Start with one question: is this compressor working harder because the plant needs more air, or is it running when nobody expects it to? Run hours help answer that question if they are recorded alongside the operating conditions. A longer run on its own is a reason to investigate, not a fault diagnosis.
Choose a signal that means what you think it means
Ask the equipment owner whether the controller already exposes a supported motor-run indication or hour counter. Keep motor running, loaded operation and machine available as separate states. An enabled machine might be stopped; a running compressor might be unloaded. If the controller offers only a cumulative total, differences between valid readings can show added hours, but not necessarily when each start happened.
Where there is no usable controller signal, have a qualified installer evaluate an approved status output or a suitable external sensing method. A current measurement may help infer whether a motor is running, but the inference needs checking against real operating states. Do not treat current as a direct reading of air output, load or electrical energy. Leave existing controls and protection in charge.
Build a record you can compare
- Label the asset and record when each state began, when it ended and where the signal came from. Keep unknown intervals separate from stopped time.
- Compare similar periods: production shift with production shift, or closed hours with closed hours. Note planned cleaning, unusual demand, equipment changes and maintenance.
- Give a named maintenance owner a short review list: unexpected after-hours starts, changed run patterns or missing data. Include the timestamps and supporting observations so they can check what happened.
Illustrative example: a change after closing
In a fictional eight-hour closed period, a compressor records 22 minutes of running on one evening and 71 minutes on another. Both periods have complete data. The second evening also includes a planned equipment wash. The supervisor checks when the wash ended before deciding whether the remaining run time needs investigation. A separate evening with an offline logger is marked incomplete and left out of the comparison.
The review might lead to checking the schedule, a downstream air use or the compressor’s operating settings with the responsible technician. Those possibilities are questions to investigate. The minutes alone do not establish a leak, savings, or a failing component.
Prove the first installation before adding assets
Compare a monitored start and stop with the controller indication or a witnessed cycle. Interrupt connectivity in an approved test and verify that the record distinguishes a gap from a stopped machine. If the device buffers events, verify that restored records keep their original times and do not duplicate the totals. Agree who reviews the data and what they will do when it changes.
See equipment monitoring for planning a first installation, or embedded systems for equipment monitoring when a packaged monitor cannot capture the right signal.