4 FM quick reads on Motors
1. How to Catalog and Analyze Motors and Drives
Managers can use computerized maintenance management systems (CMMS) to catalog and analyze motors and drives by treating them as parts of a three-component system: the equipment the system drives, the drive itself, and the motor. One example would be a specific air supply or exhaust blower connected to a motor by a V-belt drive that transfers power and adjusts speed. It would consist of a sheave mounted on the motor shaft and a sheave mounted on the blower shaft.
Managers can use these steps to more efficiently catalog and analyze motors and drives:
- Fill in all the fields in the CMMS equipment-record template at the time of installation or replacement.
- Create reason codes — such as broken part, corrosion, or operator error — and action codes — which can include cleaned part, replaced part, and adjusted part — in the work-order set-up for further root-cause analysis.
- Use written work orders for emergencies, routine repairs, and preventive maintenance and predictive maintenance activities. Record completed work, labor and materials included in the job, and reason and action codes, where applicable. Most CMMS automatically transfer work-order data to the equipment history when the technician closes the work order.
- Analyze the collected data, including mean time between failures, mean time to repair, and root-cause analysis, to determine the cause of the failure. Was it corrosion, wear, heat, operator error, or another cause? The data, along with energy costs, form the basis for decisions on continuous improvement, repair or replacement, and comparison of alternatives to motors and drives.
4. Replace Oversized Motors To Reduce HVAC Energy Use
Today's tip from Building Operating Management comes from James Piper, contributing editor to Building Operating Management and Maintenance Solutions magazines: Replace oversize motors to reduce HVAC energy use.
Commercial and institutional facilities typically have many more motors operating in their HVAC systems than most managers realize. Because these motors use so much energy, they offer great opportunities to make a significant impact on facility energy use.
By far the leading cause of energy inefficiency with HVAC system motors is a mismatch between the motor's rated horsepower and the load it is driving. Most HVAC system motors are induction motors.
While these motors are efficient and reliable, their efficiency, like building chillers, drops off significantly when they operate under part-load conditions. By properly matching motor horsepower to system load requirements, managers can achieve major energy savings.
Achieving this goal requires that managers conduct a survey on HVAC system motors to identify those that are significantly oversized for the application. The goal of the process is to develop a comprehensive list of applications that use motors, including information on the motor horsepower, the load it is driving, and the age and rated efficiency of the motor.
The focus should be on motors that are oversized or have exceeded their operating life expectancies.
Replacing older, oversized motors with properly sized ones offers two benefits. First, matching the motor horsepower to the actual load improves the operating efficiency of the system.
Second, changes in motor design have resulted in a generation of motors that have operating efficiencies 2-8 percent higher than older, standard motors. Coupled with the improved operating efficiency that comes from matching the motor horsepower to the load, the improvement in efficiency can provide a relatively quick payback for managers and facilities.
This has been a Building Operating Management Tip of the Day. Thanks for listening.