ELECTRICAL SAFETY

Electrically powered equipment can pose a significant hazard to workers, particularly when mishandled or not maintained.  Many electrical devices have high voltage or high power requirements, carrying even more risk.

Electrical Safety Protective Methods

Use of Protective Equipment

Employees working in areas where there are potential electrical hazards must be provided with and use electrical protective equipment appropriate for the parts of the body to be protected and the work performed. Protective equipment must be maintained in a safe, reliable condition and be periodically inspected or tested as required by 29 CFR 1910.137, Electrical Protective Devices. Where the insulating capability of protective equipment is subject to damage during use, the insulating material must be protected by covering with leather or other appropriate materials. Nonconductive head protection must be worn wherever there is danger of head injury from electrical shock or burns due to contact with exposed energized parts. Protective equipment for the eyes must be worn where there is danger of eye and/or face injury from electric arcs and flashes or flying objects resulting from electrical.

General Protective Equipment and Tools

Insulated tools and handling equipment must be used by employees working near exposed energized conductors or circuit parts if the tools and/or equipment may make contact with the conductors or parts.  The insulating material of tools and equipment must be protected where it is subject to damage. Fuse handling equipment, insulated for the circuit voltage, must be used to remove or install fuses when the fuse terminals are energized.  All ropes and hand lines used near exposed energized parts must be nonconductive. Protective shields, protective barriers, or insulating material must be used to protect employees from shock, burns, or other electrical related injuries while employees are working near exposed energized parts which might be contacted or where dangerous electric heating or arcing might occur.  When normal enclosed live parts are exposed for maintenance or repair, the parts must be guarded to protect unqualified persons from contact with the live parts.

Alerting Techniques

Alerting techniques must be used to warn and protect employees from electrical shock hazards, burns, or failure of electric equipment parts. Safety signs, safety symbols, or accident prevention tags must be used where necessary to warn employees about electrical hazards which may endanger them. Barricades should be used in conjunction with safety signs where necessary to prevent or limit employee access to work areas exposing employees to un-insulated energized conductors or circuit parts.  Conductive barricades must not be used where they might cause an electrical contact hazard. An attendant should be stationed to warn and protect employees where signs and barricades do not provide sufficient warning and protection.

Arc Flash Personal Protective Equipment

This Personal Protective Equipment provides protection after an arc flash incident has occurred and should be viewed as the last line of protection. Selection of the appropriate PPE for the task to be performed is based upon hazard categories found in NFPA 70E – 2004, which should appear on labeled electrical panels and equipment.

Working Outdoors and Extension Cords

Working Outdoors

Electrical hazards on construction or renovation sites or work performed outdoors must be controlled through the use of Ground Fault Circuit Interrupters (GFCIs).

  • All 120-volt, single-phase, 15 or 20 ampere receptacles that are not part of permanent wiring must be protected by GFCIs.  (Receptacles on smaller generators are exempt under certain situations.  Consult with your supervisor or EHS with any questions.).
  • Light bulbs used for general illumination must be protected from breakage.
  • Temporary lights must not be suspended by their cords, unless so designed.
  • Portable lights or tools used in wet or conductive locations must be protected by GFCIs or operate at 12 volts or less.

Extension Cords

  • Workers must visually inspect extension cords and cord and plug connected equipment daily before use.   Damaged extension cords must be removed from service and destroyed.  Damaged or defective equipment must be removed from service and destroyed or repaired by a qualified electrician.
  • Extension cords must be three-wire type.  Extension cords or flexible cords used for lighting must be designed for hard or extra hard usage (e.g., types S, ST, SO)
  • Flexible cords must be connected to devices and fittings so that strain relief is provided and prevents pull from being directly transmitted to joints or terminal screws.

 

Source: https://ehs.princeton.edu/book/export/html/75

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