5 minute read
Keeping a sharp eye on critical systems
from Renew Magazine - Quarter 2, 2021. Condition monitoring and predictive maintenance focus
by touchwavegc
Renew spoke to Matt Fletcher, Managing Director of Fletcher Moorland, to find out how Meerkat, his company’s wireless condition monitoring system, is saving time and money for a facilities management company.
Completed in 2018, the London-based commercial skyscraper, the Scalpel, is 190m high and comprises 38 floors. Naturally, the facilities management (FM) company looking after the building is keen to ensure its tenants are comfortable. A complex HVAC system manages the interior environment, and this must remain operational 100% of the time, with all efforts made to avoid system failures or breakdowns.
In other buildings managed by the FM company, there is a planned maintenance programme designed to ensure system parts and components are checked, and where necessary replaced, before there is any chance of failure. But the company recognised that a condition-based maintenance approach would be more effective – not only from a cost perspective but also from the quality of the building’s environment. With maintenance staff only required when a need was identified, they could be freed up for other work. Plus, components costs could be reduced with parts replaced less frequently, only when they demonstrated a reduction in performance.
It was the Meerkat solution from Fletcher Moorland that the FM company chose for its building, as the company’s Managing Director, Matt Fletcher, explained: “With the project out to tender, we were approached by the building’s facilities team who had heard about Meerkat and were keen to find out about the system.
“Many condition monitoring systems are highly complex, and it can require a deep understanding of vibration analysis to use them properly. We intentionally designed Meerkat to be very simple from a user’s point of view. We took a demo system to the site and left it online for a few weeks so the facilities company could get a feel for it. They loved it, and it was indeed the simplicity that won us the contract.”
The system installed at the Scalpel has 158 sensors, or points – sensing vibration, temperature, and where needed, speed output from the inverter drives. Some assets have more than one sensor attached; for example, a large pump may need two sensors on the pump itself and two on the motor. How this is set up is where the expertise of the installation team comes into play. Fletcher Moorland’s installation team are vibration analysis certified and use a combination of their experience, and the parameters set out in ISO 10816 to establish how best to monitor each of the assets.
“While self-installation, plug-and-play systems are available, understanding where to place the sensors will make a huge difference to the performance of the monitoring system,” continued Matt.
SIMPLIFIED CONNECTIVITY
One of the advantages of the Meerkat system is that it is wireless. In the Scalpel, there is a plant room in the basement and one on the top floor. This would require vast amounts of cable – challenging to route through the building and adding to the project cost. Each point is connected to a network node powered by a battery that lasts on average two years. All the nodes are then meshed together over a wireless network sending data to a central gateway in the building. The data from each point is given an identifier and date stamp before being sent off-site to the cloud over a mobile GSM network. This approach allows the system to be installed anywhere without interfering with existing infrastructure
“This is another advantage of the Meerkat system,” Matt added. “There is no requirement for someone to monitor the data graphs physically. If the thresholds are exceeded, an email or text message is sent to alert the relevant user.”
The Meerkat software takes the data, and after a baseline is established, thresholds are set. Ongoing data is then monitored, and if any of the thresholds are breached, an alarm can be triggered.
This is another area where the software working behind the scenes is intuitive which makes the enduser’s involvement in the system relatively simple. While the vibration and temperature sensors monitor direct conditions on the assets, Meerkat can also cater for speed fluctuations with sensors on the inverters, which can help identify where changes in the thresholds might be needed. If, for example, the speed of a fan drops, the vibration threshold is reduced. Simply setting a static temperature or vibration level to trigger an alarm could cause false alarms or lead to issues being missed.
When an alarm is triggered, the data history can then be studied to see what patterns have emerged, helping to establish what may have happened. A steady change over time could indicate gradual wear, while a more sudden change would suggest some form of failure. For example, in a brickworks also employing a Meerkat system, the vibration data from one asset shot up suddenly. When the team went to inspect the kiln extractor fan, they discovered that one of its brackets had fractured. It was quickly re-secured but had the fan failed, the kiln would have been compromised and its entire output ruined.
In terms of the impact Meerkat is having at the Scalpel, it is relatively early days. However, the maintenance team’s hours have already been reduced, as have replacement component costs. And an unexpected benefit has been discovered. Through the ongoing monitoring of some of the system’s pumps, the potential to make savings in energy use has been identified – something which would have otherwise gone unnoticed.
A FLEXIBLE SOLUTION
In an automotive manufacturer’s paint plant, the paint would build up on the ventilation system’s fan impellers, sending them out of balance. To avoid this leading to motor failure and unplanned downtime, the manufacturer needed maintenance teams to regularly inspect the fans. As well as the time it took the maintenance team, this also caused a degree of disruption to production.
A Meerkat system was designed and installed at the site, monitoring the fan’s vibration. With the maintenance team only needing to get involved when an alarm is triggered by the system detecting a threshold breach, significant maintenance hours have been saved, resulting in reduced production downtime.
