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Course 715 - Electrical Safety for Technicians & Supervisors

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Safety guides and audits to make your job as a safety professional easier

Working on Live Circuits

Introduction

Working on live circuits means actually touching energized parts. Working near live circuits means working close enough to energized parts to put you at risk even though you may be working on de-energized parts.

Common tasks where you need to work on or near live circuits include:

  • taking voltage and current measurements;
  • opening and closing disconnects and circuit breakers;
  • racking circuit breakers on and off the bus;
  • removing panels and dead fronts; and
  • opening electric equipment doors for inspection.

There should be standard written procedures and training for these common tasks. For instance, when opening and closing disconnects, use the left-hand rule when possible (stand to the right side of equipment with a disconnect on the right, and operate the disconnect with your left hand). For other situations where you might need to work on or near live circuits, your employer should institute a written live-work permit system, which must be authorized by a qualified supervisor.

Live-Work Permit System

A live-work permit should, at least, contain this information:

  • a description of the circuit and equipment to be worked on and the location,
  • explanation why the work must be done "live"
  • date and time covered by the permit
  • a description of the safe work practices to be used
  • results of shock hazard analysis and determination of shock protection boundaries
  • results of flash hazard analysis and determination of the flash protection boundary
  • PPE needed to safely perform the job
  • who will do the work and how will unqualified persons be kept away
  • evidence of completion of job briefing, including discussion of job-specific hazards
  • energized-work approval signatures (authorizing or approving management, safety officer, owner, etc.)

Safe Work Practices

To work on or near live parts, you must do the following:

  • Have a written live-work permit for the work to be done.
  • Wear the right PPE to protect against electric shock and arc flash. Never wear clothing made from synthetic materials, such as acetate, nylon, polyester, polypropylene, or rayon - alone or combined with cotton. Such clothing is dangerous because it can burn and melt into your skin.

    The PPE that is needed depends on the type of electric work being done. The minimum PPE required while working on line circuits would be an untreated natural fiber long-sleeve shirt and long pants plus safety glasses with side shields. Depending on the voltage and the electric task to be done, different types of PPE are required. Fire-resistant protective clothing can include multi-layer flash suit jacket and pants, wraparound face shield, double-layer switching hood, voltage-rated gloves with leather protectors, electrically rated hard hats, and so forth. [(See Table 130.7(C)(15)(A)(b) Arc-Flash Hazard PPE Categories for A/C systems, Table 130.7(C)(15)(B) Arc-Flash Hazard PPE Categories for D/C Systems, and Table 130.7(C)(16) Personal Protective Equipment (PPE)) NFPA 70E, 2015 Edition].

  • Use the proper type of protective equipment, such as insulated tools and/or handling equipment that is rated for the voltage. These can include insulated fuse or fuse holding equipment, nonconductive ropes and handlines, fiberglass-reinforced plastic rods, nonconductive portable ladders (such as, fiberglass), protective shields, rubber insulating equipment, voltage-rated plastic guards, and so forth.

Instructions

Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. Working on live circuits means working close enough to energized parts to put you at risk.

2. When using the "left-hand rule," the worker will stand _____ the disconnect.

3. Where you might need to work on or near live circuits, your employer should institute a written _____ system, which must be authorized by a qualified supervisor.

4. A live-work permit does not contain this information.

5. The _____ PPE required while working on live circuits would be an untreated natural fiber long-sleeve shirt and long pants plus safety glasses with side shields.


Have a great day!

Important! You will receive an "error" message unless all questions are answered.