Implementation of Condition-Based Maintenance (CBM) in a central air conditioning unit by using microcontroller and open-source monitoring platforms

In this work, an online and real-time monitoring system was developed in order to perform Condition-Based Maintenance (CBM). The proposed system named HC 4.0 uses low-cost hardware components such as an Arduino microcontroller and the graphical user interface was designed with the Grafana software, an open-source platform, to measure temperature, relative humidity, compressors currents and motor fan currents in a central air conditioning unit installed at a Brazilian Clinical Hospital named “Hospital das Clínicas da UFG/EBSERH” (HC-UFG/EBSERH). The HC 4.0 solution presents as a result useful information for the maintenance team indicating how to act in a faster, more assertive and effective way regarding the inherent failure modes that are dealt with in a usual work routine. A long-time experiment was conducted for 30 days while the Hospital was operating normally and prominent results were obtained. A designed dashboard through Grafana is used to evaluate the conditions required in order to make an early intervention in the equipment. Furthermore, the system is able to send alerts to the maintainer's cellphones by using a message app such as Telegram, when some parameter goes beyond the pre-defined limits. Additionally, a Failure Mode and Effect Analysis (FMEA) for the central air conditioning unit of the hospital is presented alongside the recommendations to each situation for the maintainer. The results encourage the use and further development of the HC 4.0 approach in order to implement low-cost CBM of Hospital equipment's such as the central air conditioning unit focused on this work.