The Electrical Code

I will make the language they use in the code book easier to read and then the actual words the code book uses after in italics. I hope this helps the reader understand the code better.

90.1 Purpose.

(A) Practical Safeguarding. Let’s start with the first paragraph on page 70-29 of the 2020 code book. 90.1(A), all its saying is that it seeks to protect people and our property from the dangers of electrical hazard. That’s it, it might sound complicated but that’s it.

“The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity. This Code is not intended as a
design specification or an instruction manual for untrained persons.”

(B) Adequacy. Refers to placing equipment so that it can be properly maintained. In other words an inspector can fail you because you can’t get to something as simple as a 1900 box. They used very complicated words in this part that frankly did not need to be this way but i guess they love to use different words to expand their vocabulary.

“This Code contains provisions that are considered necessary for safety. compliance therewith and proper maintenance result in an installation that is essentially free from hazard but not necessarily efficient, convenient, or
adequate for good service or future expansion of electrical use.”

(C) Relation to Other International Standards. So this part of the code is referencing another body that writes standards and it says that it is similar to it. I believe that wanted to cover that standard so that if it missed anything it can say it referred to how similar it is to that standard.

“The requirements in this Code address the fundamental principles of
protection for safety contained in Section 131 of International
Electrotechnical Commission Standard 60364-1, Electrical Instal‐
lations of Buildings”

90.2 Scope.

(A) Covered. This refers to the installation and removal of the equipment(which means anything that electricity runs through it), the communication wires to or from it, and the means(raceway, conduits, etc.) electrical runs to the equipment.

“This Code covers the installation and removal of
electrical conductors, equipment, and raceways; signaling and
communications conductors, equipment, and raceways; and
optical fiber cables and raceways.”

(1) Describes the location,

“Public and private premises, including buildings, structures, mobile homes, recreational vehicles, and floating buildings.”

(2) This describes open locations,

“Yards, lots, parking lots, carnivals, and industrial substations.”

(3) This describes anything that runs off of electricity,

“Installations of conductors and equipment that connect to the supply of electricity”

(4) OH this one goes after the utility, which I have never seen an inspector at after a substation is open for business, even there shadow.

“Installations used by the electric utility, such as office buildings, warehouses, garages, machine shops, and recreational buildings, that are not an integral part of a generating plant, substation, or control center”

(5) (5 is new for 2020 code book.) Has to do with marine vessels, and something interesting called leakage current which I will go through more after this.

(6) (6 is new to for 2020 code book.) So to bring power from any type of vehicle(if you live in the middle of no where and the utility can’t get to you then you bring power from you car. This is usually done by means of an inverter or even if you wire the house to use 12 volts DC this describes the installation and removal.

(B) Not covered is pretty self explanatory right what the code did not want to be responsible for.

(1) Not shore power but how ships are wired,

“Installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles.”

(2) Not how the power gets to the mines but how the mines use the power they don’t give a rats ass what they do,

“Installations underground in mines and self-propelled mobile surface mining machinery and its attendant electrical trailing cable.”

(3) Trains signal and communications,

“Installations of railways for generation, transformation, transmission, energy storage, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signaling and communications
purposes.”

(4) Last but not least the communications for utility they don’t want to nothing about. Part five refers to installation of utilities

“Installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations.”

(5) This section describes how when an electrical contractor works directly with the public utility the following circumstance the code book does not cover:

“Installations under the exclusive control of an electric
utility where such installations.”

a. Service drops, and metering. b. Refers to property that is leased, owed by the utility. c. Same langue but it refers to easements or right-of-way which is in a property contract deed. d. Native American reservations, U.S. Department of the Interior Bureau of Indian Affairs, Military bases, Land controlled of Indian Affairs, Land controlled by port authority and state agency and departments, and land owned by railroads. This covers pretty much every other area of the country.

(C) Special Permission. This C-section grants the authority having jurisdiction has the right to alter the decision of the NFPA. It does not say it in those words but it pretty much says that.

90.3 Code Arrangement. The code has an introductory chapter, and nine chapters, chapter 1, 2, 3, and 4 are general requirements. Chapters 5, 6, and 7 special requirements. Chapter 8 is communication. Chapter 9 deals with tables. The first three chapters are the back bone of the book.

“This Code is divided into the intro‐ duction and nine chapters, as shown in Figure 90.3. Chapters 1, 2, 3, and 4 apply generally. Chapters 5, 6, and 7 apply to special occupancies, special equipment, or other special conditions supplement or modify the requirements in Chapters 1 . Chapter 8 covers communications systems and is not subject to the requirements of Chapters 1 through 7 except where the requirements are specifically referenced in Chapter 8. Chapter 9 consists of tables that are applicable as referenced. Informative annexes are not part of the requirements of this Code but are included for informational purposes only.”

90.4 Enforcement To make enforcement possible rules need to be written down, when written down they need to be legible to the public, the code does this well but they do leave room for interpretation. So the book will say something like the authority having jurisdiction has the final word and its left to them to interpret the code. The authority having jurisdiction also can wave code requirements.

“This Code is intended to be suitable for mandatory application by governmental bodies that exercise legal jurisdiction over electrical installations, including signaling and communications systems, and for use by insurance inspectors. The authority having jurisdiction for enforcement of the Code has the responsibility for making interpretations of the rules, for deciding on the approval of equipment and materials, and for granting the special permission contemplated in a number of the rules.

By special permission, the authority having jurisdiction may waive specific requirements in this Code or permit alternative methods where it is assured that equivalent objectives can be achieved by establishing and maintaining effective safety.

This Code may require new products, constructions, or materials that may not yet be available at the time the Code is adopted. In such event, the authority having jurisdiction may permit the use of the products, constructions, or materials that comply with the most recent previous edition of this Code adopted by the jurisdiction.“

90.5 Mandatory rules, Permissive rules, and Explanatory Material.

(A) Mandatory rules. These are the rules that show action that are prohibited or required and are seen as using terms as shall or shall not.

“Mandatory rules of this standard are those that identify actions that are specifically required or prohibited and are characterized by the use of the terms
shall or shall not.”

(B) Permissive Rules. These rules of the code are rules that are allowed but not required. and then the rule goes further to explain that the rule normally used to give the reader options or better said an alternative way of the build. The langue is used to give the reader information on the shall or the shall not.

“Permissive rules of this standard are those that identify actions that are allowed but not required, are normally used to describe options or alternative methods, and are characterized by the use of the terms shall be permitted or shall not be required.”

(C) Explanatory Material. This is an interesting one. This deals with referencing material other then the code. When we do that the code does not recognize it. The second paragraph indicates that when thing are in brackets they are referenced for information purposes only and are provided as a guide. crazy that even when they reference there own information they do not try to allow you to see it as a rule.

“Explanatory material, such as references to other standards, references to related sections of this standard, or information related to a Code rule, is included in this standard in the form of informational notes. Such notes are informational only and are not enforceable as requirements of this standard. [ROP-13] Brackets containing section references to another NFPA document are for informational purposes only and are provided as a guide to indicate the source of the extracted text. These bracketed references immediately follow the extracted text.
Informational Note: The format and language used in this standard follow guidelines established by NFPA and published in the NEC Style Manual. Copies of this manual can be obtained from NFPA.”

(D) Informative Annexes. These are not enforceable by the code, but rather they try to add information to what we can understand as rules.

“Non-mandatory information relative to the use of the NEC is provided in informative annexes. Informative annexes are not part of the enforceable require‐ ments of the NEC, but are included for information purposes only.”

90.6 Formal Interpretations. This is to give uniformity to the code so they can seem as if they are talking the same language article after article.

“To promote uniformity of
interpretation and application of the provisions of this standard, formal interpretation procedures have been established and are found in the NFPA Regulations Governing
Committee Projects.”

90.7 Examination of Equipment for Safety.

I needed to look up what “promulgation” meant. And what is meant is “The act of making a law or decree known, or formally putting it into effect, by public declaration.” For this section what we need to know is that when using equipment and material we need to check when using that it is in good working condition and we are not testing the limits to the standard the company has set for products we use. And then goes to say that the code helps us by not having several companies do testing. It sounds to me that they did not want to have several companies test there products. And in doing so the code holds us and the final inspection to make sure everything is on good working order. This is my opinion or better said it is my interpretation of what I have read.

“For specific items of equipment and materials referred to in this Code, examinations for safety made under standard conditions provide a basis for approval where the record is made generally available through promulgation by organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service-value determination through field inspections. This avoids the necessity for repetition of examinations by different examiners, frequently with inade‐ quate facilities for such work, and the confusion that would result from conflicting reports on the suitability of devices and materials examined for a given purpose.
It is the intent of this Code that factory-installed internal wiring or the construction of equipment need not be inspected at the time of installation of the equipment, except to detect alterations or damage, if the equipment has been listed by a qualified electrical testing laboratory that is recognized as having the facilities described in the preceding paragraph and that requires suitability for installation in accordance with this Code.”

90.8 Wiring planning.

(A) Future Expansion and Convenience. This allows us to increase the size or run an extra pipe when initially installing equipment for future expansion.

“Plans and specifications that provide ample space in raceways, spare raceways, and additional spaces allow for future increases in electric power and communications circuits. Distribution centers located in readily accessible locations provide convenience and safety of operation.”

(B) Number of Circuits in Enclosures. This is trying to protect circuits from exposure to arching. Pretty simple.

“It is elsewhere provided in this Code that the number of circuits confined in a single enclosure be varyingly restricted. Limiting the number of circuits in a single enclosure minimizes the effects from a short circuit or ground fault.”

90.9 Units of measurement.

(A) Measurement System of Preference. This tells us that the code uses the metric units of measurement.

“For the purpose of this Code, metric units of measurement are in accordance with the modernized metric system known as the International System of Units (SI).”

(B) Dual System of Units. This says that the code shall give us the metic measurement then in parentheses inch-pounds following there after. Pretty self explanatory.

“SI units shall appear first, and inch-pound units shall immediately follow in parentheses. Conver‐ sion from inch-pound units to SI units shall be based on hard conversion except as provided in 90.9(C).”

(C) Permitted Uses of Soft Conversion. Talk about being annal, because metric units convert to inches with fraction the code does not want to show this and will only give the rounded off measurement.

“The cases given in 90.9(C)(1) through (C)(4) shall not be required to use hard conversion and shall be permitted to use soft conversion.”
(1) Trade Sizes. This is important to know, they will give us trade sizes going forward. I guess they did not want to go through the hassle of converting that to.

“Where the actual measured size of a product is not the same as the nominal size, trade size designators shall be used rather than dimensions. Trade practices shall be followed in all cases.”
(2) Extracted Material. They try not to alter what the original standard says.

“Where material is extracted from another standard, the context of the original material shall not be compromised or violated. Any editing of the extracted text shall be confined to making the style consistent with that of the NEC.”
(3) Industry Practice. Again they did not want to do conversion when they did not need to.

“Where industry practice is to express units in inch-pound units, the inclusion of SI units shall not be required.”
(4) Safety. This is covering there ass when conversions need to be made.

“Where a negative impact on safety would result, soft conversion shall be used.”
(D) Compliance. I guess we need to use the google conversion calculator because they don’t want to use decimal points.

“Conversion from inch-pound units to SI units shall be permitted to be an approximate conversion. Compliance with the numbers shown in either the SI system or the inch-pound system shall constitute compliance with this Code.”

In Article 90 in general want to give us the ground rules for the code book. And it also tells us how to read it when conversions don’t have decimal points.