LSU-113DG
May 12, 2026

LSU-113DG

Description

1. Product Overview

The LSU‑113DG (DEIF Uni‑line series) is a compact, high‑precision active load‑sharing controller for diesel and gas generator sets. It builds on the LSU‑112DG with extended load‑sharing logic (‑P>), offering enhanced stability and flexibility for multi‑genset parallel operation, island mode, and grid‑connected power plants.
Integrated power (kW) and frequency (Hz) transducers eliminate external measurement devices. The unit interfaces with mechanical governors via two on‑board speed‑control relays or with electronic governors through optional EPQ‑96‑2 / EPN‑110DN electronic potentiometers.
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2. Key Features

  • Enhanced Load Sharing (‑P>): Improved proportional load balancing for mixed‑size gensets.

  • Integrated Transducers: Built‑in active power and frequency sensors (no external devices needed).

  • Dual Control Modes:

    • Isochronous: Zero droop for tight frequency regulation (stand‑alone/grid).

    • Constant Power: Fixed setpoint for base‑load operation.

  • Speed Control: Two relay outputs (increase/decrease) for mechanical/electronic governors.

  • LED Status Indicators: Power, Run, Frequency, Load, Control, and ‑P> status.

  • Adjustable Settings: Gain, droop, load setpoint, frequency trim, and ‑P> threshold via front‑panel potentiometers.

  • Fail‑Safe: Disables paralleling outputs if generator breaker opens or mains fail.

  • Certified: CE, IEC 60068, DNV‑GL, and ABS marine approvals.


3. Technical Specifications

3.1 Electrical Ratings

ParameterSpecification
ModelLSU‑113DG (Enhanced Active Load Sharing Unit)
ManufacturerDEIF A/S
Controlled Gensets1 (parallel with up to 16 units)
Input Signals
– Voltage100–440 VAC, 50/60 Hz (L1/L2)
– Current5 A AC (CT secondary, 3 phases)
– Frequency Range40–70 Hz (45–65 Hz nominal)
– Aux Supply24 VDC ±20% (18–32 VDC), ≤10 W
Outputs
– Speed Control Relays2 × 250 VAC / 5 A (NO/COM)
– Paralleling SignalsIsolated, 0–10 V / 4–20 mA (load share)
Measurement Accuracy
– Power±0.5% FS @ 25 °C
– Frequency±0.1 Hz
Isolation2.5 kV AC (1 min) I/O‑to‑supply

3.2 Environmental & Mechanical

ParameterSpecification
Operating Temperature–20 °C to +70 °C (standard); –40 °C to +70 °C (marine)
Storage Temperature–40 °C to +85 °C
Humidity5–95% RH non‑condensing
Vibration2–13.2 Hz: ±1 mm; 13.2–100 Hz: ±0.7 g
EnclosureIP20 (front), IP00 (rear)
Dimensions (W×H×D)155 × 110 × 75 mm
WeightApprox. 0.8 kg
Mounting35 mm DIN rail or base plate

4. Application Scope

  • Land‑Based Gensets: Stand‑alone, grid‑parallel, or multi‑genset CHP plants (enhanced load sharing for mixed sizes).

  • Marine Power Systems: Shipboard genset parallel operation, island mode, and DP (Dynamic Positioning) support.

  • Offshore Platforms: Oil/gas rig load sharing, black‑start, and frequency control.

  • Hybrid Systems: Diesel/gas gensets with wind/solar/battery storage (load smoothing and peak shaving).

  • Emergency Power: Critical infrastructure backup (hospitals, data centres) with paralleling capability.


5. Installation & Wiring

5.1 Installation Requirements

  1. Mounting: Install on 35 mm DIN rail or base plate; ≥50 mm clearance for ventilation.

  2. Environment: Avoid direct sunlight, moisture, corrosive gases, and excessive vibration.

  3. ESD Protection: Use anti‑static wristband when handling (static‑sensitive components).

  4. Cable Separation: Separate AC voltage/current cables from DC control cables by ≥10 cm.

5.2 Terminal Wiring (Simplified)

Terminal GroupDescriptionWire Gauge
Power

1–224 VDC (+/−)1.5 mm²
3Chassis ground (PE)2.5 mm²
AC Voltage (L1/L2)

4–5100–440 VAC (line‑line)2.5 mm²
AC Current (CTs)

6–85 A AC (CT secondary, 3 phases)2.5 mm²
Speed Control Relays

9–10Relay 1: Increase speed (NO/COM)1.5 mm²
11–12Relay 2: Decrease speed (NO/COM)1.5 mm²
Paralleling I/O

13–14Load share signal (0–10 V / 4–20 mA)1.0 mm²
15Breaker status input (24 VDC)1.0 mm²
Wiring Notes
  • CT Connection: Use 5 A CTs (3 phases); ensure correct polarity (L1/L2/L3).

  • Shielded Cables: Use twisted‑pair shielded cables for current/voltage signals; ground shield at one end only.

  • Terminal Torque: Tighten terminals to 0.8–1.0 Nm to avoid loose connections.

  • Fusing: Protect AC voltage inputs with a 2 A slow‑blow fuse.


6. Front Panel & Operation

6.1 Front Panel Layout

  • LED Indicators (Left to Right)

    • POWER: On = 24 VDC present.

    • RUN: Flashes = normal operation; solid = fault.

    • FREQ: On = frequency within tolerance; flashing = out of range.

    • LOAD: On = load > 10%; flashing = overload (>110%).

    • CONTROL: On = speed control active (increase/decrease).

    • ‑P>: On = enhanced load sharing active; flashing = load imbalance detected.

  • Potentiometers (Adjustments)

    • GAIN: Load‑sharing response speed (0–100%).

    • DROOP: Speed droop (0–5%) for parallel stability.

    • LOAD SET: Target active power setpoint (0–100% of genset rating).

    • FREQ TRIM: Fine frequency adjustment (±2 Hz).

    • ‑P> THRESHOLD: Imbalance limit for enhanced load sharing (0–20%).

6.2 Startup & Configuration

  1. Power On: Apply 24 VDC; POWER LED on; RUN LED flashes.

  2. AC Inputs: Connect L1/L2 voltage and CT current inputs; FREQ LED lights if frequency is 40–70 Hz.

  3. Mode Selection:

    • Isochronous: Set DROOP to 0%; for stand‑alone or grid‑parallel frequency control.

    • Constant Power: Set LOAD SET to desired kW; for base‑load operation.

  4. Load Sharing Tuning:

    • Adjust GAIN (start at 50%) for stable load balance ( no hunting).

    • Set ‑P> THRESHOLD (start at 10%) to activate enhanced balancing for imbalances above the set value.

  5. Frequency Trim: Use FREQ TRIM to match grid frequency (±0.1 Hz) before paralleling.

  6. Parallel Operation: Close generator breaker; LOAD LED indicates load level; CONTROL LEDs show speed control activity; ‑P> LED lights if enhanced sharing is active.


7. Safety Precautions

  • High Voltage Hazard: Only qualified electricians may install/service; disconnect all power (DC + AC) before wiring.

  • CT Safety: Never open‑circuit CT secondary terminals (risk of lethal voltage).

  • ESD Risk: Static electricity can damage the PCB; use anti‑static protection.

  • Relay Output Caution: Speed control relays switch high voltages; ensure load ratings are not exceeded.

  • No Unauthorised Modification: Do not open the enclosure; tampering voids the warranty.

  • Environmental Limits: Do not operate outside –20 °C to +70 °C (standard) or –40 °C to +70 °C (marine).


8. Maintenance & Storage

8.1 Regular Maintenance (Every 6 Months)

  1. Visual Inspection: Loose terminals, damaged wiring, corrosion, or overheating signs.

  2. Cleaning: Wipe front panel with dry cloth; no liquid cleaners.

  3. LED Check: Verify POWER/RUN/FREQ/LOAD/CONTROL/‑P> LEDs operate correctly.

  4. Calibration Check: Compare measured power/frequency with external meter (±0.5% accuracy).

  5. Cable Tightness: Retorque terminals to 0.8–1.0 Nm.

  6. Relay Test: Verify speed control relays activate when load is unbalanced.

8.2 Storage Guidelines

  • Condition: Original anti‑static packaging, 10–30 °C, 30–70% RH.

  • Environment: Dry, avoid direct sunlight/extreme temps.

  • Duration: Shelf life ≤2 years; inspect for ESD damage before use if stored longer.


9. Troubleshooting

Fault PhenomenonPossible CauseSolution
POWER LED OffNo 24 VDC / blown fuseCheck power wiring; replace 2 A fuse
RUN LED Solid (Fault)AC input missing / CT open circuit / overvoltageCheck L1/L2 voltage; verify CT connections
FREQ LED FlashingFrequency <40 Hz or >70 HzAdjust genset speed to 45–65 Hz
LOAD LED Off (No Load)CT wiring fault / genset not loadedCheck CT polarity; increase load on genset
Load Sharing Unstable (Hunting)GAIN too high / DROOP too low / ‑P> threshold too lowReduce GAIN; increase DROOP (1–3%); adjust ‑P> threshold
Cannot Parallel (Frequency Mismatch)FREQ TRIM misadjusted / grid frequency driftTrim frequency to match grid (±0.1 Hz)
‑P> LED FlashingPersistent load imbalance > thresholdCheck genset sizing; adjust GAIN/‑P> threshold

10. Warranty & Disclaimer

  • Model: LSU‑113DG Enhanced Active Load Sharing Unit.

  • Warranty Period: 24 months from delivery date (normal installation/use).

  • Warranty Exclusions: Misuse, overvoltage, lightning, water ingress, unauthorised modification, or improper maintenance.

  • 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).

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



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