Control Systems: Small Issues That Cause Big Problems

The last thing any manufacturer needs is for a production line to go down thanks to something as mundane as a clogged filter causing a panel to overheat and shut off a VFD. A good way to prevent this is to have your control system inspected by an experienced professional who knows exactly what to look for – and what is overlooked by many in-house maintenance personnel. We asked our Senior Controls Engineer for the “easy-to-miss” issues he most commonly finds when he inspects control systems, and here’s what he told us:

1. Clogged filters. Filters should be checked and replaced regularly. Over time, they can plug up, causing overheating issues. Alternatively, pieces of the filter can break off, allowing unfiltered air from the fan to enter the panel.
2. Loose terminal block connections. Loose connections in power distribution and I/O panels are often invisible to the naked eye. Anywhere you have loose terminals, you have the potential for arcing and higher temperatures, so it’s helpful to use a thermal camera when checking them. Tightening connections on a regular basis, during inspections, can prevent future outages. Loose I/O connections can also lead to unpredictable machine or production line behavior and inaccurate data collection.
3. Exposure to weather, oil, dust, and debris. It’s important to check carefully for evidence of potentially harmful intrusions to the panel. For example, maintenance personnel may add a conduit to hook up a device, then remove it and forget to plug the hole in the panel. The opening exposes everything inside the panel to dust, rain, dirt, and even insects.
4. Obsolete (or hard-to-source) parts. This has been compared to a “ticking time bomb” for some older systems. Many popular platforms are being phased out or are no longer supported by the manufacturer, and some important components – like certain VFDs and PLCs – are virtually obsolete. Sourcing legacy parts for some makes and models has become costly, time-consuming, and difficult. Now may be the perfect time to upgrade preventatively, before sudden downtime becomes an issue.
5. Inadequate system features for uptime needs. For facilities where every second of downtime matters, quickly pinpointing issues with the control system is vital. Newer PLC models offer advanced features that make troubleshooting easier, such as better alarm handling and descriptions. They can also improve operational efficiencies with features like adaptive poppet valve cycle time (for RTOs) which self-corrects thermal imbalances. New PLC models also offer more availability for data collection, providing real-time KPI’s for everything from PMS management to business analytics.