Remote monitoring of temperature and vibration
How cloud-based predictive maintenance technology makes it easy
Temperature on critical assets is typically monitored through periodic inspections that occur just a few times throughout the year on average. These are conducted through periodic (oftentimes bi-annual) thermography inspections by an in-house team or third-party contractor. However, these inspections are typically performed while equipment is in a deenergized state, unless they happen to have Infrared (IR) windows installed. If IR windows are present on a switchgear, for example, they can still miss critical connection points that obstruct the IR camera’s view.
Thermography inspection methods typically include aiming an IR camera at the electrical connection or potential hot sources inside the electrical equipment to measure the temperature. Open door thermography inspections demand heavy personal protective equipment (PPE), certified thermographers, and personnel working in the proximity of energized components. Closed door thermography utilizes an IR viewing window installed on the equipment through which the IR camera is directed at the hot spots.
It is often difficult to inspect all critical connections in an electrical panel with the IR window’s limited field of view (FOV) due to the location of the window, equipment complexity, and busbar construction. Though most IR windows are available in sizes ranging from 2” – 20“diameter, a larger FOV is unattainable without using more windows or highly expensive custom windows.
IR windows installation in arc rated equipment further poses a threat to the arc rating of the gear, structural integrity and raises many warranty concerns over the equipment from the manufacturers. IR Thermography is a great tool to identify the temperature anomalies but requires qualified and certified thermographers to perform the work. Most insurance companies and standards require the IR inspections to be performed on systems under an energized condition that replicates the normal operating load or at least on 40% of the rated load.
Inspections performed at non-peak hours due to the facility and personnel availability also affect the relevancy of the measured data. As a result of inspections, thermographers typically issue a detailed report identifying the equipment with the corresponding image, temperature rise finding and recommended actions. Few high-end loss prevention insurance providers and thermographers provide detailed repair estimates and cost avoidance details while taking the production downtime into consideration.
While it is important to conduct temperature inspections, the gaps in datasets prove difficult for catching a critical issue that could occur in between inspections. For example, a three-phase induction motor operating at 18 F above the rated temperature could potentially shorten that equipment’s lifespan by half. Another important factor in determining the reliability and uptime of an electrical system is the condition of the power distribution equipment such as medium voltage and low voltage switchgear, transfer switches, MCCs, and other critical assets.
For a facility with thousands of critical assets, (i.e. motors, switchgears, and MCCs), or even a mere few, regularly checking their operating temperature pays a huge return on investment by preventing unexpected shutdowns. However, transitioning from periodic inspections to a continuous, remote monitoring solution will provide the benefit of foresight into asset health. Maintenance personnel can then schedule out repairs as opposed to performing reactive maintenance. Furthermore, being ahead of the curve increases personnel safety as most workplace accidents occur during reactive maintenance scenarios.
The vibration conversation
When it comes to vibration, rotating machinery is vital to the success of any industrial facility. When a critical pump, compressor, fan, generator or similar type of equipment fails, it can easily bring down an entire production line. A failure can even cause downtime for an entire facility. While degradation in rotating equipment will eventually manifest in increased audible noise, temperature, or current draw, these indicators of damage are often preceded by an increase in vibration across a motor and its bearings.
Vibration analysis is becoming prevalent in facilities that are looking to avoid unexpected downtime by detecting degradation in their rotating assets long before they fail. However, the common practice of route-based vibration analysis can fail to provide sufficient early indication of problems because data is not collected continuously and is not provided remotely or in real-time.
Products that can be quickly and affordably deployed to wirelessly monitor vibration are becoming attractive to reliability engineers and plant managers looking to either improve upon their existing route-based vibration analysis or begin a journey towards data-driven maintenance.
Entry-level vibration monitoring options only allow users to trend overall vibration levels, and they provide similar benefits to a vibration switch on a piece of machinery. These offerings can warn that high vibration amplitude has been detected, but they cannot classify the type of defect the equipment is experiencing or aid in the troubleshooting process.
By looking at not just overall vibration levels, but how those levels trend within very targeted frequency bands, it becomes possible to isolate different types of degradation in a rotating system (e.g. alignment vs. unbalance vs. bearing issues). Additional processing techniques that examine phase, frequency, and time history waveform information can further move an offering from simply detecting the presence of an issue and towards conveying exactly what that issue is and how to resolve it.
On the other end of this spectrum, many high-end vibration monitoring systems are designed to shut down processes immediately when a specific type of vibration event occurs in a given frequency range. As a result, these systems need to both collect and process vibration data continuously, often forcing them to be hard-wired, difficult to install, expensive, and difficult to integrate.
Bringing it all together
A large part of the journey into a remotely monitored maintenance program is finding the right system. But the good news is if you’re looking for a wireless solution, here’s what we know about cloud-based systems that are available today:
- They can automatically alert personnel when anomalous temperatures are reached on equipment that need attention.
- Their user interfaces (UIs) can directly store all real-time data, monitor trends and trigger alerts when irregular thresholds are met.
- They allow alerts to be preconfigured within the UI to provide remediation instructions. These alerts are also capable of being assigned to personnel responsible for asset maintenance so that they will receive an SMS or email alert as soon as it is triggered.
With the ability to provide advanced foresight into equipment health through continuous monitoring, IIoT technology has quickly become the most efficient method for optimal predictive maintenance. Sensors and monitoring devices are capable of being deployed plantwide and can be integrated seamlessly with existing control systems. The result is real-time insights into equipment health with the ability to issue alerts when anomalous temperatures are detected, allowing maintenance teams to safely prepare and schedule out repairs as opposed to rapidly responding to an unplanned downtime event.
Cloud-based remote monitoring is quickly moving the predictive maintenance approach into the world of IIoT with intelligent monitoring systems that are fully configurable for individual users and applications. With a fully deployed wireless system, vibration and temperature monitoring becomes a continuous, remote, and around-the-clock endeavor as opposed to semi-annual, hands-on task.
– Grace Technologies is a CFE Media and Technology content partner.