Kongsberg ACC20 Engine Safety Unit: Redundant Guardian of Industrial Power

Output characteristics:+18 to 32 VDC output, maximum current 500mA.

Design feature: Input channels 14 to 19 are directly hard wired to these output channels. This means that even without CPU involvement, as long as the input conditions are met, the output can take action, greatly improving the speed and reliability of shutdown response.

3.2 Input Channel

The input channels are mainly divided into three categories, all of which require the connection of dry contacts or optocouplers to ensure electrical isolation and signal purity.

3.2.1 Special input for shutdown (with line detection)

Number of channels: 9 channels (input channels 14 to 22, etc.)

Function: Used to connect sensors or buttons that trigger shutdown. These channels not only monitor the switch status, but also continuously detect the integrity of the circuit (disconnection detection).

3.2.2 Ordinary digital input (with line detection)

Number of channels: 6 channels

Function: Used to monitor regular switch signals, such as operating status, mode selection, etc. It also has line detection function.

3.2.3 Safety bypass input

Number of channels: 3 channels (input channels 20 to 22)

Special feature: This is the input channel with the highest security level in the entire module. As described in section 2.2, if the CPU stops working, the internal logic will automatically hard wire these three inputs to the designated solenoid valve output. This is the ultimate guarantee to ensure that a 'hard shutdown' can still be achieved in the event of electronic control system failure.

Chapter 4 Communication and Status Indication

4.1 Dual CAN bus interface

ACC20 ESU uses dual CAN bus as its main communication line. CAN bus is widely used in industrial control and shipbuilding fields due to its high reliability and real-time performance. The dual CAN design provides physical layer redundancy and enhances communication reliability. Through these interfaces, ESU can upload monitoring data, alarm information, and event records to upper level monitoring systems (such as PLC or ship comprehensive alarm systems), while receiving remote configuration or control instructions.

4.2 Onboard LED Status Indication

For the convenience of on-site maintenance and fault diagnosis, the module front panel is equipped with high brightness light-emitting diodes (LEDs). By observing the status of the LED, technicians can quickly understand:

Power status: Whether the main power supply and backup power supply are normal.

Watchdog status: Whether the CPU and software are running normally.

CAN bus status: Whether the communication line is established and whether there are error frames.

This intuitive indicator light design greatly simplifies the initial troubleshooting process, and key information can be obtained without connecting to a computer.

Chapter 5 Technical Parameters and Environmental Adaptability

5.1 Environmental Tolerance

ACC20 ESU is designed for harsh industrial environments, especially in high temperature, high humidity, and high vibration places such as engine compartments and compressor rooms.

Working temperature: -15 ° C to+70 ° C

Storage temperature: -25 ° C to+70 ° C

Humidity: 96% relative humidity (without condensation)

Protection level: IP20 (suitable for installation in clean control cabinets)

Mechanical environment: Complies with IACS E10 standard and can be directly installed on the engine or compressor (with appropriate cabinets).

5.2 Electromagnetic compatibility

The design of ESU meets the requirements of IACS E10 and IEC 60945 for electromagnetic compatibility, which means it can resist electromagnetic interference from industrial environments, while the electromagnetic radiation generated by itself is also within a controllable range, ensuring stable operation in complex electromagnetic environments.

5.3 Physical specifications

Terminal capacity: maximum 2.5 mm ²

Equipment weight: 1.7 kg

Isolation characteristics:

Power supply: non isolated

Digital input: non isolated

Relay output: Isolation

Electromagnetic valve output: non isolated

CAN interface: photoelectric isolation

5.4 Classification Society Certification

One major advantage of ACC20 ESU is its type approval from multiple mainstream classification societies worldwide. This means that the device can be directly applied to ships and ocean engineering platforms without the need for separate certification in each project, greatly simplifying the project approval process.

Certification bodies include: DNV (Det Norske Veritas), LRS (Lloyd's Register), BV (French Classification Society), GL (Germanischer Lloyd, now merged with DNV), RINA (Italian Classification Society), NK (Japan Classification Society), ABS (American Bureau of Shipping), KR (Korean Register of Shipping), PRS (Polish Classification Society), MRS (Russian Classification Society), CCS (China Classification Society).