Finding faults on complex electrical control systems can be a real challenge, especially when there is a production manager breathing down your neck wanting to know how soon the line will be fixed.
So what approaches can maintenance staff take to get the bottom of the issue quickly?
Favoured methods can include calling the expert i.e. perhaps there is someone on site who knows in detail how certain systems work. Another approach could be to try a solution that has previously worked e.g. if a sensor failed before, perhaps changing that same sensor again may be a good fix.
Both these methods can work, but are they reliable? What if the expert is not available, or leaves the company? What if the fault is actually different, so applying a known fix actually wastes time, money and effort?
Faster and more reliable fault finding can be achieved by implementing three basic steps:
1) Train staff on the system drawings – make sure up-to-date drawings are available, showing control circuits, PLCs, safety relays, inverter drives etc. Training staff to understand the drawings, such as how to read references and symbols, will give them the right platform to start tacking faults. Otherwise they may be just guessing at how things interact, and that could lead to longer downtime and more mistakes being made.
2) Be familiar with test equipment – misreading a value or not correctly using a tester can easily lead to more problems. In the worst case, it may even cause danger e.g. not properly understanding how to test if a circuit is dead. Anyone who needs to fault find should understand their test equipment in depth.
3) Know what to expect – the key to successful fault finding is based on knowing what to expect. Maintenance staff should be able to understand the core working principles of components and circuits, so that when faced with a problem they can systematically identify what is working as it should and what isn’t.
Armed with the right drawings and a solid understanding of testers and components, maintenance staff can confidently home into the source of the fault quickly and effectively. This helps reduce line downtime and costs, and leads to a more effective operation.