Wright Engineering Corporation

165 East Chilton
Chandler, Arizona 85225

RE: Western Watt, Inc.

Dear Tom

I have reviewed the articles submitted to me by Western watt as requested.

In the article titled “How Often Do Transients Occur?” by Walton N. Hershfield. P.E., he explains how transient activity lowers the efficiency of induction motors and increases power consumption accordingly. The basic cause of the increased power consumption is as follows:

Transient energy created by switching of induction loads such as motors, transformers and lighting must be dissipated in the electrical system. The majority of this energy is dissipated in the Iron core of inductee devices connected to the line such as motors. “As the transient energy is dissipated in the inductive device, it causes a decrease in its operational efficiency and increases power consumption. This decrease in efficiency occurs because the natural oscillatory frequency (fɱ) of the transient is more than 10 times the primary frequency f1 (60Hz) at which the device was designed to operate. As a result the transient oscillatory perturbations act on the outer magnetic domains of the iron-core sheets to prevent the working magnetic field at line frequency f2 from penetrating the core.”

These transient spikes can vary from only a few per hour in a small office or home to over 430,000 in a large industrial plant. These transient surges are especially heavy in a plant where motors are switched on and off regularly as part of the plant operation.

Another area of high transients is in a facility where solid-state starters and variable frequency drives are used. Unless this state of the art equipment is filtered and isolated from the plant electrical system, many problems can occur to computers and computer driven process equipment.

The system is a device that filters out the transient spikes from an electrical system. With the elimination of these electrical transients, motors on the line can run more efficiently and thus use less power.

The amount of savings depends on the size and frequency of transient interference. In his article titled, “Testing and Selecting Surge Suppressors for Low-Voltage AC Circuits”, Mr. W. J. Lee estimates that in a heavy industrial plant, power loss due to transient interference can be as high as 20% above the normal power consumption without transients. in a low transient atmosphere these losses may be only 2%.

The elimination of these transients will not only protect voltage sensitive equipment such as computers, but will also improve the efficiency of motors thus reducing power consumption.

Sincerely yours

Ronald S. Wright, P.E.

The Original Letter:

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