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Unformatted text preview: is a dimensionless
number between 0 and 1 and is defined as the ratio of the real power flowing to the load to the
apparent power in the circuit. Usually, p, or the power factor, is not included on the label. Based on
measurement of a variety of equipment in the facility, however, we assume for simplicity that when
we need to estimate p, inductive loads (motors, pumps etc.) have p = 0.75, resistive loads (heating
elements) have p = 1, and older computerized test equipment have p = 0.6. For a three phase circuit, which most of the large industrial equipment in the IADC operates on,
the equation becomes
3 Preal = \/5(
i=1 VIp (4.2) where i indexes each phase.
While this method is fast and inexpensive, there are significant drawbacks stemming from the
fact that the label only indicates maximum power draw rather than a profile of energy use over
different operational modes. Occasionally, this information may be furnished by other equipment
documentation or manufacturer support, though based on experience the likelihood of those resources
existing tends to decline with the age of the equipment. In general, experience sug...
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This document was uploaded on 03/03/2014 for the course ADMIN 1 at Universidad Nacional de Colombia.
- Spring '14