The Electrical Code

This is Part 1 of article 110.This article will split into a couple of blogs due to its importance and its length. They are all important I almost for got to say but I feel we get a lot out of this article. Enjoy!!!!

Part I. General – This article lets us know how things are going to be done so that the power of electricity can be safe to use in any type environment safely under the rules of the code.

“110.1 Scope. This article covers general requirements for the examination and approval, installation and use, access to and spaces about electrical conductors and equipment; enclosures intended for personnel entry; and tunnel installations.
Informational Note: See Informative Annex J for information regarding ADA accessibility design.”

So when we are the field we tend to work with what we bought. The code and inspectors(if it is getting inspected) don’t care if you just figured out how to run the power a better way then what you have the material for and try to make it work with what you got. You need to make sure you run the electrical power correctly, no short cuts.

“110.2 Approval. The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
Informational Note: See 90.7, Examination of Equipment for Safety, and 110.3, Examination, Identification, Installation, and Use of Equipment. See definitions of Approved, Identified, Labeled, and Listed.”

110.3 Examination, Identification, Installation, Use, and Listing (Product Certification) of Equipment. All equipment that needs electrical power has a label that tells us how many watts, volts, resistance the equipment needs in electrical power. This is usually a underwriters laboratory company that certifies this information.
“(A) Examination. In judging equipment, considerations such as the following shall be evaluated:
(1) Suitability for installation and use in conformity with the provisions of this Code Informational Note No. 1: Equipment may be new, reconditioned, refurbished, or remanufactured.

Informational Note No. 2: Suitability of equipment use may be identified by a description marked on or provided with a product to identify the suitability of the product for a specific purpose, environment, or application. Special conditions of use or other limitations and other pertinent information may be marked on the equipment, included in the product instructions, or included in the appropriate listing and labeling information. Suitability of equipment may be evidenced by listing or labeling.
(2) Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided
(3) Wire-bending and connection space
(4) Electrical insulation
(5) Heating effects under normal conditions of use and also under abnormal conditions likely to arise in service

(6) Arcing effects
(7) Classification by type, size, voltage, current capacity, and specific use
(8) Other factors that contribute to the practical safeguarding of persons using or likely to come in contact with the equipment (B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
N (C) Listing. Product testing, evaluation, and listing (product certification) shall be performed by recognized qualified electrical testing laboratories and shall be in accordance with applicable product standards recognized as achieving equivalent and effective safety for equipment installed to comply with this Code.
Informational Note: The Occupational Safety and Health Administration (OSHA) recognizes qualified electrical testing laboratories that perform evaluations, testing, and certification of certain products to ensure that they meet the requirements of both the construction and general industry OSHA electrical standards. If the listing (product certification) is done under a qualified electrical testing laboratory program, this listing mark signifies that the tested and certified product complies with the requirements of one or more appropriate product safety test standards.”

110.4 Voltages. Voltage, what a device needs to work properly and safely.

“Throughout this Code, the voltage considered shall be that at which the circuit operates. The voltage rating of electrical equipment shall not be less than the nominal voltage of a circuit to which it is connected.”

110.5 Conductors. This is the bases of all electrical systems, where we need to bring electromagnetic(voltage and amperage) force with out interruption from one place to another inside the device and were it gets hooked up. In this we need to figure out what size the conductor should be. When we figure this out we look to the NFPA to do that. There is a table that looks at different insulation types of wire and gives us a rate of amperage that allows us to make a judgement of not just what size gauge but where the conductor shall be used in(what environment that wire will live). When cooper becomes to expensive we use aluminum. Aluminum isn’t resilient to amperage as cooper so it’s sized differently.

“Conductors normally used to carry current shall be of copper or aluminum unless otherwise provided in this Code. Where the conductor material is not specified, the sizes given in this Code shall apply to copper conductors. Where other materials are used, the size shall be changed accordingly.
Informational Note: For copper-clad aluminum conductors, see 310.15.”

110.6 Conductor Sizes. Sizing wire goes from 40 AWG (which is the smallest size wire) to 0000. This might not make sense to some but that is the way they made it work.

“Conductor sizes are expressed in American Wire Gage (AWG) or in circular mils.”

110.7 Wiring Integrity. Running a wire so that it is free from cuts in the insulation that will allow voltage to escape and not make the connection to where it needs to go so that it can be used to make a device work properly. This is called a short in the wire(conductor). When this happens and the device is grounded properly, the device used weather it be a fuse or a circuit breaker to interrupts the power.

“Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.”

110.8 Wiring Methods. From ridge pipe installation to romex these are example of acceptable methods of running conductors. The code sees these as ways to safely distribute power though out a dwelling weather it be a residential all the way through to industrial location.

“Only wiring methods recognized as suitable are included in this Code. The recognized methods of wiring shall be permitted to be installed in any type of building or occupancy, except as otherwise provided in this Code.”

110.9 Interrupting Rating. This is when we size the conductors to feed the devices we rate the breaker or fuse to that size not to damage the integrity of the wire. If we were to incorrectly size the conductor(wire) and that would be to small an amperage rating we see that the interruptions are frequent and causes nuisance tripping. When the opposite happens and the amperage rating is to high the insulation will melt away and cause a short tripping the breaker if properly wired(grounded).

“Equipment intended to interrupt current at fault levels shall have an interrupting rating at nomi‐ nal circuit voltage at least equal to the current that is available at the line terminals of the equipment.
Equipment intended to interrupt current at other than fault levels shall have an interrupting rating at nominal circuit voltage at least equal to the current that must be interrupted.”

110.10 Circuit Impedance, Short-Circuit Current Ratings, and Other Characteristics. When you look up impedance it means when measuring how much resistance there is measured in OHM’s. This will become important when talking about pools. Why, because when grounding a pool we want the path that the electrical current takes to be uninterrupted. When we allow this we can make assurance that the current will not want to go through anything other path other then the one we created for it to go though.

“The overcurrent protective devices, the total impedance, the equipment short-circuit current ratings, and other characteristics of the circuit to be protected shall be selected and coordinated to permit the circuit protective devices used to clear a fault to do so without extensive damage to the electrical equipment of the circuit. This fault shall be assumed to be either between two or more of the circuit conductors or between any circuit conductor and the equipment grounding conductor(s) permitted in 250.118. Listed equipment applied in accordance with their listing shall be considered to meet the requirements of this section.”

110.11 Deteriorating Agents. This is when have wire that gives us different insulation types. We want to be able to use devices that help us to measure, move, recognize, etc…… with out the danger of our equipment to fail. Because of our wiring failing because of the environment the wire lives in.

“Unless identified for use in the operating environment, no conductors or equipment shall be located in damp or wet locations; where exposed to gases, fumes, vapors, liquids, or other agents that have a deteriorating effect on the conductors or equipment; or where exposed to excessive temperatures.
Informational Note No. 1: See 300.6 for protection against corrosion.
Informational Note No. 2: Some cleaning and lubricating compounds can cause severe deterioration of many plastic mate‐ rials used for insulating and structural applications in equip‐ ment.
Equipment not identified for outdoor use and equipment identified only for indoor use, such as “dry locations,” “indoor use only,” “damp locations,” or enclosure Types 1, 2, 5, 12, 12K, and/or 13, shall be protected against damage from the weather during construction.
Informational Note No. 3: See Table 110.28 for appropriate enclosure-type designations. Informational Note No. 4: Minimum flood provisions are provi‐ ded in NFPA 5000-2015 Building Construction and Safety Code, the International Building Code (IBC), and the International Residential Code for One- and Two-Family Dwellings (IRC).”

110.12 Mechanical Execution of Work. When I read this I almost fell off my chair. This is because I have never herd a governing body look for a quality product when installing and yes this has to be important because it stops people from making a mess and not have the person do the installing from doing how ever. “Electrical equipment shall be installed in a neat and workmanlike manner.
Informational Note: Accepted industry practices are described in ANSI/NECA 1-2015, Standard for Good Workmanship in Electri‐ cal Construction, and other ANSI-approved installation standards.
(A) Unused Openings. Unused openings, other than those intended for the operation of equipment, those intended for mounting purposes, or those permitted as part of the design for listed equipment, shall be closed to afford protection substantially equivalent to the wall of the equipment. Where metallic plugs or plates are used with nonmetallic enclosures, they shall be recessed at least 6 mm (1∕4 in.) from the outer surface of the enclosure.
(B) Integrity of Electrical Equipment and Connections. Inter‐ nal parts of electrical equipment, including busbars, wiring terminals, insulators, and other surfaces, shall not be damaged or contaminated by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues. There shall be no damaged parts that may adversely affect safe operation or mechanical strength of the equipment such as parts that are broken; bent; cut; or deteriorated by corrosion, chemical action, or overheating.”

110.13 Mounting and Cooling of Equipment. Same as before the code is telling you to install is secure with some workman ship. You don’t want to pull off the wall.you want it to last.
“(A) Mounting. Electrical equipment shall be firmly secured to the surface on which it is mounted. Wooden plugs driven into holes in masonry, concrete, plaster, or similar materials shall not be used.
70 –44
NATIONAL ELECTRICAL CODE 2017 Edition
Informational Note No. 4: Minimum flood provisions are provided in NFPA 5000-2015 Building Construction and Safety Code, the International Building Code (IBC), and the International Residential Code for One- and Two-Family Dwellings (IRC).
(B) Cooling. This subject is becoming more and more important as time goes on with data centers popping up everywhere. Even personnel data centers need a certain amount of cooling. That said there is a demand for people with bitcoin mining machines at home. I know of people cooling those machines being cooled by mineral oil. I know right I would be a little worried about dipping my $5000.00 machine in liquid. It is the most efficient method of lowering the temperature of mining machines.
Electrical equipment that depends on the natu‐ ral circulation of air and convection principles for cooling of exposed surfaces shall be installed so that room airflow over such surfaces is not prevented by walls or by adjacent installed equipment. For equipment designed for floor mounting, clearance between top surfaces and adjacent surfaces shall be provided to dissipate rising warm air. Electrical equipment provided with ventilating openings shall be installed so that walls or other obstructions do not prevent the free circulation of air through the equipment.”

110.14 Electrical Connections. When installing a piece of equipment handling large loads it is important not only to install it with out damaged material but to get out the torque wrench. I have never seen an inspector with a torque wrench but I have been asked for one just to make sure that i did my due diligence in securing the screw type connectors to the proper torque setting.

“Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or alumi‐ num and copper-clad aluminum), unless the device is identi‐ fied for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.
Connectors and terminals for conductors more finely stran‐ ded than Class B and Class C stranding as shown in Chapter 9, Table 10, shall be identified for the specific conductor class or classes.

“(A) Terminals. Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. Connection by means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller conductors.
Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.
(B) Splices. Conductors shall be spliced or joined with splicing devices identified for the use or by brazing, welding, or soldering with a fusible metal or alloy. Soldered splices shall first be spliced or joined so as to be mechanically and electrically secure without solder and then be soldered. All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors or with an identified insulating device. Wire connectors or splicing means installed on conductors for direct burial shall be listed for such use.
(C) Temperature Limitations. The temperature rating associ‐ ated with the ampacity of a conductor shall be selected and coordinated so as not to exceed the lowest temperature rating of any connected termination, conductor, or device. Conductors with temperature ratings higher than specified for termi‐ nations shall be permitted to be used for ampacity adjustment, correction, or both.

(1) Equipment Provisions. The determination of termination provisions of equipment shall be based on 110.14(C)(1)(a) or (C)(1)(b). Unless the equipment is listed and marked other‐ wise, conductor ampacities used in determining equipment termination provisions shall be based on Table 310.15(B)(16) as appropriately modified by 310.15(B)(7).

(a) Termination provisions of equipment for circuits rated 100 amperes or less, or marked for 14 AWG through 1 AWG conductors, shall be used only for one of the following:
(1) Conductors rated 60°C (140°F).
(2) Conductors with higher temperature ratings, provided the ampacity of such conductors is determined based on the 60°C (140°F) ampacity of the conductor size used.

(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors. (4) For motors marked with design letters B, C, or D, conduc‐ tors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F)
ampacity.

(b) Termination provisions of equipment for circuits
rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following:
(1) Conductors rated 75°C (167°F)
(2) Conductors with higher temperature ratings, provided
the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors

(2) Separate Connector Provisions. Separately installed pres‐ sure connectors shall be used with conductors at the ampacities not exceeding the ampacity at the listed and identified temper‐ ature rating of the connector.
Informational Note: With respect to 110.14(C)(1) and (C)(2), equipment markings or listing information may additionally restrict the sizing and temperature ratings of connected conduc‐ tors. (D) Installation. Where a tightening torque is indicated as a numeric value on equipment or in installation instructions provided by the manufacturer, a calibrated torque tool shall be used to achieve the indicated torque value, unless the equip‐ ment manufacturer has provided installation instructions for an alternative method of achieving the required torque.

110.15 High-Leg Marking. When we see an orange outlet in the hospital we immediately assume that is backed up by generator power. Well when there is a delta transformer there is a leg with 208 to neutral. And the other legs are 120 phase to neutral and phase to phase we see 240 volts like we are used too. This is an incredible advantage for equipment that has provisions for this type of set up. More volts less amps. Less amps less heat and the wiring can be thinner. 14 AWG for instance.

“On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is orange in color or by other effective means. Such identification shall be placed at each point on the system where a connection is made if the grounded conductor is also present.”

110.16 Arc-Flash Hazard Warning. Arc flash is very dangerous, it damages , over time, the terminals of the devices that are experiencing the arc flashes condition. Arcing is destructive if not addressed properly
“(A) General. Electrical equipment, such as switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures, and motor control centers, that is in other than dwelling units, and is likely to require examination, adjustment, servicing, or maintenance while energized, shall be field or factory marked to warn qualified persons of potential electric arc flash hazards. The marking shall meet the requirements in 110.21(B) and shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment.

(B) Service Equipment. In other than dwelling units, in addition to the requirements in (A), a permanent label shall be field or factory applied to service equipment rated 1200 amps or more. The label shall meet the requirements of 110.21(B) and contain the following information:

(1) Nominal system voltage
(2) Available fault current at the service overcurrent protective devices
(3) The clearing time of service overcurrent protective devices based on the available fault current at the service equipment. (4) The date the label was applied. Exception: Service equipment labeling shall not be required if an arc flash label is applied in accordance with acceptable industry practice.
Informational Note No. 1: NFPA 70E -2015, Standard for Electrical Safety in the Workplace, provides guidance, such as determining severity of potential exposure, planning safe work practices, arc flash labeling, and selecting personal protective equipment. Informational Note No. 2: ANSI Z535.4-2011, Product Safety Signs and Labels, provides guidelines for the design of safety signs and labels for application to products.
Informational Note No. 3: Acceptable industry practices for equipment labeling are described in NFPA 70E -2015 Standard for Electrical Safety in the Workplace. This standard provides specific criteria for developing arc-flash labels for equipment that provides nominal system voltage, incident energy levels, arc-flash boundaries, minimum required levels of personal protective equipment, and so forth.”

110.18 Arcing Parts.

“Parts of electrical equipment that in ordinary operation produce arcs, sparks, flames, or molten metal shall be enclosed or separated and isolated from all combustible material.
Informational Note: For hazardous (classified) locations, see Articles 500 through 517. For motors, see 430.14.”

110.19 Light and Power from Railway Conductors. This is trying to say that the power(catenary) lines are used exclusively for powering the train, not the lighting or power of the train.

“Circuits for lighting and power shall not be connected to any system that contains trolley wires with a ground return.
Exception: Such circuit connections shall be permitted in car houses, power houses, or passenger and freight stations operated in connection with electric railways.”

110.21 Marking.

(A) Equipment Markings.

(1) General. This bring use the information we need to identify who makes the device, how much it uses in watts or amps, tells us the voltage needed to make the machine operate properly.

“The manufacturer’s name, trademark, or other descriptive marking by which the organization responsible for the product can be identified shall be placed on all electrical equipment. Other markings that indicate voltage, current, wattage, or other ratings shall be provided as specified else‐ where in this Code. The marking or label shall be of sufficient durability to withstand the environment involved.”

(2) Reconditioned Equipment. This will become important when discussing if the equipment works or not.

“Reconditioned equipment shall be marked with the name, trademark, or other descriptive marking by which the organization responsible for reconditioning the electrical equipment can be identified, along with the date of the reconditioning.
Reconditioned equipment shall be identified as “reconditioned” and approval of the reconditioned equipment shall not be based solely on the equipment’s original listing.
Exception: In industrial occupancies, where conditions of maintenance and supervision ensure that only qualified persons service the equipment, the markings indicated in 110.21(A)(2) shall not be required.
Informational Note: Industry standards are available for applica‐ tion of reconditioned and refurbished equipment. Normal serv‐ icing of equipment that remains within a facility should not be considered reconditioning or refurbishing.”

(B) Field-Applied Hazard Markings. So here they are telling us that when marking the equipment the owner of the

“Where caution, warning, or danger signs or labels are required by this Code, the labels shall meet the following requirements: (1) The marking of the hazards using effective words, colors, symbols, or any combination thereof.
Informational Note: ANSI Z535.4-2011, Product Safety Signs and Labels, provides guidelines for suitable font sizes, words, colors, symbols, and location requirements for labels.
(2) The label shall be permanently affixed to the equipment or wiring method and shall not be handwritten.
Exception to (2): Portions of labels or markings that are variable, or that could be subject to changes, shall be permitted to be handwritten and shall be legible.
(3) The label shall be of sufficient durability to withstand the environment involved.
Informational Note: ANSI Z535.4-2011, Product Safety Signs and Labels, provides guidelines for the design and durability of safety signs and labels for application to electrical equipment.”

110.22 Identification of Disconnecting Means.
“(A) General. Each disconnecting means shall be legibly marked to indicate its purpose unless located and arranged so the purpose is evident. The marking shall be of sufficient durability to withstand the environment involved.
(B) Engineered Series Combination Systems. Equipment enclosures for circuit breakers or fuses applied in compliance with series combination ratings selected under engineering supervision in accordance with 240.86(A) shall be legibly marked in the field as directed by the engineer to indicate the equipment has been applied with a series combination rating. The marking shall meet the requirements in 110.21(B) and shall be readily visible and state the following:
CAUTION — ENGINEERED SERIES COMBINATION SYSTEM RATED AMPERES. IDENTIFIED REPLACE‐ MENT COMPONENTS REQUIRED.
(C) Tested Series Combination Systems. Equipment enclosures for circuit breakers or fuses applied in compliance with the series combination ratings marked on the equipment by the manufacturer in accordance with 240.86(B) shall be legibly marked in the field to indicate the equipment has been applied with a series combination rating. The marking shall meet the requirements in 110.21(B) and shall be readily visible and state the following:
CAUTION — SERIES COMBINATION SYSTEM RATED ___ AMPERES. IDENTIFIED REPLACEMENT COMPONENTS REQUIRED. Informational Note: See IEEE 3004.5-2014 Recommended Practice for the Application of Low-Voltage Circuit Breakers in Industrial and Commercial Power Systems, for further information on series tested systems”

110.23 Current Transformers. When talking about potential energy we need to be careful. This goes for the code as well. The code does not want a person diagnosing a problem to get hurt by this. For that the equipped with short circuit wiring. Mostly used in power generating stations. The common person will not see these devices.

“Unused current transformers associated with potentially energized circuits shall be short- circuited.”

110.24 Available Fault Current. This is used to identify when a test for the equipment fault current was done so people performing a maintenance or testing can judge if it is safe to do so.
(A) Field Marking. Service equipment at other than dwelling units shall be legibly marked in the field with the maximum available fault current. The field marking(s) shall include the date the fault-current calculation was performed and be of sufficient durability to withstand the environment involved. The calculation shall be documented and made available to those authorized to design, install, inspect, maintain, or operate the system.
Informational Note: The available fault-current marking(s) addressed in 110.24 is related to required short-circuit current ratings of equipment. NFPA 70E -2015, Standard for Electrical Safety in the Workplace, provides assistance in determining the severity of potential exposure, planning safe work practices, and selecting personal protective equipment. (B) Modifications. When modifications to the electrical installation occur that affect the maximum available fault current at the service, the maximum available fault current shall be verified or recalculated as necessary to ensure the service equipment ratings are sufficient for the maximum available fault current at the line terminals of the equipment. The required field marking(s) in 110.24(A) shall be adjusted to reflect the new level of maximum available fault current.
Exception: The field marking requirements in 110.24(A) and 110.24(B) shall not be required in industrial installations where condi‐ tions of maintenance and supervision ensure that only qualified persons service the equipment.”

110.25 Lockable Disconnecting Means. LOTO(Lock Out and Tag Out) then working with potential energy this energy need to be shut off and locked out with the operator identifying him or her self, with date and a means of communication on the tag so for any questions.

“If a disconnecting means is required to be lockable open elsewhere in this Code, it shall be capable of being locked in the open position. The provisions for locking shall remain in place with or without the lock installed.
Exception: Locking provisions for a cord-and-plug connection shall not be required to remain in place without the lock installed.”