General Information for Electrical Installations Chapter One General Information for Electrical Installations

Objectives After studying this chapter, you should be able to: Understand the basic safety rules for working on electrical systems Access the Internet to obtain a virtual unlimited source of safety and technical related information 2

Objectives (cont’d.) Become familiar with important electrical codes, safety codes such as NFPA 70, 70A, 70B, 70E, 73, OSHA, NIOSH, ADA, NRTL, and the ICC Learn about licensing, permits, plans, specifications, symbols, and notations Understand the role of the electrical inspector and the International Association of Electrical Inspectors 2

Objectives (cont’d.) Understand the metric system of measurement Understand the role of nationally recognized testing laboratories (NRTLs) and the necessity for listed equipment 2

Safety in the Workplace Safety First… Safety Last… Safety Always! There are dangerous voltages in residential electrical work Shocks can cause secondary hazards such as falling Fault currents can cause arc blasts 4

Safety in the Workplace (cont’d.) Lockout/Tagout (LOTO): physical restraint of all hazardous energy sources that supply power to a piece of equipment Safety measures are required by law Practice good housekeeping 5

FIGURE 1-3 A lock-off accessory that can be added to circuit breakers allows for adding a padlock and tag to in circuit breakers allows for adding a padlock and tag to individual circuit breakers in a panelboard. © Cengage Learning 2015

Safety in the Workplace (cont’d.) Only qualified persons may work on energized or “live” equipment The NEC® defines a qualified person as: “One who has skills and knowledge related to the construction and operation of the equipment and has specific safety training on the hazards involved” Reprinted with permission from NFPA 70-2014

Personal Protective Equipment Includes rubber gloves, insulating shoes and boots, face shields, safety glasses, hard hats, etc. OSHA states that: Employers should provide training on personal protective equipment (PPE) use Conductive jewelry should not be worn if contact with exposed energized parts is a possibility

Arc Flash On large electrical installations, an arc flash can generate temperatures of 35,000°F Don’t get complacent when working on electrical equipment Don’t be fooled by the size of the service Don’t assume that if you cause a fault on the load side of the main disconnect that the main breaker will trip off

Arc Flash (cont’d.) Classifying electrical injuries Time is important in life-threatening situations Four main types of electrical injuries: Electrical shock Electrocution Burns Falls

Arc Flash (cont’d.) Steps to take in the event of electrocution: Recognize that an emergency exists Call 911 for experienced assistance Don’t touch the person if he is in contact with a live circuit Shut off electrical power Perform CPR if person is not breathing Timing is everything!

Arc Flash (cont’d.) Using the proper tools is vital Digital multimeters High-quality digital multimeters reduce the risk of electrical shock Multimeters should be category rated based on location of the equipment to be tested Cat IV: high fault current Cat I: very low fault current

Training Take advantage of safety seminars Participate in formal training programs such as OSHA’s Training Institute Use the Internet to obtain safety information www.OSHA.gov www.cdc.gov/niosh www.nsc.org www.cpsc.gov www.nfpa.org

Safety Cannot Be Compromised! Don’t take chances! Use the right tools! Turn off the power Follow a lockout/tagout procedure Mark the tag with a description of exactly what that particular disconnect controls Visit safety websites for information

Licensing and Permits Electrical licensure of electricians and contractors is generally required Most communities require electrical permits Electrical permits document what work is to be done, who is doing the work, and inspection schedules 8

Licensing and Permits (cont’d.) Homeowners are usually allowed to pull permits and do electrical work on their own home where they live Construction requirements are provided in the construction plans, prints, or drawings 9

Plans and Specifications The plans convey details for construction and contain a materials list Specifications Normally accompany each set of plans Written instructions and information about job Prevent confusion of details. Take preference over the plans if a difference between the two exists 11

Symbols and Notations Symbols and notations are used to simplify drawings Symbols are standard graphics as adopted by the American National Standards Institute (ANSI)

Symbols and Notations (cont’d.) Symbols present information about devices, appliances, and equipment Notations are on the drawing in the form of text and generally next to the symbol that needs additional explanation

The National Electrical Code® (NEC®) The NEC® provides a standard for electrical work that is widely adopted by local governments The NEC® is sponsored by the National Fire Protection Association (NFPA) 15

NEC® (cont’d.) The NEC® is constantly being revised A new code is published every three years Obtain latest edition of the NEC NFPA 70 National Fire Protection Association www.nfpa.org The International Association of Electrical Inspectors (IAEI) www.iaei.org 16

NEC® (cont’d.) Definitions of electrical terms are often found in Article 100 of the NEC® The 2011 edition is the most recent, but many locales still use older editions Electrical installations have to comply with other community-adopted building codes and standards 17

NEC® (cont’d.) Electrical Inspection Code for Existing Dwellings Published by NFPA; referred to as NFPA 73 Evaluates safety, fire, and shock hazards of the electrical installation For electricians doing remodel work For inspectors in bringing an existing dwelling to a safe condition 28

Building Codes Other code organizations ICC, ANSI, IAEI Know code definitions (NEC® 90, 100) Read 110.3(B) carefully! “Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.” Reprinted with permission from NFPA 70-2014 29

Metrics (SI) and the NEC® Metric and standard systems are both supported by the NEC® Calculations using metrics or standard result in slightly different values Calculations in either metrics or inch-pounds are in compliance with the NEC®, 90.9(D)

Listed Equipment and Nationally Recognized Testing Laboratories OSHA rules state that: All electrical products installed in the work place shall be listed, labeled, or otherwise determined to be safe by a nationally Recognized Testing Laboratory (NRTL).

Listed Equipment and NRTL (cont'd.) The American National Standards Institute (ANSI) works with Underwriters Laboratories (UL) and other organizations to set basic standards for electrical equipment NRTL is the “third party,” testing products in an effort to reduce safety risks

Listed Equipment and NRTL (cont'd.) After the NRTL tests the product and it complies with the safety standard, the product is then listed and will have listing markings, or labels

Listed Equipment and NRTL (cont'd.) Products are tested for safety Tested products that meet the safety standard are listed and labeled A listed product must be used and installed properly to assure safety 22

Listed Equipment and NRTL (cont'd.) Some recognized testing laboratories Underwriters Laboratories, Inc. (UL®) CSA International, formerly known as the Canadian Standards Association Intertek Testing Services NA, Inc. (ITS) National Electrical Manufacturers Association (NEMA) 24