November 2020

14 | Plant & Works Engineering www.pwemag.co.uk November 2020 Maintenance Matters Focus on: Thermal Imaging H eat is often an early symptom of equipment damage or malfunction, making it important to monitor in preventive maintenance programs. Using thermal imaging regularly to check the temperature of critical equipment makes it possible to track operating conditions over time and quickly identify unusual readings for further inspections. Thermography (otherwise known as thermal imaging) uses infrared-sensitive cameras to inspect buildings, electrical equipment and rotating machinery to find faults associated with heat loss or gain. Infrared cameras have developed significantly over recent years: some modern thermal imaging cameras are now so small they can fit in the palm of a hand. Therefore, thermal cameras are often the first inspection tool a technician thinks to use as part of their preventive maintenance program. They can swiftly measure and compare heat signatures for all equipment on the inspection route, all without interrupting operations. Applications include HVAC maintenance to electrical inspection and building envelope surveys. Electrical and mechanical systems tend to get hot before they fail; air duct leaks and excess moisture are often colder than their surroundings. By detecting these temperature anomalies, thermal imaging allows facilities maintenance crews to take corrective action and avoid costly maintenance and repair. Another advantage of thermal imaging is it can pinpoint energy losses in a building without any destructive testing methods. Pairing the thermal imaging camera with methods such as ‘Blower Door’ systems can speed up inspections immensely. The camera is a reliable non-contact instrument that can scan and visualize the temperature distribution of entire surfaces quickly and accurately. Thermography programs have contributed to substantial cost savings around the world. If the temperature is noticeably different from previous readings, facilities can then use other maintenance technologies - vibration, motor circuit analysis, airborne ultrasound, and lube analysis - to investigate the source of the problem and determine the next course of action. For best results, all maintenance technologies should be integrated into the same computer system, so that they share the same equipment lists, histories, reports and work orders. Once the infrared data is correlated with data from other technologies, the actual operating condition of all assets can be reported in an integrated format. To calculate the savings at a facility, estimate the costs of unplanned equipment failures. Then factor in human resources, costs for parts, and lost revenue from specific production lines. It would be wise for the maintenance manager to keep a record of machine asset availability, production output, and the total maintenance costs over time. Those numbers will help calculate the return on a thermal imaging and maintenance investment. According to Fluke, studies by the US Federal Energy Management Program (FEMP), estimate that a properly working preventive maintenance program can lead to savings of 30 to 40%. Cameras to look at Costing around £10k, the Fluke Ti480 PRO Handheld Thermal Imaging Camera can be used to inspect electrical and mechanical apparatus and identify potential problems, such as faulty components, before they become critical issues. This allows the maintenance team to address and correct issues without the need for extensive downtime, this, in turn, reduces costs. The rugged, pistol grip design allows the thermographer to focus on their surroundings rather than the camera. The camera can capture a surprising level of detail with the high thermal sensitivity, allowing the smallest temperature anomalies to be isolated and displayed in a SuperResolution mode – 4x the standard resolution. The new Exx-Series cameras from FLIR Systems are designed to help professionals detect the early signs of building issues, identify hot spots, troubleshoot electrical and mechanical systems, and prevent problems before they cause damage that leads to expensive repairs. The E96, with a 640x480 resolution and eight-times digital zoom, is the most advanced Exx-Series thermal camera to date. It delivers improved measurement results over the greatest distance to target, so professionals can safely diagnose electrical faults or locate hidden Monitoring equipment performance and scheduling maintenance when needed reduces the likelihood of unplanned downtime due to equipment failure. This saves the costs of “reactive maintenance” fees and equipment repair costs, while extending the lifespan of machine assets. Andy Pye reports. Thermal imaging: cost-effective contribution to preventive maintenance