Product Overview

In modern ships, critical infrastructure backup power systems, or small power plants, generator sets are essential for ensuring a continuous power supply. However, reliably, efficiently, and automatically operating one or more generator sets requires an intelligent “brain” to coordinate the complex relationship between the engine, generator, and power grid. The DEIF DLQ144-PC-NB is precisely this “brain”—a compact, fully functional generator set controller. It is not just a display instrument, but a complete control system integrating monitoring, protection, logic control, automatic synchronization, and load sharing, integrating dispersed instruments, relays, and logic circuits into a single robust unit.

Understanding the core value of the DLQ144 lies in recognizing how it injects “automation” and “reliability” into generator set management. For a single unit, it can automatically complete the entire process of starting, accelerating, voltage building, and switching on the power supply based on external commands (such as a mains power failure signal). It continuously monitors dozens of parameters such as oil pressure, water temperature, voltage, and frequency, issuing alarms or performing shutdown protection immediately if any parameter exceeds its limits, effectively preventing equipment damage. For multiple units operating in parallel, its automatic synchronization function precisely adjusts the voltage and frequency of the unit to be paralleled, capturing the optimal moment for switching on, achieving smooth and shock-free parallel operation; its load sharing function automatically adjusts the throttle of each unit according to the set ratio or demand, achieving even load distribution, optimizing fuel efficiency and unit lifespan. Therefore, the DEIF DLQ144-PC-NB is a key intelligent device for improving the automation level, operational safety, and management efficiency of power generation systems. Technical Specifications

Product Model: DLQ144-PC-NB (Suffix usually indicates specific configuration, such as display type, enclosure, input type)

Manufacturer: DEIF (Danish Electric Industrial Fish)

Product Series: DLQ Series

Power Supply Voltage: Typically supports a wide range of DC (e.g., 9-35 V DC) or AC/DC power supply

Display: LCD screen with backlight, used to display parameters, status, and alarms

Input Channels:

Analog Inputs: Used to monitor generator three-phase voltage, three-phase current, frequency, power factor, active/reactive power, engine speed, oil pressure, water temperature, fuel level, etc.

Digital Inputs: Used to receive dry contact signals such as remote start/stop signals, circuit breaker position, alarm acknowledgment, mode selection, etc.

Output Channels:

Relay Outputs: Used to control engine start, fuel valve, preheating, shutdown, generator circuit breaker opening and closing, etc.

Analog Outputs: Optional, used to output speed setpoint signals (to the governor) and voltage setpoint signals (to the automatic voltage regulator) for load sharing and speed/voltage regulation.

Protection Functions:

Engine Protection: Overspeed, underspeed, low oil pressure, high water temperature, start failure, etc.

Generator/Grid Protection: Overvoltage, undervoltage, overfrequency, underfrequency, overcurrent, reverse power, etc.

Control Functions:

Automatic/Manual start/stop sequence

Automatic synchronization (for parallel operation)

Active power (kW) and reactive power (kVAr) load sharing

Automatic start on mains failure

Multiple operating modes (manual, automatic, test)

Communication Interface: Typically equipped with an RS485 serial interface, supporting Modbus RTU protocol, for integration into SCADA (Supervisory Control and Data Acquisition) systems.

Protection Rating: The front panel is typically IP65 rated, suitable for control cabinet door mounting. Main Features and Advantages

The core competency of the DEIF DLQ144-PC-NB lies in providing a highly integrated, intuitive, and powerful “all-in-one” control solution for small and medium-sized generator sets. It successfully integrates complex parallel control logic, comprehensive protection functions, and a user-friendly interface into a compact device, significantly reducing system integration complexity and greatly improving the automation level and operational reliability of the power generation system.

Its primary advantage is its high level of functional integration and compact design. It replaces the traditional combination of separate components (such as governors, synchronizers, protection relays, and instrument panels) with a single device, greatly simplifying wiring and layout within the control cabinet, reducing failure points, and making the system easier to install and maintain. Secondly, its powerful automatic parallel control capability is a key differentiator from basic controllers. Its built-in automatic synchronizer enables fast and smooth parallel operation, while the precise load sharing algorithm (controlling the governor and automatic voltage regulator via analog outputs) ensures even load distribution among parallel units, preventing “load hogging” or “reverse power,” and improving the overall efficiency and stability of the power plant.

Intuitive User Interface and Operation: A clear LCD screen displays all key operating parameters in digital and bar graph formats. Intuitive menu navigation and buttons make parameter setting, mode switching, and alarm querying very convenient, lowering the technical threshold for operators.

Comprehensive Protection and Safety: It features dozens of built-in protection functions covering both the engine and generator, providing comprehensive protection for expensive power generation assets and preventing equipment damage due to various faults.

Flexible Communication and Monitoring: Through Modbus RTU communication, single or multiple controllers can be easily integrated into a supervisory control and data acquisition (SCADA) system or a ship alarm and monitoring system, enabling remote monitoring, data logging, and centralized management to meet modern management needs.

Robust and Reliable Design: Derived from marine equipment design standards, it can withstand harsh environments with high temperatures, high humidity, and vibration, ensuring long-term stable operation. Technical Overview

The DEIF DLQ144-PC-NB is a versatile and compact genset controller designed for the management, protection, and automatic paralleling of diesel or gas generator sets. It integrates a wide range of functions into a single unit, serving as the central intelligence for both standalone and multiple generator applications.

Its core capabilities include comprehensive monitoring of all critical engine and generator parameters (voltages, currents, frequency, power, speed, temperatures, pressures), and a full suite of protective functions to safeguard the equipment. For single sets, it manages the complete automatic start/stop sequence. For multiple sets operating in parallel, it features built-in automatic synchronization and load sharing (both kW and kVAr) functionality, ensuring smooth grid connection and proportional load distribution between units. The controller features a user-friendly LCD interface for local operation and provides a Modbus RTU communication port for integration into broader SCADA or monitoring systems. Known for its robustness and reliability, the DLQ144-PC-NB is a popular choice for marine electrical plants, land-based standby power systems, and small-scale power generation applications requiring a high degree of automation in a compact form factor.

Application Areas

The DEIF DLQ144-PC-NB is widely used in applications requiring highly automated and reliable power supply, especially in scenarios involving the parallel operation of single or multiple generator sets. It is a classic choice for the marine industry and industrial backup power systems.

On ships, it serves as the standard control core for both main and emergency generator sets. Whether for merchant ships, offshore vessels, or yachts, the DLQ144 automatically manages the start/stop, paralleling, de-paralleling, and load transfer of multiple generator sets, ensuring stable and economical operation of the power plant under different operating conditions (such as sailing, docking, and cargo handling). On land, it is widely used in critical backup power systems for data centers, hospitals, communication base stations, and factories. When the mains power fails, it automatically starts the backup generator set and quickly connects to the load, ensuring continuous power supply to critical facilities. In addition, it is also suitable for small island microgrids, mining areas, or construction sites, enabling automatic paralleling and load management of multiple units. Marine and Offshore: Basic unit for main generator set control, emergency generator set control, and power management systems.

Critical Facility Backup Power: Automatic control systems for diesel generator sets in data centers, hospitals, airports, and financial centers.

Industrial and Infrastructure: Temporary or permanent power stations for mines, remote areas, and construction sites.

Combined Heat and Power/Microgrids: Generator unit control within small distributed energy systems.

Integration and Configuration Highlights

Successfully integrating the DEIF DLQ144-PC-NB into a power generation system is a system engineering project involving high-voltage, low-voltage, mechanical, and control logic. The key lies in correct signal connections, precise parameter settings, and comprehensive functional testing.

First, accurate hardware wiring must be completed:

Power Supply and Grounding: Provide a stable, compliant DC (or AC) control power supply and ensure proper grounding of the controller.

Analog Sensor Inputs: Correctly connect signals from current transformers, voltage transformers, temperature sensors, pressure sensors, etc. Pay special attention to the polarity, transformation ratio, and ensure the secondary side of the CT is not open-circuited.

Digital Inputs: Connect passive dry contact signals such as remote start/stop, circuit breaker auxiliary contacts, and emergency stop.

Relay Outputs: Connect to loads such as the engine starter motor, fuel solenoid valve, and circuit breaker closing/opening coils. Note the relay capacity; intermediate relays should be added if necessary.

Speed ​​and Voltage Control: If automatic load sharing is required, connect the controller’s analog output (usually 4-20mA) to the remote setpoint input of the engine’s electronic governor and the generator’s automatic voltage regulator.

Secondly, software configuration is crucial. Access the settings menu via the controller’s front panel buttons and configure each item:

System Parameters: Set the generator’s rated voltage, current, frequency, power, engine rated speed, etc.

Protection Settings: Carefully set all alarm and shutdown protection values ​​(such as overspeed value, low oil pressure value, overfrequency value, etc.) according to the equipment manufacturer’s requirements.

Control Logic: Set the starting sequence (pre-lubrication, preheating time), number of starts, cooling shutdown time, synchronization parameters (voltage difference, frequency difference, phase angle difference), load sharing ratio/droop characteristics, etc. Communication Parameters: Set the Modbus address, baud rate, parity bits, etc., to match the upper-level monitoring and data acquisition system.

Finally, systematic functional testing must be performed:

Simulation Testing: Without starting the engine, simulate various sensor signals and digital inputs to verify the display, alarm, and output action logic.

Local Manual Testing: Manually start/stop the generator set on the controller and check that all steps are functioning correctly.

Automatic Mode and Protection Testing: Test the automatic start/stop sequence and simulate critical faults (such as overspeed, low oil pressure) to verify that the protective shutdown function acts immediately and accurately.

Parallel Function Testing (if applicable): Perform automatic synchronization, load sharing and transfer, and decoupling tests on two units to verify their stability and accuracy.

Lifecycle and Procurement Recommendations

The DEIF DLQ series controllers are a very mature, classic, and time-tested product series in the field of marine and industrial power generation control. The DLQ144, as one of the main models in this series, has a large installed base worldwide. Currently, this series may be in the later stages of its “maturity phase.” DEIF has launched newer, more advanced controllers such as the GPC-3 series, but the DLQ series still has continuous demand in the spare parts market due to its stability and large number of existing systems.

Therefore, the procurement strategy needs to be clear: For the maintenance, replacement of faulty controllers, or one-to-one upgrades of existing power generation systems (especially marine power plants or critical backup power systems), the DLQ144-PC-NB is the preferred spare part to ensure complete compatibility without modifying peripheral wiring and programs. Its parameter settings can usually be backed up and restored, and replacement is relatively convenient. For new generator set projects or major renovations, it is strongly recommended to consult DEIF or its authorized dealers to evaluate and adopt their latest generation of controller products to obtain more advanced communication interfaces (such as Ethernet), more powerful processing capabilities, and richer functions. When purchasing, be sure to provide the complete model number DLQ144-PC-NB and pay attention to its hardware/firmware version. It is recommended to stock a controller of the same model as a spare part for critical generator sets.