Description
1. Product Overview
2. Key Features
Dual-Board Architecture: Combines SCM4-1 measurement/sync board + Engine Module (EM) for governor/AVR control.
Integrated Governor Control: Supports mechanical (via OPR-1 relay boards) or electronic speed governors.
Integrated AVR Control: Supports mechanical voltage regulation (OPR-1) or electronic AVRs.
3-Phase Precision Measurement: Class 0.5 accuracy (0–690 VAC direct; 5A/1A CT inputs).
Full Synchronisation Suite: Auto-sync (Δf, Δφ, ΔU) + vector jump (5°–30°) protection.
Expanded I/O: 8× digital inputs, 4× relay outputs, plus engine control outputs.
Communication: CAN 2.0A/B, RS485 (Modbus RTU), DM-4 backplane bus.
Certifications: CE, IEC 60945 (marine), DNV/GL, ABS, LR, CCS.
Rack Mount: 6TE width, fits DM-4 42TE/60TE racks.
3. Technical Specifications
3.1 Electrical Ratings
| Parameter | Specification |
|---|---|
| Model | SCM4-2 (SCM4.2) |
| Manufacturer | DEIF A/S |
| Part Number | 4921240469 (standard) |
| Power Supply | |
| – Auxiliary | 24 VDC ±20% (18–30 VDC), ≤20 W |
| – Backplane | 5 VDC (from DM-4 rack) |
| Measurement Inputs | |
| – Voltage | 2× 3-phase (L1/L2/L3/N), 40–70 Hz, 0–690 VAC |
| – Current | 3× CT (5 A / 1 A secondary), Class 0.5 |
| – Accuracy | ±0.5% (25 °C); ±1.0% (–20 °C to +70 °C) |
| Engine Control (EM Board) | |
| – Speed Governor | PWM/analog output or relay outputs (OPR-1) |
| – Voltage Regulator | PWM/analog output or relay outputs (OPR-1) |
| – Governor Interface | Electronic (0–10 V/4–20 mA) or mechanical (OPR-1) |
| Protection & Sync | |
| – Sync Range | Δf: ±0.5 Hz; Δφ: ±10°; ΔU: ±10% Un |
| – Vector Jump | 5°–30° (adjustable) |
| – Frequency | 40–70 Hz (U/F: 90–100% fn; O/F: 100–110% fn) |
| – Voltage | 80–120% Un (U<: 80–100%; U>: 100–120%) |
| Digital I/O | |
| – Inputs | 8× isolated (24 VDC, 550 V isolation) |
| – Outputs | 4× relay (NO/COM/NC, 250 VAC/8 A, 2.2 kV isolation) |
| Communication | |
| – CAN | 2× CAN 2.0A/B (125–1000 kBd) |
| – RS485 | Modbus RTU (9600–38400 Bd) |
| – Backplane | DM-4 internal bus (address 0–3) |
3.2 Environmental & Mechanical
| Parameter | Specification |
|---|---|
| Operating Temperature | –20 °C to +70 °C (marine: –30 °C to +60 °C) |
| Storage Temperature | –40 °C to +85 °C |
| Humidity | 5–95% RH non-condensing |
| Vibration | 2–13.2 Hz: ±0.7 mm; 13.2–100 Hz: ±0.5 g |
| Enclosure | IP20 (front/terminals); conformal coated PCB |
| Dimensions (W×H×D) | 30.48 × 160 × 120 mm (6TE, double euro) |
| Weight | Approx. 1.0 kg |
| Mounting | DM-4 42TE/60TE rack (horizontal) |
4. Application Scope
Marine Genset Control: Integrated speed/voltage regulation + synchronisation for ship generators.
Industrial Generator Paralleling: Auto-sync and load sharing for diesel/gas gensets (island/grid-tie).
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 for DM-4 hydro/gas/land/marine controller racks.
Backup Power Management: Mains failure (AMF) and genset sequencing for critical loads.
5. Installation & Wiring
5.1 Installation Requirements
Rack Mounting: Insert into 6TE slot in DM-4 42TE/60TE rack (horizontal only); secure front screws.
Ventilation: ≥25 mm vertical clearance; avoid blocking rack fans.
ESD Protection: Anti-static wristband + grounded mat (static-sensitive PCBs).
Cable Separation: High-voltage (690 VAC) cables ≥10 cm from low-voltage (24 VDC) cables.
5.2 Hardware Configuration (Before Power-On)
I/O Address: Rotary switch (0–3); all SCM4.1/4.2 modules must have unique addresses.
Jumpers (X10/X13/X20): Set all to OFF (default mode).
OPR-1 Boards: Install if using mechanical governor/AVR; remove for electronic interfaces.
CT Ratio: Internal jumpers for 5 A or 1 A secondary.
5.3 Terminal Wiring (Simplified)
| Terminal | Description | Wire Gauge |
|---|---|---|
| 3-Phase Voltage Inputs | ||
| L1/L2/L3/N (Gen) | Generator Voltage (0–690 VAC) | 2.5 mm² |
| L1/L2/L3/N (Grid) | Grid Voltage (0–690 VAC) | 2.5 mm² |
| CT Inputs | ||
| CT1/CT2/CT3 | Generator CT (5 A/1 A) | 1.5 mm² |
| Auxiliary Supply | ||
| +24V/GND | 24 VDC ±20% | 1.5 mm² |
| PE | Chassis Ground | 4 mm² |
| Digital I/O | ||
| DI1–DI8 | 24 VDC Digital Inputs | 1.5 mm² |
| RO1–RO4 | Relay Outputs (250 VAC/8 A) | 1.5 mm² |
| Engine Control (EM) | ||
| GOV+/GOV– | Speed Governor Output (PWM/analog) | 1.5 mm² |
| AVR+/AVR– | Voltage Regulator Output (PWM/analog) | 1.5 mm² |
| Communication | ||
| CAN_H/CAN_L | CAN Bus (125–1000 kBd) | 1.5 mm² |
| RS485_A/B | Modbus RTU | 1.5 mm² |
Voltage Inputs: Shielded cable; ground shield at SCM4-2 end only.
CT Wiring: Short unused CTs; never open-circuit CTs (hazardous voltage).
OPR-1 Wiring: Connect relay outputs to mechanical governor/AVR coils.
Terminal Torque: 0.8–1.0 Nm (prevent loose connections/overheating).
Fusing: 24 VDC supply: 3 A slow-blow fuse; voltage/CT inputs: no external fusing.
6. Front Panel & Operation
6.1 Front Panel Layout
LED Indicators (Left to Right)
PWR: Solid green = 24 VDC OK.
RUN: Flashing green (1 Hz) = normal; Solid red = fault.
SYNC: Solid green = synchronised; Flashing = sync in progress.
ALARM: Solid red = fault (vector jump, freq/volt error, engine fault).
CAN: Flashing = CAN bus active.
RS485: Flashing = Modbus RTU active.
GOV: Solid green = governor control active.
AVR: Solid green = voltage regulation active.
Rotary Switch: I/O address (0–3).
Jumpers: X10/X13/X20 (default OFF).
6.2 Startup & Configuration
Physical Installation: Mount in DM-4 rack; wire all inputs/outputs/communication.
Hardware Setup: Set rotary switch to unique address; OPR-1 installed/removed as needed.
Power On: Apply 24 VDC; PWR solid green; RUN flashes green.
Software Configuration (DM-4 Tool)
System frequency (50/60 Hz), CT/VT ratios.
Synchronisation: Δf ±0.2 Hz, Δφ ±5°, ΔU ±5% Un.
Protection: Vector jump 15°, U/F 47.5 Hz, O/F 52.5 Hz, U< 360 V, U> 440 V (400 V system).
Governor/AVR: Electronic (0–10 V) or mechanical (OPR-1) mode.
Communication: CAN baud 500 kBd, Modbus address 1–247.
6.3 Normal Operation
PWR: Solid green; RUN: Flashing green.
SYNC: Off or solid green (paralleling).
GOV/AVR: Solid green (control active).
ALARM: Off; CAN/RS485: Flashing green.
Relays: De-energised (NO open, NC closed).
6.4 Synchronisation & Paralleling
Measurement: Compares generator/grid voltage, frequency, phase.
Governor Control: Adjusts generator speed (Δf → 0) via GOV output.
AVR Control: Matches generator voltage (ΔU → 0) via AVR output.
Phase Matching: Δφ → 0°; when all params in range for 1s, SYNC solid green.
Breaker Closure: Energises closure relay; generator parallels to grid/bus.
6.5 Fault Operation (Engine Overspeed)
ALARM: Solid red; RUN: Solid red.
Trigger: Engine speed > 110% fn (adjustable).
Action: Trips generator breaker; de-energises governor output (shuts down engine).
Reset: Clear fault via DM-4 controller; reset after speed normalises.
7. Safety Precautions
High Voltage Hazard: Only qualified electrical personnel to install/service. Disconnect all power (24 VDC + 690 VAC) before wiring.
CT Hazard: Never open-circuit CT terminals (induces lethal voltage).
ESD Sensitivity: Static electricity damages PCBs. Use anti-static wristband/grounded mat.
Relay Loads: Do not exceed 250 VAC/8 A per output; suppress inductive loads.
OPR-1 Safety: Mechanical governor/AVR circuits may have high voltage; isolate before servicing.
No Unauthorised Modification: Do not open enclosure or modify circuits; voids warranty.
Environmental Limits: Operate only –20 °C to +70 °C (standard) or –30 °C to +60 °C (marine).
8. Maintenance & Storage
8.1 Regular Maintenance (Every 12 Months)
Visual Inspection: Loose terminals, damaged wiring, corrosion, discolouration.
Cleaning: Wipe front panel with dry lint-free cloth; no liquid cleaners.
LED Check: Verify all LEDs operate correctly.
Terminal Tightness: Retorque to 0.8–1.0 Nm.
Functional Test: Inject 3-phase voltage/current; test sync, protection, governor/AVR control.
Insulation Resistance: Voltage/CT inputs to ground ≥1 MΩ @ 500 VDC.
OPR-1 Check: Inspect relay contacts for wear (if used).
8.2 Storage Guidelines
Packaging: Original anti-static packaging + desiccant.
Environment: 10–30 °C, 30–70% RH, dry/clean/dust-free.
Protection: Avoid direct sunlight, extreme temps, shock/vibration.
Duration: Shelf life ≤5 years; test functions before use if stored longer.
9. Troubleshooting
| Fault Phenomenon | Possible Cause | Solution |
|---|---|---|
| PWR LED Off | No 24 VDC / blown internal fuse | Check DC wiring; replace 3 A fuse. |
| RUN LED Solid Red | Module fault / invalid config / engine fault | Reboot; verify rotary switch/jumpers; check engine sensors. |
| SYNC LED Not On | Δf/Δφ/ΔU thresholds too tight / governor/AVR fault | Widen sync tolerance; check GOV/AVR outputs. |
| ALARM LED On (Vector Jump) | Loose voltage wiring / unstable grid | Retorque voltage terminals; check grid stability. |
| GOV LED Off (No Speed Control) | Governor wiring error / OPR-1 fault (mechanical) | Check GOV wiring; test/replace OPR-1. |
| CAN/RS485 LED Off | Communication wiring / baud rate error | Check bus wiring; verify baud rate/address. |
10. Warranty & Disclaimer
Model: SCM4-2 (SCM4.2) Synchronisation, Control & Engine Module.
Warranty Period: 24 months from delivery (normal installation/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 right to update specs without notice.
Liability Limitation: Manufacturer not liable for indirect/consequential damages (downtime, lost revenue, equipment damage).
Documentation Version: 1.0 (2026); latest manual at www.deif.com.
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