PAAF074369 ESM-20 Wartsila Engine Safety and Protection Module original

• Brand
  Wartsila
• Model
  PAAF074369 ESM-20
• Product Name
  Engine Safety / Protection Module
• Dimensions
  300 mm × 220 mm × 60 mm
• Weight
  2.3 kg
• Place of Origin
  Finland
• HS Code
  85389000
• Operating Temperature
  -20°C to +70°C
• Storage Temperature
  -30°C to +120°C
• Power Supply
  24 V DC
• Warranty
  12 month
• Status
  new and original

Wartsila ESM-20 (PAAF074369) Technical Specifications

Compatible Systems & Software

Native System Compatibility

The ESM-20 is a core functional module of the Wärtsilä UNIC unified engine control system. It is fully compatible with the WECS-9500 and WECS-9520 marine diesel engine control platforms. The module supports seamless data interaction with the Wärtsilä IAS and IAS-XT integrated ship alarm and monitoring automation systems for real-time transmission of protection status and alarm signals. It also provides standard bus interfaces for data communication with third-party shipboard SCADA and monitoring systems.

Communication Protocols

Equipped with standard industrial communication protocols for multi-level data transmission. The RS-485 Modbus-RTU interface is adopted for field-level real-time data exchange with upper monitoring systems. The internal CAN bus realizes high-speed inter-module data communication among all functional units inside the engine control cabinet.

Configuration & Service Software

Dedicated Wärtsilä ESM-20 Service Tuning Tool is the exclusive official PC software for device configuration. It supports full functions including parameter configuration, alarm threshold calibration, historical fault log query, and firmware upgrade via the onboard RS-485 service port. The module embeds dedicated firmware (typical version: V1.13) to locally store engine protection logic, customized operating setpoints and complete fault history records. No universal third-party software is available for parameter modification or program adjustment; all configuration and maintenance operations require official Wärtsilä service tools.

Input Specifications

Power Input

Nominal Supply Voltage: 24 V DC

Operating Voltage Range: 18 V DC to 30 V DC

Maximum Power Consumption: 20 W

Built-in Protection: Reverse polarity protection and transient overvoltage protection for stable power supply operation

Signal Inputs

Digital Binary Inputs: Supports dry contact and 24 V DC sink/source signal types, applied for emergency stop commands, safety permission signals and external system interlock inputs

Analog Inputs: Accepts standard 4-20 mA current signals and 0-10 V voltage signals to collect key engine operating data, including lube oil pressure, cooling water temperature and exhaust gas temperature

Speed Pick-up Input: Matches magnetic speed sensor signals for real-time engine RPM monitoring, and provides signal basis for overspeed and underspeed protection trips

Output Specifications

Relay Digital Outputs

Protection Shutdown Relay Outputs: Adopts fail-safe dry contact design, dedicated to constructing the engine emergency shutdown trip circuit to ensure safety protection response

Alarm Relay Outputs: Grouped alarm contact outputs for transmitting equipment warning and fault status to the ship’s central automation system

Relay Contact Rating: 24 V DC, maximum 3 A for resistive loads

Communication Output Interfaces

RS-485 Modbus-RTU Interface: Uploads real-time engine operating parameters, active alarm codes and historical fault records to upper-level monitoring systems

Internal CAN Bus Interface: Implements synchronous data exchange and collaborative operation with other Wärtsilä cabinet modules, such as FCM-20 and MCM-20

Local Indication Output

Front-panel Multi-LED Indicators: Displays real-time device power status, active alarms, protection trip events and communication link status for on-site visual inspection

Onboard LCD Display: Supports local real-time viewing of engine operating parameters, fault codes and detailed trip cause information for rapid on-site troubleshooting

Wartsila ESM-20 (PAAF074369) Core Features

Safety-Critical Independent Engine Protection

The ESM-20 is a dedicated safety-grade module designed for Wärtsilä UNIC, WECS-9500 and WECS-9520 marine engine control systems. It features standalone hardwired trip logic that operates independently from the main controller. The module executes critical engine protection shutdowns against overspeed, low lube oil pressure, high cooling water temperature and other abnormal conditions, effectively preventing severe engine failure and operational hazards.

Fail-Safe Trip Circuit Architecture

All engine shutdown relay outputs adopt a standard fail-safe de-energized trip design. In the event of power loss, module malfunction or circuit failure, the safety shutdown contacts will automatically trigger an engine trip. This design complies with international marine safety regulations and ensures zero blind spots in engine safety protection.

Multi-Type Integrated Signal Acquisition

This module supports comprehensive signal sampling without additional conversion modules, covering dry-contact digital signals, 24 V DC sink/source digital inputs, 4–20 mA / 0–10 V analog sensor signals, and magnetic pickup speed sensor signals. It centrally collects all safety-related engine operating parameters to realize integrated signal monitoring.

Dual-Bus Redundant Communication

Equipped with dual communication interfaces for hierarchical data interaction. The internal CAN bus enables high-speed real-time data synchronization and coordinated operation with cabinet internal modules such as FCM-20 and MCM-20. The isolated RS-485 Modbus-RTU interface uploads real-time operating data, alarm information and trip records to ship automation systems and SCADA platforms for remote monitoring and centralized management.

Integrated Local HMI & Fast Diagnosis

The front panel is equipped with multi-indicator LEDs and a built-in LCD screen. LEDs intuitively display power status, active alarms and protection trip events, while the LCD locally presents real-time engine parameters, fault codes and trip root causes. It allows on-site staff to complete rapid fault diagnosis and troubleshooting without external debugging equipment.

Marine-Grade Ruggedized Design

Optimized for harsh marine engine room environments, the hardware features strong resistance to severe vibration, wide temperature variations and electrical transient interference. Adapting to cabinet panel mounting, the module has passed professional marine certification and meets long-term stable operation requirements for shipboard equipment.

Persistent Fault Data Logging

Built-in non-volatile memory automatically stores trip snapshots, alarm sequences and historical fault data. The recorded information will not be lost after power failure, providing complete data support for post-fault root cause analysis, equipment maintenance and operational optimization.

Strict Parameter Access Protection

All safety protection thresholds and core operating parameters are write-protected. Modification and calibration are only permitted via the official Wärtsilä ESM-20 Service Tuning Tool through the dedicated service port, effectively preventing unauthorized parameter tampering and ensuring the safety and stability of engine protection logic.

Wide-Range Adaptive DC Power Supply

Capable of stable operation within 18–30 V DC operating voltage range. Integrated reverse polarity protection, ESD protection and transient overvoltage protection enable the module to adapt to common voltage fluctuations and power disturbances in shipboard 24 V DC power systems.

Modular Pluggable Terminal Structure

All field wiring terminals adopt spring-type pluggable design. It simplifies on-site wiring, system commissioning and module replacement operations, avoids repeated cable crimping, greatly improves maintenance efficiency and reduces wiring failure risks.

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