Bearing Monitor Design – RoPax Ferry

The existing 24 year old main bearing monitoring systems on three sister ships had become increasingly unreliable and inaccurate, contributing to machinery failure. Spares were also obsolete.

We were commissioned to replace the main bearing monitoring units in the ECR whilst retaining the existing probes and wiring.

An off the shelf system was sought but due to the unusual probe characteristics i.e. negative temp co-efficient (NTC) thermistors, this option was unavailable at acceptable cost.
This led us to designing our own proprietary main bearing monitoring system, able to interface to the existing probes fitted.

1239119240-34965100The system was based upon software programmable sensor interface modules for linearization and galvanic isolation and a class approved Mitsubishi PLC for data display and alarm handling.

A colour graphical HMI (Human Machine Interface) was used for presentation of bar graph style readouts and alarm screens.The complete design, construction and class approval of the three systems was carried out over an eight week period.

All of the documentation was submitted and approved by class (Det Norske Veritas).

Installation and testing was completed in less than one day per ship.The system has been designed to interface to virtually any type of probe/sensor and including Pt100, Thermocouple, Resistance, Thermistors (NTC/PTC), Voltage, Current.

The system is ideal for replacement of existing systems or for retrofitting to installations without monitoring installed.