NEC Updates: Six Code Changes for the Mining Industry

Stay Informed

Every three years, the National Electric Code (NEC) is updated, and as a result industry standards for the installation of electrical wiring and equipment are revised. The full NEC text spans approximately 1,000 pages, broken down into several chapters and annexes, and includes safety information that’s relevant to all industrial audiences.

While it is not an enforceable governing document, many industries recognize the NEC as the standard for electrical safety and choose to follow its recommendations and best practices. The mining industry is a prime example of this adoption.

Historic Challenges with Mining Governance

Two branches of the U.S. Department of Labor – the Occupational Safety and Health Administration (OSHA), and more specifically the Mine Safety and Health Administration (MSHA) – publish and maintain regulatory information to help maintain safe, healthy conditions for mining operations. While MSHA last updated their standards and regulations in 2006 when the Mine Improvement and New Emergency Response Act (MINER Act) was passed, it’s important to note the following:

  • Creating new regulatory legislation for mining is a lengthy, complex process requiring an Act of Congress
  • Prior to 2006, MSHA safety standards had not been updated since 1977 when the Federal Mine Safety and Health Act passed
  • Regulations in the MINER Act focused on accident preparedness and did not address many other key areas, including electrical safety

Considering the disparity between slow-moving mining regulation and rapidly changing technology, it’s clear to see why mining operations turn to the NEC for guidance on how they might safely bridge the gap to meet global demand for commodity.

2017 NEC Revisions: What's New? 

To help frame the full 2017 NEC update, here are the six code revisions that are the most relevant to the mining industry.

Article 110.3 Examination, Identification, Installation, Use and Listing of Equipment
Changes to this article state that examined equipment may be new, reconditioned, refurbished or remanufactured. In addition, new language was added stating that product testing, evaluation and listing (certification) must be conducted by recognized and qualified electrical testing laboratories.

Article 110.9 — Interrupting Overcurrent Protection Rating
Enforceable language was added to this article, stating that equipment designed to interrupt current at fault levels must have an interrupting rating at nominal circuit voltage at least equal to the current that is available. Also, equipment intended to interrupt current at other than fault levels must have an interrupting rating at nominal circuit voltage at least equal to the current that must be interrupted.

Article 110.14 — Conductor Termination and Splicing
A new section, D, regarding installations was added to this article, specific to torquing terminal connections. The language mentions using a properly calibrated tool to reach any notated numeric values either on the equipment itself or documented in the installation instructions. There is an exception to this code for instances where the manufacturer provides instructions for achieving the required torque value other than use of a calibrated tool.

Article 110.16 — Arc-Flash Hazard Warning
Requirements in Section B regarding service equipment labeling have been increased. The language now states that non-residential electrical equipment rated 1200 amps or more must include a permanent label with the following information:

  1. Nominal system voltage
  2. Available fault current at the service overcurrent protective devices
  3. Clearing time of service overcurrent protective devices based on available fault current at time of service
  4. The date the label was applied 
The above service equipment labeling requirements do not apply in instances where an industry-approved arc flash label is in place.

Article 210.8 — Ground-Fault Circuit-Interrupter (GFCI) Protection for Personnel
Section A for dwelling units states that GFCI protection is now required for 125-volt, single-phase, 15- and 20-ampere receptacles installed in unfinished portions or areas of the basement not intended to be inhabitable. In addition, GFCI protection must be in place where receptacles are installed within six feet of the top, inside edge of the bowl of a sink.
Section B for non-dwelling units mentions the same requirement for receptacles near sinks, but the ratings for the receptacle are increased to 150 volts, 50 amperes or less (single-phase) and 100 amperes or less (three-phase). GFCI protection is also now required for receptacles installed in crawl spaces and unfinished portions of basements.  

Article 210.12 — Arc-Fault Circuit-Interrupter Protection
Section B pertaining to dormitories has been expanded and now requires 120-volt, single-phase, 15- and 20-ampere branch circuits that supply devices be protected by any of the same means listed in section A of the same article, for dwelling units (items 1-6 can be viewed in the 2017 NEC). That same condition also applies to a new section, C, which focuses on guest rooms and guest suites.
Section D, regarding branch circuit extensions or modifications for dwelling units, has been expanded to include dormitories. The code states that in any area specified in article 210.12 A or B, where branch-circuit wiring is modified, replaced, or extended, the branch circuit shall be protected by:

  1. A listed combination-type AFCI located at the origin of the branch circuit, or
  2. A listed outlet branch-circuit-type AFCI located at the first receptacle outlet of the existing branch circuit.

An exception states that AFCI protection isn’t required if existing conductors are less than six feet long and don’t include additional outlets or devices.

Seeing 2020: Planning for the Next NEC Cycle

Many industry experts have weighed-in online offering their analysis of the NEC changes for 2017. While it’s not required by law for mining operations to comply with the NEC, it’s worthwhile to do some additional research to make sure your operation is up to code, prioritizing both the safety of your employees and optimizing the efficiency of your operation.

The NEC is scheduled to be revised again in 2020, bringing potential changes that even the best experts might not predict. Making time to dig into the details of this code and conducting an audit of your operation now could save you from a landslide of expensive, time-consuming upgrades in the future.