Condition Monitoring: Enhancing Not Replacing Maintenance Teams
The Meerkat condition monitoring system was developed in early 2017 for a customer who had a critical piece of equipment in a location that was not easily accessible. It was their main pump on a floating pontoon at a quarry. If the pump failed, the feed to the processing plant stopped. So they needed a way to monitor it.
Due to the location, a wired system was out of the question, so a wireless solution was needed. The Fletcher Moorland team found a suitable sensor with a wireless node and receiver. This was combined with a standalone HMI for signal processing. Whenever a predetermined level of vibration or temperature was breached, a signal light lit on the 'shore-side' equipment and the maintenance office. The maintenance team were then able to react to the problem.
Pretty quickly, with the growth in awareness of the Industrial Internet of Things and Industry 4.0, interest in the system grew. The team knew that it needed to develop the system further. An early addition was a GSM gateway which enables the system to SMS message a mobile phone when an alarm is breached. This allowed an entire maintenance team to be alerted to a problem happening wherever they were.
The next development involved moving sensor data from a standalone system to the cloud and a web-based dashboard. Anyone with the correct access could then view the data; trends could be seen, alarms and notes acknowledged.
As customers saw the advantages of the condition monitoring system, requests to monitor more than vibration and temperature began to be made. As a result, sensors monitoring current, humidity, airflow, pressure, oil condition, fluid level and sound level were added to installed systems.
As the solution continues to develop, the latest evolution is the addition of edge computing capabilities. Monitoring systems can create a massive amount of data, and edge computing can handle this more effectively and efficiently. Couple this with a Raptor gateway, and the system can benefit from artificial intelligence and machine learning capabilities which can help identify potential issues starting to happen with equipment.
Of course, one issue often faced is concern that condition monitoring solutions will replace people and cost jobs. But, like many forms of automation technology, that isn't the case. What should happen is that existing staff are able to step away from mundane, time-consuming tasks, or unplanned interruptions to focus their expertise in areas where they can add more value to a business – and gain greater satisfaction from their work.
Condition monitoring solutions should be the first line of maintenance. For example, if there is a threshold breach, say a fan's vibration velocity has changed, someone needs to investigate.
Used correctly, condition monitoring solutions reduce the need to drop everything when something unexpectedly fails, or spend time investigating or checking something that doesn't need to be checked. It enables maintenance teams to focus more on proactive rather than reactive tasks.
A recent situation caught by a Meerkat remote condition monitoring system is a good example.
At a site that produces bricks, the Meerkat system alerted that there was an over-temperature alarm on one of the dryer motors. As the dashboard graph in Figure 1 shows, the temperature jumped significantly from a normal operating temperature of around 25-30°C to almost 100°C.
In this case, the site maintenance team were alerted to investigate what was causing the over-temperature warning. It turned out that the force vent fan on the motor had failed. A new one was pulled from stores and replaced, and very soon the temperature was within normal limits.
Left unattended, the motor would have undoubtedly stopped working due to a motor winding insulation failure caused by the excess heat. Vibration monitoring would have probably not seen anything. Thermal surveys would not have seen anything until the force vent unit failed, and being there at that exact moment is very unlikely. It is also unlikely that there would have been any warning of this failure, so having a continuous monitoring system was the saviour.
Having a system installed has, without question, saved this site from having product quality issues from the non-uniform drying of its product; it has probably saved them from having waste product and lost profit as well.
The early warning meant that the maintenance team were not required to spend valuable time dealing with the aftermath of a motor failure and were able to instead spend that time on other tasks which supported the ongoing productivity and reliability of their plant.
As well as allowing teams to carry out more beneficial work, condition monitoring solutions can also reduce the need for staff to carry out some more hazardous tasks. Take the maintenance and testing of roof fans. If the condition is being monitored, it negates the need for periodic checks, where a staff member must face the risks associated with working at height. The number of times this needs to be done can be significantly reduced to only when maintenance has been shown to be required.
And no matter how sophisticated a condition monitoring solution is, there is no alternative to the intuition of a trained engineer. Someone with experience 'walking the floor' can still pick up on signals that something is not right. They may notice sounds that might not be picked up by vibration monitoring, smells that could indicate a change, or movement that is not normal. With the core monitoring being taken care of automatically, more time is also available for this type of activity. But the experience is still very much needed.
It is also true that maintenance teams have generally not grown following the COVID pandemic; indeed, many have shrunk. And alongside this, we have a skills shortage across the engineering sector. So allowing those staff who are carrying out maintenance functions to focus their time on more valuable tasks is invaluable to many businesses today.
Some vendors are selling condition monitoring solutions as an alternative to maintenance resource but that simply isn't the case. Expertise is needed to understand where to place sensors and interpret the information they provide.
Indeed, for businesses introducing condition monitoring solutions, their maintenance teams see real benefits rather than threats to their roles.