Alfa Laval EPC 50 Upgrades EPC 70 Separators

Alfa Laval EPC 50 separator control system upgrade to EPC 70 complete guide

Alfa Laval S series and P series separators are widely used for fuel purification, lubricant treatment, and process liquid clarification in industries such as shipbuilding, power, chemical, and food processing. The core of its control system, EPC 50 (Electric Programmable Controller 50), has served countless devices since its launch in 1999 with reliable logic control and basic monitoring functions. However, with the iteration of electronic components, the evolution of automation architecture, and the increasing demand for remote monitoring, data integration, and human-computer interaction in ships and industrial sites, EPC 50 has gradually revealed performance bottlenecks: slow processor speed, non modular I/O modules, discontinuation of spare parts, outdated display screens, and inability to access modern ship management systems such as AMES and IAS.

Since 2010, Alfa Laval has stopped installing EPC 50 on new separators and instead adopted EPC 70 as the standard control system. For the large number of old separators still in service, replacing the entire machine directly is costly, and upgrading to EPC 70 has become the most cost-effective modernization solution.

This article will systematically review the technical details, hardware composition, installation steps, debugging points, and expected benefits of upgrading from EPC 50 to EPC 70 from the perspective of an engineer. It will help on-site maintenance personnel and project leaders smoothly promote the upgrade work, restore the efficient and reliable operation of equipment, and meet the latest requirements of classification societies and environmental regulations.

Why Upgrade: Limitations of EPC 50 and Core Advantages of EPC 70

1.1 Aging issues of EPC 50

Outdated electronic components: EPC 50 uses microcontrollers and I/O chips from two generations ago, and some components have been discontinued, making it difficult to purchase original or compatible spare parts for maintenance.

Non modular structure: The I/O board has high integration. Once a certain input/output channel is damaged, it is usually necessary to replace the entire motherboard, which has high maintenance costs and long cycles.

Limited display screen interface: Using small-sized character LCD or LED indicators, the operation is complex and cannot intuitively display process animations, trend curves, and multilingual alarm information.

Weak communication capability: Lack of standard Ethernet or fieldbus interfaces, making it difficult to access ship automation systems (such as automatic engine room alarm systems and energy efficiency management systems), and unable to achieve remote monitoring and data recording.

Software solidification: Unable to update control logic online, parameter adjustment relies on dedicated handheld devices, and historical operating data cannot be saved.

1.2 Modernization Innovation brought by EPC 70

According to the original factory information, the EPC 70 upgrade package has the following significant advantages:

Classification society certified hardware: The EPC 70 control cabinet and panel adopt marine grade design, meeting the electromagnetic compatibility, vibration, salt spray, and environmental temperature requirements of mainstream classification societies such as DNV, ABS, LR, and BV, ensuring long-term stable operation under harsh working conditions.

Large size touch screen: equipped with a high brightness color touch screen (typical size 7 inches or larger), providing a graphical operation interface that can display the separator process, water seal establishment, slag discharge monitoring, alarm list, and parameter curves in real time. Operators can intuitively complete processes such as start-up, slag removal, and shutdown without the need to refer to manuals.

Modular I/O architecture: EPC 70 adopts independent DI, DO, AI, and AO modules, connected through a backplane bus. Any damaged channel only requires replacement of the corresponding module, greatly reducing repair time. The module comes with diagnostic LED, which can quickly locate the fault point.

The latest generation of electronic components: using mainstream 32-bit processors, high-precision analog inputs (such as PT100, 4-20mA), and solid-state relay outputs, the control accuracy and response speed have been significantly improved.

Modern Automation Architecture: Supports industrial Ethernet protocols such as Modbus TCP, Profinet, EtherNet/IP, and can be easily integrated into ship automation systems or factory SCADA to achieve data acquisition, remote start stop, and alarm push.

Plug and play design: The upgrade package is pre configured for the wiring terminal block of the original EPC 50, and can be directly connected to the corresponding terminal number during on-site installation, reducing drawing comparison time. The software parameters are pre-set to the original machine operating parameters, reducing the difficulty of debugging.

On site evaluation and information collection before upgrading

A successful upgrade relies on a comprehensive understanding of the existing system. Before providing the EPC 70 upgrade package, the Alfa Laval service team will require users to provide the following key information:

2.1 Separators Model and Configuration

Type of separator: S series (such as S 801, S 806, S 926) or P series (such as P 610, P 615, P 618).

Drive motor power: affects heater control and motor protection parameters.

Slag discharge method: manual slag discharge, timed slag discharge, or controlled slag discharge by turbidity meter (such as Alfa Laval MT60)? EPC 70 has optimized the turbidity meter interface to support more sensitive slag discharge control.

Heating system type: electric heating (with contactor/solid-state relay) or steam heating (requiring steam regulating valve actuator).

2.2 I/O configuration of the original EPC 50

Digital input points: such as liquid level switches (water seals, slag ports, oil collection tanks), motor overload, emergency stop, start/stop buttons, etc.

Digital output points: such as motor start stop, heater control, slag discharge valve, alarm indicator light, etc.

Analog input: such as temperature sensor (PT100/thermocouple), pressure transmitter, turbidity meter signal (4-20mA).

Analog output: such as 4-20mA signal for controlling steam regulating valve, speed display output, etc.

2.3 Power Supply and Network Requirements

Power supply voltage: The original EPC 50 is usually 220V AC or 24V DC, while the EPC 70 is compatible with wide voltage inputs, but it needs to be confirmed whether the power module needs to be replaced.

Communication interface: Is it required to access the ship's network? If necessary, the protocol type and IP address planning should be clearly defined.

Only after collecting complete information, the manufacturer will tailor the EPC 70 upgrade package to ensure that all cable lengths, terminal layouts, and installation holes match the original cabinet, achieving true plug and play functionality.

Detailed explanation of typical components and hardware replacement in the upgrade package

According to the service manual, each EPC 70 upgrade package is customized as needed, but typically includes the following core components:

3.1 EPC 70 control cabinet (applicable to SA/PA version)

For SA/PA type separators equipped with independent electrical rooms, the upgrade package provides a brand new control cabinet, which includes:

Main controller (PLC, compliant with IEC 61131-3 standard, supports ladder diagram/structured text programming)

Touch screen (communicates with PLC through Ethernet or serial port)

Modular I/O slots (can insert different numbers and types of modules according to the original configuration)

Power module (providing 24V DC to the controller and sensors)

Terminal block (pre labeled, corresponding one-to-one with the terminals inside the original EPC 50 cabinet)

Installation points: After dismantling the old EPC 50 cabinet, fix the new cabinet in its original position, and then wire it point by point according to the terminal numbers. It is recommended to mark each wire on the drawing to avoid errors or omissions.

3.2 EPC 70 Control Panel (applicable to SU/PU versions)

For compact SU/PU separators (usually equipped with a control panel), the upgrade package offers a brand new panel style touch screen and rear control unit. The panel size is consistent with the original opening and can be directly embedded. The internal wiring is connected to the sensors and actuators on the separator body through prefabricated cables.

3.3 Latest generation steam regulating valve actuator

If the original system uses steam heating and old-fashioned pneumatic or electric actuators (such as Simatic or Honeywell actuators from the EPC 50 era), the EPC 70 upgrade package includes a new generation of intelligent actuators. Its characteristics:

Built in position feedback and PID adjustment function

Accept 4-20mA control signal

Handwheel mechanism facilitates manual operation

Fault alarm output (such as jamming, overheating)

Replacement note: It is necessary to confirm whether the valve body interface size (such as flange or bracket) is compatible. If necessary, valve connections should be replaced simultaneously.

3.4 Electric heater control box (for EPC 50 power unit)

Some of the electric heater power units (SCR or contactor groups) in the EPC 50 system have aged, and the upgrade package can provide a new heater control box. Internal integration:

Solid state relay or contactor (rated current matches the original heater)

Overload protection and cooling fan

Control signal interface (4-20mA or PWM signal from EPC 70)

3.5 MT60 water turbidity meter conversion board

Alfa Laval MT60 turbidity meter is used to monitor effluent turbidity and automatically trigger slag discharge. EPC 50 uses a dedicated interface board, and the EPC 70 upgrade package provides a new version of the conversion board to achieve:

Signal conditioning (converting turbidity meter photoelectric signal into standard 4-20mA)

Diagnostic indicators (sensor contamination, light source aging alarm)

Directly connected to the analog input module of EPC 70

Practical installation and debugging process

4.1 Preparation work

Power off tagging: The main power supply, control power supply, and heater power supply of the separator are all cut off, locked, and a warning is posted.

Marking cables: Use a labeling machine or colored zip ties to mark each cable entering the EPC 50 cabinet, indicating the terminal number and function (such as "DI-03 high water level switch").

Photo recording: Take photos of the wiring inside and outside the old cabinet, terminal layout, and PLC module model as reference for debugging.

Backup parameters: If the old system has readable parameters (such as using a handheld device or software), record the set values as much as possible (such as slag discharge interval time, temperature set value, pressure alarm threshold).

4.2 Demolition of old equipment

Disconnect all external cables (keep markings).

Remove the EPC 50 cabinet or panel and clean the installation area.

Check the insulation and shielding layer of the cable, and repair any damaged areas.

4.3 Installing New Hardware

Fix the EPC 70 control cabinet/panel to ensure reliable grounding.

Connect the cables one by one according to the terminal diagram. Pay special attention to the power line (AC 220V/24V DC), motor control line (contactor coil), and analog signal line (shielded single ended grounding).

Install steam valve actuator (if applicable), connect mechanical linkage and electrical cables.

Install the turbidity meter conversion board and connect the MT60 sensor signal line.

4.4 Power on initial inspection and software debugging

Insulation test: Use a 500V megohmmeter to measure the resistance of the power cable to ground, ensuring it is greater than 1M Ω.

Power supply inspection: Measure whether the 24V DC output in the control cabinet is stable and whether the touch screen starts normally.

I/O forced test:

Manually force output through touch screen, check motor start stop, slag discharge valve action, heater contactor engagement, etc.

Simulate input signals (such as short circuiting liquid level switches, using a signal generator to add 4-20mA), and confirm that the touch screen display value is consistent with the actual value.

Loading application software: Factory preset parameter files are downloaded to the controller via USB or Ethernet. If there is no preset file, manual input is required based on the original EPC 50 parameters.

PID loop tuning: If the steam valve actuator is replaced, the temperature control PID parameters should be re tuned. It is recommended to use the automatic tuning function (such as step response method) first, and then fine tune the proportional band and integration time.

4.5 No load and loaded trial operation

No load test: Start the motor without feeding the separator and observe whether the operating current, vibration, and temperature are normal. Perform manual slag discharge several times and confirm that the valve action timing is correct.

Establish water seal: Establish a water seal according to standard operating procedures and observe whether the water level control is stable.

Feed operation: gradually introduce the medium to be treated, monitor the turbidity, effluent pressure, and heater output after separation. Record a set of operational data (such as temperature, current, turbidity) and compare it with before the upgrade to verify the performance improvement.

Alarm simulation: Manually trigger high/low water level switch, high temperature switch, motor overload, etc., confirm that the alarm display and output are correct.

Common Problems and Solutions (Engineer Site Manual)

Problem 1: The touch screen displays "Communication Error" and there is no communication with the PLC

Reason: Loose Ethernet cable, mismatched IP address, or PLC not powered on.

Solution: Check the network cable plug; Confirm that the PLC and touch screen IP are in the same network segment; Measure the voltage of the PLC power supply.

Problem 2: The steam regulating valve does not operate or has abnormal opening

Reason: The polarity of the 4-20mA control signal is reversed, and the actuator has not undergone stroke calibration.

Solution: Check the wiring of AI/AO terminals; Follow the actuator manual to perform the 'Manual Automatic Calibration' procedure.

Question 3: The turbidity meter reading is always 0 or 100%

Reason: Sensor window contamination, loss of power supply to the conversion board, or short circuit in the signal line.

Solution: Clean the optical window of the turbidity meter; Check the LED indicator light on the conversion board; Measure the 4-20mA circuit with a multimeter.

Problem 4: The separator frequently discharges slag or does not discharge slag

Reason: Improper setting of slag discharge time parameters, overly sensitive turbidity meter threshold, and failure to establish water seal.

Solution: According to the original EPC 50 parameters, check the slag discharge interval, slag discharge time (usually 0.5-2 seconds), and turbidity setting value in EPC 70. Re establish the water seal procedure.

Question 5: Some input points have reversed states

Reason: The original EPC 50 used normally open contacts, the new system defaults to normally closed logic, or there was a wiring error.

Solution: Reverse the input or modify the wiring in EPC 70 software.

Upgraded operations and spare parts management

After completing the upgrade, the equipment enters the EPC 70 era. Suggest users to do the following:

Archive materials: Save electrical schematics, terminal diagrams, software programs (. pro files), touch screen engineering files, and parameter setting tables to the company server and portable hard drive.

Spare parts list: Purchase at least 1 digital input module, 1 analog input module, and 1 touch screen power board as emergency spare parts. Due to their modular design, these components are currently mainstream models and can be obtained long-term through Alfa Laval's official channels or authorized distributors.

Regular inspection: Check whether the wiring terminals inside the control cabinet are loose every quarter; Clean the touch screen surface and ventilation filter; Test the emergency stop circuit.

Software backup: Use a USB flash drive to periodically export configurations through the "backup/restore" function on the touch screen, or transfer them to the engineer's PC via Ethernet.

Benefit analysis and investment return

According to feedback from multiple shipowners and industrial users, upgrading from EPC 50 to EPC 70 can result in the following actual benefits:

Reduce unplanned downtime: The modular structure reduces the mean time to repair (MTTR) from 8 hours to less than 1 hour, making it particularly suitable for rapid repairs during maritime navigation.

Reduce spare parts costs: The price of universal modules is much lower than that of the original EPC 50 dedicated board, and there is no need to stock up on a large number of old boards of different models.

Improve separation efficiency: More precise temperature control and slag discharge logic can reduce the water content and impurities in the fuel, reduce fuel filter blockage and engine wear.

Meeting compliance requirements: The data recording function of modern control systems can help ship owners meet MARPOL's requirements for fuel consumption reporting and emission monitoring.

Extend equipment lifespan: By replacing aging electrical components and actuators, the entire separator system can continue to operate safely for more than 10 years, avoiding high machine replacement costs.