Table of Contents

• Introduction
  
• Circuit Overload Protection
  
• Use of Extension Cords
  
• Electrical Grounding
  
• Inspection and Testing of Equipment
  
• Appendix 1: Checklist

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Introduction

Electricity is an inherently dangerous but versatile source of energy. When it is utilized according to sound safety principles, personal injury and property damage can be effectively prevented. This section contains general information for the safe use of electricity. The National Electrical Code, as amended, OSHA 1910.301-308, and local electrical codes contain specific instructions for electrical circuitry and appliances. These references are available through the Department of Environmental Health and Safety.

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Circuit Overload Protection

Overloading electrical circuits is extremely dangerous and should not be permitted at any time. All systems shall be installed as intended by the manufacturer and in accordance with the National Electrical Code and local electrical codes.

Each electrical circuit breaker or fuse should be clearly marked with the name of the electrical appliance served by that circuit. Breaker or fuse identification allows for interruption of the electrical current to the circuit in the event of an emergency due to electrical shock or faulty appliances, and assists in identification of circuit overloading. Breaker boxes should be accessible at all times.

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Use of Extension Cords

Extension cords used with portable tools should be of the three-wire type with three prong plugs, except when using double insulated tools. Plugs should be nonconductive. The user should ensure that the wire sizes of extension cords are capable of handling the load without heating.

Multiple plug-on attachments on extension cords shall not be used.

Ensure that all extension cords are serviceable and free of exposed wiring and splices, frayed areas and/or deteriorated insulations.

Extension cords must only be used for temporary purposes, not for permanent installation. Where there is a permanent need for an electrical outlet, one should be installed.

While in use, the extension cord must not be placed in such a manner as to present a tripping hazard.

Extension cords must not be placed under rugs, carpets or chair mats. Extension cords must not be placed where they may be damaged by foot or vehicular traffic.

Extension cords must not be run through holes in walls or ceilings or through doorways or windows.

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Electrical Grounding

All electrically operated appliances shall be effectively grounded.

Electrically operated appliances may be grounded in the following ways:

• By an approved grounding type attachment plug, provided the ground wire is attached to the metal enclosure of the electrical conductors and to the plug connected to the equipment cord. The ground wire must be attached at all times while the equipment is connected to the power supply.
• By means of a grounding conductor run with the power conductors in the flexible cord connected to the appliance. The ground connection must always make contact with the electrical outlet ground while the appliance is connected to the power supply conductors.

Tools or appliances protected by an approved system of double insulation, or its equivalent, need not be grounded.

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Inspection and Testing of Equipment

All electrical equipment should bear the label of a nationally recognized testing laboratory such as the Underwriter's Laboratory (UL) or the Factory Mutual Engineering Corp. (FM).

Personnel should conduct periodic inspections of all equipment to ensure that all cords are free of wear and splices, and that the casing or insulating covering is free of cracks, holes, or other damage. Ensure also that all covers are in place and that circuit interlocks are functioning where applicable.

Any electrical equipment that is damaged, malfunctioning or shows signs of unusual, excessive heating or producing "burning" odors, should be pulled from service and submitted for repair by qualified personnel.

Electrical wall outlets should be free of cracks, breaks, or other obvious damage. Outlet damage must be reported immediately to Project Control for repair.

If equipment produces shock, no matter how small, it should be removed from service and immediately repaired by a qualified electrician before returning to service.

Personnel should avoid excess bending, stretching and kinking of electrical supply cords. Cords must never be jerked from wall outlets. Cords must never be stapled, tacked, or nailed to walls or floors because insulation can be damaged by these devices, exposing bare wires.

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Appendix 1: Checklist

The following Checklist is intended to assist the reader in determining the degree of compliance, within his/her operation, with the requirements of this procedure. Any "no" answer should be cause for concern and corrective action.

	Yes	No
Is electrical equipment free from recognized hazards which are likely to cause death or serious physical harm to employees?
Are any electrical circuits overloaded by the use of either an expansion device or extension cords?
Is each electrical circuit breaker or fuse clearly marked with the name(s) of the electrical appliance served by that breaker or fuse?
Are all extension cords used for portable equipment the three-wire type with three prong plugs?
Are the wire sizes of any extension cords capable of handling the load without heating?
Are all appliance cords and extension cords free of exposed wiring and splices?
Are any extension cords being used in lieu of a permanent installation?
Do any appliance or extension cords present a tripping hazard?
Are all appliances appropriately grounded?
Does all electrical equipment bear a UL or FM or other appropriate label?
Are all equipment cords free of signs of wear or splices?
Are all insulating covers free of cracks, holes or other signs of damage?
Is all electrical equipment sound, without visible damage, excessive heating, a "burning" smell?
Are all electrical wall outlets sound and free of cracks, breaks or other signs of damage?
Does any electrical equipment cause any degree of shock when touched?
Are any electrical cords bent, stretched or kinked?
Are only certified electricians allowed to repair electrical equipment?
Is all equipment which may arc, spark or flame kept separated and isolated from combustible material?
Is there sufficient clearance around electrical equipment for workers to move about freely?

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