A metal processor had a four-compressor system that was well controlled by a compressor sequencer. System operation was very well monitored by a system of pressure, power, and flow instruments that fed system operating characteristics back to the maintenance supervisor.
One day before the Christmas holiday, the supervisor noticed that the variable speed drive (VSD) compressor was not operating properly. It was failing to respond to any pressure changes — and low pressure events were occurring — a sign something was going wrong. He scheduled a visit by his service provider, but before they could arrive, the compressor started working perfectly again. He called it his Christmas miracle, the machine had healed itself!
Of course, we can all predict what happened next. A few days later, on New Year’s Day, the compressor decided to fail again, resulting in a costly emergency call out. The miracle had turned into a holiday turkey! Once the service technician arrived and replaced a faulty pressure transducer, all again was good with the world, at least inside this industrial plant.
The Maintenance Manager’s New Year’s resolution: Always heed the warnings from his measurement system.
