Setup: Set rotary switch to unique address; install/remove OPR-1 boards as required.

3. Power On: Apply 24 VDC; PWR LED solid green; RUN LED flashes green.

4. Software Configuration (via DM-4 PC Tool)

   • Set system nominal frequency (50 Hz / 60 Hz) and CT/VT ratios.

   • Configure synchronisation parameters (Δf: ±0.2 Hz; Δφ: ±5°; ΔU: ±5% Un).

   • Enable protection functions (vector jump: 15°; U/F: 47.5 Hz; O/F: 52.5 Hz; U<: 360 V; U>: 440 V for 400 V systems).

   • Set governor/AVR mode to electronic (0–10 V) or mechanical (OPR-1).

5. Communication Setup: Configure CAN baud rate (500 kBd) and Modbus address (1–247).

6.3 Normal Operation

• PWR: Solid green; RUN: Flashing green (1 Hz).

• SYNC: Off or solid green (when paralleling).

• GOV/AVR: Solid green (control active).

• ALARM: Off; CAN/RS485: Flashing green (communication active).

• Relays: De-energised (NO open, NC closed).

6.4 Synchronisation & Paralleling Process

1. Measurement: Compares generator and grid voltage, frequency, and phase.

2. Governor Control: Adjusts generator speed to reduce Δf to 0 via the GOV output.

3. AVR Control: Matches generator voltage to reduce ΔU to 0 via the AVR output.

4. Phase Matching: Reduces Δφ to 0°; when all parameters are within range for 1 second, SYNC LED is solid green.

5. Breaker Closure: Energises the closure relay; generator is paralleled to the grid/bus.

6.5 Fault Operation (Engine Overspeed Example)

• ALARM: Solid red; RUN: Solid red.

• Fault Trigger: Engine speed exceeds 110% fn (adjustable).

• Action: Trips generator breaker; de-energises governor output to shut down the engine.

• Reset: Clear fault via DM-4 controller; reset automatically after speed normalises.

7. Safety Precautions

• High Voltage Hazard: Only qualified electrical personnel may install or service this equipment. Disconnect all power sources (24 VDC and 690 VAC inputs) before wiring.

• CT Hazard: Never open-circuit current transformer terminals (induces lethal high voltage).

• ESD Sensitivity: Static electricity can damage internal PCBs. Use anti-static wristband and grounded mat.

• Relay Load Ratings: Do not exceed 250 VAC/8 A per output; suppress inductive loads with external surge protectors.

• OPR-1 Safety: Mechanical governor/AVR circuits may carry high voltage; isolate before servicing.

• No Unauthorised Modification: Do not open the enclosure or modify internal circuits; tampering voids warranty.

• Environmental Limits: Operate only within –20 °C to +70 °C (standard) or –30 °C to +60 °C (marine).

8. Maintenance & Storage

8.1 Regular Maintenance (Every 12 Months)

1. Visual Inspection: Check for loose terminals, damaged wiring, corrosion, or discolouration (overheating).

2. Cleaning: Wipe front panel with a dry, lint-free cloth; no liquid cleaners (avoid water ingress).

3. LED Check: Verify all LEDs operate correctly.

4. Terminal Tightness: Retorque all terminals to 0.8–1.0 Nm.

5. Functional Test: Inject 3-phase voltage/current; test synchronisation, protection thresholds, and governor/AVR control.

6. Insulation Resistance: Measure ≥1 MΩ @ 500 VDC between voltage/CT inputs and ground.

7. OPR-1 Check: Inspect relay contacts for wear (if used).

8.2 Storage Guidelines

• Packaging: Store in original anti-static packaging with desiccant.

• Environment: 10–30 °C, 30–70% RH, dry, clean, and dust-free.

• Protection: Avoid direct sunlight, extreme temperatures, and mechanical shock/vibration.

• Duration: Shelf life ≤5 years; inspect for ESD damage and test basic functions before use if stored longer.

9. Troubleshooting

10. Warranty & Disclaimer

• Model: SCM4-2 (SCM4.2) Synchronisation, Control & Engine Module.

• Warranty Period: 24 months from delivery date (under normal installation and use per manual).

• Warranty Exclusions: Misuse, overvoltage, lightning, water ingress, unauthorised modification, improper maintenance, CT open-circuit, or OPR-1 relay wear.

• Specifications Subject to Change: Manufacturer reserves the right to update specifications without prior notice.

• Liability Limitation: Manufacturer is not liable for indirect or consequential damages (e.g., downtime, lost revenue, equipment damage).

• Documentation Version: 1.0 (2026); latest manual available at www.deif.com.