Employer Responsibilities to Protect Workers from Electrocutions

Ensure Overhead Power Line Safety

Overhead power lines must be deenergized and grounded by the owner or operator of the lines, or other protective measures must be provided before work is started, such as PPE (rubber insulating gloves, hoods, sleeves, matting, blankets, line hose, and industrial protective helmets). Protective measures (such as guarding or insulating the lines) must be designed to prevent contact with the lines.

There are three major ways employers should control power line hazards:

• Maintaining a safe distance from lines;
• Having the power company de-energize and ground the power line(s). Have a power company representative at the site; and
• Having the power company install insulated sleeves (also known as "eels") over power lines.

Employers should train workers regarding power line hazards and about the available protective measures. Workers need to be fully informed about what jobs may have electrical hazards, and the measure(s) they will take to control the hazards. Also, workers should be reminded that they should always ask questions if they have any doubts about maintaining safe working conditions.

Isolate Electrical Parts

Electrical parts, conductors entering boxes, cabinets, or fittings shall be protected from abrasion, and openings through which conductors enter and shall be effectively closed. Unused openings in cabinets, boxes, and fittings shall also be effectively closed.

All pull boxes, junction boxes, and fittings shall be provided with covers. Metal covers shall be grounded. In energized installations each outlet box shall have a cover, faceplate, or fixture canopy. Covers of outlet boxes having holes through which flexible cord pendants pass shall be provided with bushings designed for the purpose or shall have smooth, well-rounded surfaces on which the cords may bear.

Supply GFCI

OSHA ground-fault protection rules and regulations have been determined necessary and appropriate for worker safety and health. Therefore, it is the employer's responsibility to provide one of the following:

• Ground-fault circuit interrupters on construction sites for receptacle outlets in use and not part of the permanent wiring of the building or structure
• A scheduled and recorded assured equipment grounding conductor program on construction sites, covering all cord sets, receptacles which are not part of the permanent wiring of the building or structure, and equipment connected by cord and plug which are available for use or used by workers

Receptacles on the ends of extension cords must be protected by GFCI. GFCI circuit breakers are installed in the main circuit board. They protect an entire circuit.

The employer is required to provide approved ground-fault circuit interrupters for all 120-volt, single-phase, 15- and 20-ampere receptacle outlets on construction sites which are not a part of the permanent wiring of the building or structure and which are in use by workers.

GFCI monitor the current-to-the-load for leakage to ground. When this leakage exceeds 5 mA ± 1 mA, the GFCI interrupts the current. They are rated to trip quickly enough to prevent electrocution.

Establish and Implement an Assured Equipment Grounding Conductor Program (AEGCP)

The assured equipment grounding conductor program (AEGCP) covers all cord sets, receptacles which are not a part of the permanent wiring of the building or structure, and equipment connected by cord and plug that are available for use or used by employees. OSHA requires that a written description of the employer's assured equipment grounding conductor program, including the specific procedures adopted, be kept at the jobsite. This program should outline the employer's specific procedures for the required equipment inspections, tests, and test schedule.

The required tests must be recorded, and the record must be maintained until replaced by a more current record. The written program description and the recorded tests must be made available at the jobsite to OSHA and to any affected employee upon request. The employer is required to designate one or more competent persons to implement the program.

Electrical equipment noted in the assured equipment grounding conductor program must be visually inspected for damage or defects before each day's use. Any damaged or defective equipment must not be used by the employee until repaired.

A continuity test is required by OSHA to ensure that the equipment grounding conductor is electrically continuous. It must be performed on all cord sets, receptacles that are not part of the permanent wiring of the building or structure, and on cord- and plug-connected equipment that is required to be grounded. This test may be performed using a simple continuity tester, such as a lamp and battery, a bell and battery, an ohmmeter, or a receptacle tester.

Ensure Power Tools Are Maintained in Safe Condition

The employer needs to ensure that all power tools and equipment are maintained in a safe condition by doing the following:

• Ground power supply systems, electrical circuits, and electrical equipment.
• Frequently inspect electrical systems to ensure path to ground is continuous.
• Ensure workers understand they must inspect electrical equipment prior to use.
• Ensure ground prongs are not removed from tools or extension cords.
• Ground exposed metal parts of equipment.

Ensure Proper Guarding

Guarding involves locating or enclosing electrical equipment to ensure workers do not accidentally come into contact with its live parts.

Effective guarding requires equipment with exposed parts operating at 50 volts or more to be placed where they are accessible only to authorized people qualified to work with/on the equipment. Recommended locations include the following:

• A room, vault, or similar enclosure
• A balcony, gallery, or elevated platform
• A site elevated eight feet or more above the floor

Sturdy, permanent screens can also serve as effective guards.

Provide Training

Workers need be trained in and familiar with the safety-related work practices that pertain to their respective job assignments. Train workers working with electric equipment in safe work practices, including the following:

• Deenergize electric equipment before inspecting or repairing.
• Use cords, cables, and electric tools that are in good repair.
• Use lockout/tagout recognition and procedures.
• Use appropriate protective equipment.

Enforce LOTO Safety-Related Work Practices

Controls that are to be deactivated during the course of work on energized or de-energized equipment or circuits shall be locked out, tagged, or both.

Equipment or circuits that are deenergized shall be rendered inoperative and have post tags attached at all points where such equipment or circuits can be energized.

Tags shall be placed to plainly identify the equipment or circuits being worked on.

While any worker is exposed to contact with parts of fixed electric equipment or circuits that have been de-energized, the circuits energizing the parts shall be locked out, tagged out, or both.

Ensure Proper Use of Flexible Cords

The OSHA construction standard requires flexible cords to be rated for hard or extra-hard usage. These ratings are derived from the National Electrical Code and are required to be indelibly marked approximately every foot along the length of the cord.

Examples of these codes are S, ST, SO, and STO for hard service and SJ, SJO, SJT, and SJTO for junior hard service.

Extension cords must be 3-wire type so they may be grounded, and to permit grounding of any tools or equipment connected to them.

Limit exposure of connectors and tools to excessive moisture by using watertight or sealable connectors.

To learn more about Focus Four Safety visit our Construction Focus Four Safety Online Training web page.