Important NFPA Articles for Electrical Test Technicians

NFPA 70 and 70E are two of the most referenced standards among electrical workers. The electrical code and associated safe work practices apply to nearly any field in the electrical industry.

Electrical test technicians are required to have extensive knowledge of the electrical code in order to properly perform visual and mechanical inspections. The following articles have been found to have extra relevance in the field and a high importance on certification exams.

NFPA 70 – National Electrical Code (NEC)

The National Electrical Code (NEC) is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. First published in 1897, the NEC is updated once every three years.

NFPA 70 is not federal law. Instead, NEC standards are either adopted by local governments or local governments create and enforce their own electric code based on NFPA or other nationally recognized standards.

Article 90 – Introduction

  • Sets boundaries and explains how the Code is arranged.
  • Describes the scope of the Code—what it covers and what it does not cover.

Article 110.16 - Arc-Flash Hazard Warning. Service Equipment

  • Provides specific rules for equipment with arc flash labels.
  • Marking requirements apply when a 1200 amp or larger electric service is installed at other than dwelling units.
  • Required for equipment likely to require examination, adjustment, servicing, or maintenance while energized.

Article 110.21 - Field-Applied Hazard Markings

  • Requires manufacturer’s name, trademark or other descriptive marking.
  • Specifies field applied hazard markings must adequately warn of the hazard using effective words and/or colors and/or symbols in 110.21(B).
  • Specifies marking requirements for Reconditioned equipment in 110.21(A)(2).

Article 225.56 - Inspections and Tests for Outside Branch Circuits and Feeders

  • Provides pre-energization and operating test requirements for outside branch circuits and feeders over 1000 volts that run on (or between) structures or poles.
  • Requires the complete electrical system design be performance tested when first installed on-site.
  • Specifies requirements for Instrument Transformers, Protective Relays, Switching Circuits, Control and Signal Circuits, Metering Circuits, Acceptance Tests, Relays, Metering, and Test Reports.
  • Defines identification requirements for services, feeders, and branch circuits.
  • AHJ must be satisfied that the performance tests demonstrate proper operation prior to energization.

230.95 - Ground Fault Protection of Equipment

  • Specifies that ground fault protection of equipment be provided for solidly grounded wye electric services of more than 150 volts to ground but not exceeding 1000 volts phase-to-phase for each service
    disconnect rated 1000 amperes or more.
  • Does not apply to systems where the grounded conductor is not solidly grounded, such as high-impedance grounded neutral.
  • Specifies the maximum setting of the ground-fault protection be 1200 amperes.
  • Specifies the maximum time delay be one second for ground-fault currents equal to or greater than 3000 amperes.
  • Requires ground-fault protection system be performance tested by a qualified persons using primary injection when first installed on site.

Related: Ground Fault Protection Systems: Performance Testing Basics

Article 250 - Grounding and Bonding

  • Largest and most complex article organized into 10 different parts.
  • Sets specific requirements with regards to bonding and grounding.
  • Identifies the installation methods that must be followed to insure a safe electrical installation.
  • Requires that the electrical system is guarded against electric shock and fires by limiting the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and as well as a ground-fault (line-to-case fault).
  • Defines the requirements for Concrete-Encased Electrodes.

Related: 4 Important Methods of Ground Resistance Testing

Article 310 - Conductors for General Wiring

  • Completely reorganized in 2020 edition, medium voltage requirements moved to article 311.
  • Only applies to conductors rated up to and including 2000 volts.
  • Defines conductor marking requirements, conductor applications, and insulation properties.
  • Provides the requirements for conductors in parallel.

Related: Low Voltage Cable Testing and Inspection Techniques

Article 311 - Medium Voltage Conductors and Cable

  • Covers the use, installation, construction specifications, and ampacities for Type MV medium voltage conductors and cable.
  • Contains medium voltage requirements located in separate articles prior to 2020 edition.
  • Ampacity tables for medium voltage cables were previously located in Article 310.
  • Installation requirements were previously located in Article 328.

Related: Power Cable Testing and Diagnostics Overview

Article 700 - Emergency Systems

  • Specifies the authority having jurisdiction (AHJ) determines whether or not an emergency system is necessary for a given facility.
  • Requires that the AHJ conduct (or witness) an acceptance test of the emergency system upon completion — and periodically afterward.
  • States a temporary alternate source of power must be available whenever the emergency generator is out of service for more than a few hours.
  • Specifies marking requirements to indicate the type and location of on-site emergency power sources.
  • States that upon loss of normal power, emergency power must be available within 10 seconds.
  • Requires that storage batteries must be of suitable rating and capacity to supply and maintain the total load for 90 minutes. Voltage applied to the load can’t fall below 87.5% of normal.
  • Permits the use of alternate emergency services if served by a separate service drop or lateral, and are electrically and physically separated from all other service conductors.
  • Specifies that on-site fuel supply must provide not less than 2 hours of full-demand operation of the system.

Related: Transfer Switch Testing and Maintenance Guide

NFPA 70E – Standard for Safe Electrical Work Practices

NFPA 70E covers electrical safety requirements for employees, including the proper selection, use, and care of personal protective equipment (PPE). The document describes safe work practices for electrical construction and maintenance but does not specify how to safely design or install electrical systems.

Article 100 - Definitions

Contains definitions of technical terms considered fundamental to the proper understanding of key requirements. When discussing a requirement, the parties involved must know the intended meaning of each term. Many of the definitions found in NFPA 70E are taken directly from NFPA 70.

Article 110 - General Requirements

Covers the overall requirements for formulating and implementing an electrical safety program, including policies, risk assessment, and employee training. It also specifies requirements for program and field auditing, documenting, and the relationships between the types of employers.

Article 120 - Establishing an Electrically Safe Work Condition (ESWC)

Requires employers to establish, document, and implement a lockout/tagout program and specify lockout/tagout procedures to safeguard workers from exposure to electrical hazards. All of the requirements in Article 120 must be applied before an ESWC is achieved.

Related: NFPA 70E Arc Flash and Shock Hazard Boundaries Explained

Article 130 Work Involving Electrical Hazards

Covers requirements for work involving electrical hazards when an electrically safe work condition cannot be established. It also describes the situations under which energized electrical work can be justified and the necessary requirements for working safely with energized electrical equipment.

Related: Electrical Shock and Arc Flash PPE Overview