Monitoring motor production in HVAC units, air chillers, air compressors, wind turbines or
anything generated by a motor is the easiest way to reduce energy consumption. The EPA did
a Best Management Practices for Colleges and Universities study utilizing sub-
meters to monitor and manage energy consumption and the ROI on any one project was a
year or less*. Gathering data for a manufacturing site utilizing the same equipment is no
It is problematic to monitor energy consumption on a whole, as identifying the specific
equipment causing issues will be difficult. But what if you could affordably and
efficiently monitor all the major machines, air compressors and individual production
site? This would allow facility managers the ability to cut cost in a simple, effective and
For this reason Davidge Controls has produced a meter that can communicate via RS-232
or RS-485, using Modbus or our own simplified protocol. Besides tracking kilowatt hour
usage, the meter has a program capable of logging volts, amps, watts, power factor, phase
angle and frequency per phase that can be exported to Microsoft Excel or similar
programs. Analysis of this data not only reveals leakage on a day-by-day basis, but over
time, reveals pending motor failures. Energy monitoring of your motors can reduce
maintenance and operating costs significantly.
By monitoring the real power consumed and apparent power by a compressor motor over
time, the changes in the efficiency of the unit will become graphically apparent over
a short period of time if and as problems develop.
Problems with bearings will show as a numerical decrease in the power-factor value of
the unit, because of the increasing drag (and power consumption) on the motor. This
wasted energy is dissipated as heat, which also speeds up the time to failure. By
monitoring the power-factor of the motor at regular intervals (i.e. once a day to once a
week), a trend can be developed to show a future failure. This will give the opportunity
to fix the situation at your convenience before the failure actually occurs, and minimize
the down-time and inherent costs of a catastrophic failure.
Monitoring motor power consumption of the unit or the on/off cycling ratio correlated to the
required loading (temperature or time usage), can show loss of refrigerant (in
refrigeration systems) or leaking tanks and/or delivery systems in compressed air or gas
systems. Preventive maintenance can reduce the continued overhead cost of energy
required for these systems.
Repairing a single motor instead of having to replace it can pay for the entire cost of the
monitoring system. Monitoring motor usage on a regular basis and reducing consumption is not
only good for the environment and company image, but also can lead to rebates and
potential energy star rating.
With energy cost on a constant rise and a nation pushing to reduce consumption and
minimize industry’s carbon footprint, managing energy usage in all facets of production
is the responsible way to improve the future. The ability to manage this affordably,
effectively, and efficiently only increases the bottom line!
Any questions or concerns regarding this article can be sent to Ryan Fetgatter, General
Manager Davidge Controls, 583 N Refugio Rd Santa Ynez, CA 93460
Toll Free 800-824-9696, Phone 805-688-969 or email ryan [at] ezmeter.com.