January 2013 Electrical Apparatus

January 2013 Electrical Apparatus

This is a summary of the Electrical Apparatus January 2013 featured technical article,  by Richard L. Nailen, P.E.   

The world of electrical and electronics technology is crowded with acronyms and abbreviations. Some are familiar to everyone:–a-c and d-c, HDTV, DVD, AM/FM, LED, LCD–but others are less widely used, and some are outright misleading.

AIC, for amperes interrupting capacity, is sometimes defined, erroneously, as asymmetrical interrupting capability. BIL, or basic impulse level, is often applied to motors or generators, but no machinery standard recognizes the usage.

DOL/ATL, which stands for direct onlne/across the line, is often used in reference to motor starting, but the term makes clear only that the user intends to apply line voltage directly to the motor. It refers to no particular value.

A BLDC is commonly understood to be a brushless d-c motor, but the acronym fails to indicate which of two types of brushless d-c motors. The difference matters.

EMF is widely understood to refer to electromotive force, but that meaning is somewhat dated, and today EMF might just as easily mean electromagnetic field.

UHV means ultra-high-voltage, right? Yes, but the lower threshold of that range will vary depending on where you are. U.S. definitions differ from those in Europe.

And don’t confuse the NEC, for National Electrical Code, with the NESC, for the National Electrical Safety Code. The former is a standard of the National Fire Protection Association, while the latter is not.

Some think that PD, or partial discharge, is another term for corona. They are wrong. The partial electrostatic breakdown of air leads to the aura, or “crown,” seen on conductors subject to high surface voltage gradients, but the two phenomena are not the same.

PFC, in electro-speak, is not a U.S. Army private first-class. It is either power factor correction or a power factor controller–each of which, it turns out, is misleading in its own way.

Another acronym with dual meanings is SCR, which can mean either silicon-controlled rectifier or short-circuit ratio. Avoid ambiguity. When in doubt, spell it out.

Yet another ambiguous acronym is SRM. Is it a synchronous reluctance motor or a switched reluctance motor? To be on the safe side, be specific.

These are only some of the initializations and acronyms common in electrical and electronics parlance. A number of others are explained in the January 2013 EA article.

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