IESO - Industrial Electric System Operation

Who Should Attend?
What Does the IESO Class Cover?

Who Should Attend?
The Industrial Electrical System Operation (IESO) is a 3-day class. It was developed in 1979 specifically for purchasing professionals in industrial and large commercial environments. The purchasing professionals who attended the class returned to their jobs and began discussing the electrical world in such depth that electricians, building engineers, and plant engineers began to attend. The class is now also directed at these three groups, although groups such as millwrights that work around electrical equipment will also benefit.

The IESO class is only available on an in-house basis. These in-house classes are typically offered through groups such as purchasing associations, mechanical engineering associations and the building owners and managers associations.

What Does the IESO Class Cover?
The IESO class assumes no electrical background, and builds on the basics to provide a comprehensive understanding of the equipment and operations. It covers generation thoroughly for two reasons.

One is that many businesses have generation. The second is that motors and generators are the same.

Understanding the basics of generators results in understanding motors, and motors are 60% of the total electrical load in the U.S. Transmission in an electric utility system is briefly discussed and then the utility distribution is covered in detail. This is because all customers connect directly to either the transmission system or distribution system. The operations of these two systems directly affect the operation and reliability of all customers. Another key reason for describing the distribution system in detail is that the various electrical services provided by an electric utility (single-phase120/240, and 3-phase systems that include 120/240 delta, 120/240 open delta, 208Y/120, and 480Y/277) are the same systems found inside commercial and industrial facilities.

IESO covers the principles behind selecting a service including the advantages, disadvantages and limitations of each of the services. In the open delta system, the wild leg (also called the power leg, the bastard leg, the stinger, and the high leg) is described including the danger it poses to customer equipment. The reliability aspects regarding transformer connections include open neutrals that result in high voltages that destroy electronics, and stray voltages associated with bad connections and with bad grounding.

The key billings components including energy, demand and power factor are thoroughly discussed, along with time-of-use and real-time pricing.

All commerical/industrial voltages are derived from transformers. The theory behind transformer operation is covered followed by a detailed description of transformers. This part of the IESO class clearly answers the number one questions asked by electricians in the class, "Why is it that when I connect a piece of copper between two phases, it instantly vaporizes, but when I put loops into the same wire and connect it the same, nothing happens?"

Circuit breakers and protective relays are covered. Substation breakers are covered for industrial plants that own substations. Medium voltage breakers are covered with emphasis on metalclad circuit breakers including air-magnetic, vacuum and SF 6. Low voltage 480-volt metalclad circuit breakers are described with emphasis on the difference on series and shunt trip coils. Special emphasis is placed on the criteria area of fault current analysis and sizing the circuit breaker for maximum fault current.

The various types of fuses are discussed and followed by a discussion on how fuses are used in conjunction with circuit breakers. The basics of coordination studies and coordinating protective devices are presented in a manner designed to provide the student with the background necessary to use the various PC-based software packages for performing coordination studies.

Once the equipment on the utility side of the meter is covered, the class moves to the customer side of the meter. The basics of motors and motors controls are a key part of this portion of the class. Induction, synchronous and DC motors are described. The various types of motor controls are an integral part of the class. Emphasis is placed on variable frequency drives and why their numbers are growing so rapidly.

Reliability issues are presented in terms of causes, remedies and preventative measures. Harmonics are a major component of this part of the class including causes, effects on electrical systems, and solutions. This part of the class explains why specifying a k-factor when ordering a transformer is so critical.

A portion of the class tackles the least understood part of electrical operations, reactive power which is also described as power factor. Reactive power is clearly described including its unit of measure, VArs. The negative impact of VArs on a utility's finances is used to illustrate why customers are charged for excessive VArs. The use of capacitors is described showing in a simple way exactly how they correct power factor. This explanation is done with math, without vectors and without the power triangle in a way that everyone understands. A brief discussions then brings math into the class as the power triangle is described.

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