by Gerald Newton

Ladies and Gentlemen, the Utility Power House Sacred Cow is under attack by respectable and responsible electrical do-gooders. Sorry, old timers, your years' old mandates on who does what for whatever reason are under attack by a new generation of more educated and able professionals. Now what about all that utilization equipment that you think utility companies can install in power houses without any rules? Give us a break! The National Electrical Safety Code is a bare bones code. It is designed that way. Right! So utility electrical engineers can go about their merry way building and designing as they please, using the National Electrical Code as a guide only. Power House mentality, that's what some call it. Oh yes, they say to Inside Journeyman Wireman, "We are exempt from the NEC." "No conduit fill requirements for us." "No cable tray fill requirements, either." "By George! We can even run a No. 12 AWG in cable tray if we want to." "We can fill a conduit as full as our NEC Code doubting hearts desire." "And, after we overfill it we will support it any way we want to." That's right, partners -- Because the National Electrical Safety Code does not contain specific requirements, the utility companies have had their own pre-Madonna special treatment, and don't think you are going to crash it. But wait, this is 1995 and...Sorry utility folks, you are under the gun. You either comply with the NEC or face the strong possibility of getting your utility company, contractor, and design engineers sued to heck and back! So here are the pitiful details.

Power plant electrical utilization systems include the lighting loads, receptacles, heating and ventilating equipment, welding receptacles, overhead cranes, and any other system directly or not directly associated with the generation, communications, metering, control, transformation, transmission, and distribution of electric energy by the utility. These utilization systems exist in Power Generation Buildings that are used exclusively by the utility in charge, and that is what this article is all about -- the utilization systems that are in utility-function-only buildings, not offices, warehouses, and recreational buildings.

Basic Differences Between the NEC and NESC

The NESC's purpose is different from the NEC. While the NEC is written and adopted for the practical safeguarding of property and persons, the NESC is written and adopted for the practical safeguarding of only persons from the hazards arising from the use of electricity. Additionally, there are basic philosophical differences in the two documents. The NEC is, as many engineers describe, a "cookbook" of design rules specifying the minimum standards on how safe installations must be accomplished, while the NESC is a performance standard that specifies what is to be performed, not how it is to be accomplished, leaving that part to the engineers. The NEC contains thousands of requirements not found in the NESC and is primarily a new construction safety standard for premise wiring systems. The NESC is primarily a safety standard for outside utility owned systems and applies to new construction and to existing systems. However, the two codes have some overlapping requirements. For example, both Codes have requirements for service drop clearances, and both Codes refer to the other for additional information. Unlike the NEC, the NESC contains an entire Part 4 dedicated to work rules for employees.

Some examples of the differences between the two codes is how the requirements are stated. For example, the NESC does not contain specific rules for supporting raceways and boxes. Instead the requirements are given in Rule 110 C that states: "All stationary equipment shall be supported and secured in a manner consistent with reasonably expected conditions of service." Instead of rules like those found in Articles 240 and 310 of the NEC, the requirements for conductors and overcurrent protection are given in rule 161 that states: "Conductors and insulation shall be protected against heating by the design of the system and by overcurrent, alarm, indication, or trip devices."

What does the NEC say about utilization wiring in power plant buildings?

The NEC does not specifically state that utilization equipment and wiring in Power Houses are not covered, but many authorities and a Code Making Panel for the 1987 Code have interpreted 90-2(b)(5) to mean that the NEC does not cover utilization equipment in power plant buildings or in any other location used exclusively by the utility. Per 90-2(b)(5), the National Electrical Code does not cover "installations under the exclusive control of electric utilities for the purpose of communications or metering; for generation, control, transformation, and distribution of electric energy located in buildings used exclusively by the utilities for such purposes or located outdoors on property owned or leased by the utility or on public highways, streets, road, etc., or outdoors by established rights on private property."

What does the NESC say about utilization wiring in power plant buildings?

The National Electrical Safety Code does not cover utilization equipment except as covered in Part 1 and Part 3. The scope for Part 1 of the NESC does include power plant utilization wiring that is used by the utility in the exercise of its function as a utility.

What does Part 1 of the NESC say?

Part 1 of the NESC contains rules for the installation and maintenance of electric supply stations and equipment. An electric supply station is defined in Section 2 of the NESC as "Any building, room, or separate space within which electric supply equipment is located and the interior of which is accessible, as a rule, only to qualified persons. This includes generating stations and substations, including their associated generator, storage battery, transformer, and switchgear rooms or enclosures but does not include facilities such as pad-mounted equipment and installations in manholes and vaults."

The Scope of Part 1 states "Part 1 of this code covers the electric supply conductors and equipment, along with the associated structural arrangements in electric supply stations, that are accessible only to qualified personnel. It also covers the conductors and equipment employed primarily for the utilization of electric power when such conductors and equipment are used by the utility in the exercise of its function as a utility." There are rules in Part 1 of the NESC for utilization equipment including storage batteries, rotating equipment, transformers and regulators, conductors, circuit breakers, switches, fuses, reclosers, switchgear, metal-enclosed bus, and surge arresters.

Rule 127 in Part 1 for Classified locations states, "Electrical installations in classified areas shall meet the requirements of ANSI/NFPA 70-1993, Articles 500 through 517." This is the only place that the NEC is referenced as being a mandatory requirement in Part 1 of the NESC.

What Does Part 3 of the NESC say?

Part 3 of the NESC contains rules for the practical safeguarding of persons during the installation, operation, or maintenance of underground or buried supply and communication cables and associated equipment. Part 3 also does not contain all the same rules or nearly the number of rules as found in the NEC.

Does the NESC require that the NEC be used where there are no rules in the NESC for installations that have rules in the NEC?

The NESC has a general rule 012 C in the introduction that states, "For all particulars not specified in these rules, construction and maintenance should be done in accordance with accepted good practice for the given local conditions." Section 3 of the NESC contains a list of accepted good practices, including the NEC. Additionally, in his discussions about the NESC in his Video Tape Series, Allan Clapp states that "should" in a court of law means "shall when practical." Practical means that there is no intention of requiring or even recommending more expensive construction than good practice requires and good business justifies to achieve a safe installation as opposed to doing everything possible or practicable to achieve safety. Since the NEC is a practical safeguarding standard for new construction, professional responsibility requires that the construction of new power plants be performed in accordance with the NESC and the NEC, whichever is more stringent, where the NESC and the NEC have been adopted as the local minimum safety standards.

Conclusion: Responsible professionals install utilization wiring in power plants to meet the minimum standards of the NEC and the NESC.

There are no concrete rules in the NEC or NESC to make the NEC the minimum standard for the utilization wiring in a power plant. However, if an accident occurs a jury may determine that it is the responsibility of the design engineers, the persons making the installation, and the operating utility to insure that, in addition to the NESC, an industry accepted standard such as the NEC should, when practical, be a minimum safety standard for the utilization wiring. It would be difficult, indeed, for those responsible for the installation to convince a jury that they were not cognizant of the National Electrical Code and the implications and consequences of not using it as a minimum safety standard. Those responsible might be granted some relief if they can prove that compliance to all minimum requirements in both the NESC and the NEC is cost prohibitive and impractical. However, there seems to be no excuse whatsoever for noncompliance where it can be shown that the cost for compliance is equal to or less than noncompliance. When considering that trained and qualified electricians, supervisors, and engineers are more motivated and efficient when doing work according to the NEC, it appears impractical, irrational, and more expensive to retrain them to install substandard electrical work not in compliance. The bottom line is: Install utilization system wiring in Power Plant Buildings to meet the minimum standards in the NESC and the NEC, whichever is more stringent, or suffer the consequences.