Switching PM gears for fast and furious maintenance

CMMS conventional wisdom tells us to schedule our machine preventive maintenance items on a calendar, but what if it's too early to check and replace a part?


CMMS conventional wisdom tells us to schedule our machine preventive maintenance (PM) items on a calendar just like we do for our car tune-ups. It's been 90 days, so it must be time to re-calibrate the auger in the extruder, or replace the impeller on a centrifugal pump. But what if it's too early to check and replace a part?

While being reactive and waiting to make repairs only after equipment fails hurts productivity, changing parts before the end of their run is also a waste of time and money. If you're doing too many PMs based on a calendar and you're wasting precious maintenance resources to do the work, you may want to consider more efficient options. To preserve equipment and ensure plant floor machines are fully operational and reliable, safe, and long-lasting, consider more proactive PMs.

PMs come in many shapes and sizes. Meter readings offer greater PM intelligence. Let's say a piece of equipment has fallen below the acceptable performance threshold, slowing down production and reducing output. Meter trending may show that widget output falls after 600 hrs of continued use, which may exceed the manufacturer's recommendation for replacing components. Meter readings to periodically check production volumes and perform the necessary maintenance tasks trump calendar-based PMs, which remain static as production volumes change over time. And you risk scheduling too few or too frequent PMs that won't parallel the growth of the company.

Another useful PM, condition-based maintenance (CBM), is based on the health of your asset. CMB-based PMs can prevent degradation of components in the equipment. CBM incorporates real-time data about machine health so that maintenance work can be done when it is actually necessary—and not according to a rigid calendar schedule. Monitoring machine health by controlling oil corrosion with a PM to change filters prevents failures.

Checking oil levels, contaminants, temperatures, vibration levels, (among others) all fall under CBMs. A civil engineering company that manages wastewater treatment plants has to regularly test conditions of its centrifugal blowers for alignment, temperatures, vibrations, etc. Each blower has a gearbox with an oil capacity of 27 gal. CBM tests allowed the maintenance team to analyze lab results for detecting metal in the oil, resulting in less frequent oil changes—and lower maintenance costs.

This way the condition of the equipment drives the schedule—not the calendar.

Read more articles by Paul on his blog, Lachance on CMMS.

No comments
Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
Salary survey: How much are you worth?; Dedicated outdoor air systems; Energy models and lighting
Fire, life safety in schools; Fire protection codes; Detection, suppression, and notification; 2015 Commissioning Giants; Emergency and standby power in hospitals
HVAC and building envelope: Efficient, effective systems; Designing fire sprinkler systems; Wireless controls in buildings; 2015 Product of the Year winners
Designing positive-energy buildings; Ensuring power quality; Complying with NFPA 110; Minimizing arc flash hazards
Implementing microgrids: Controlling campus power generation; Understanding cogeneration systems; Evaluating UPS system efficiency; Driving data center PUE, efficiency
Optimizing genset sizing; How the Internet of Things affects the data center; Increasing transformer efficiency; Standby vs. emergency power in mission critical facilities
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.