Don't be Shocked...
Out of 4,379 worker fatalities in private industry from 2015 onward, there were 937 (21.4%) in construction — that is, one in five worker deaths happened within our peer group. The leading causes of private sector worker deaths (excluding highway collisions) in the construction industry were falls, followed by struck by object, electrocution, and caught-in/between.
These "Fatal Four" were responsible for more than half (64.2%) the construction worker deaths in 2015, BLS reports. Eliminating the Fatal Four would save 602 workers' lives in America every year. This bulletin will focus on the third leading cause of workplace fatalities, electrocutions. There were 81 electrocutions in the construction field, that was 8.6% of the total fatalities for 2015.
The greatest potential for electrocutions comes from the tools we use. Therefore, the best efforts to accomplish our goal of “Safe Production” is to provide engineering controls to each potential electrical hazard. At Wachs while in the field we verify and document a working grounding grid or use a Ground Fault Circuit Interrupter (GFCI) and in our shops at Belmont and Jackson we have permanent, tested to code grounding systems. The intention of this is to provide an over-current protection that instantaneously de-energizes an electrical circuit to protect personnel from electric shock. A large percentage of electrical accidents are caused from using improperly grounded temporary electrical systems or damaged power tools and extension cords on the jobsite. When utilized correctly Wachs procedure of confirmed verification of grounding systems or use of a GFCI will greatly reduce the chance of shock from a ground fault. For our field work where an established grid doesn't exist, the National Electrical Code for grounding conductors requires that a system grounding conductor be connected to any local metallic water-piping system available on the premises, provided the length of the buried water piping is a minimum of 10 feet. On a temporary jobsite, most times this isn’t available, when this happens a grounding electrode must be utilized. Again, not always possible. With the improbability of the previous mentioned installed grounding types it makes sense to use Ground Fault Circuit Interrupters (GFCI). Not only will their use will save time it could also save being shocked.
GFCI’s are available in a short extension cord configuration and are a simple means to achieve protection from electrical shock hazards. However, keep in mind that GFCI’s are not foolproof, and under wet conditions are not always effective. Fatal shocks are most likely to occur under damp or wet conditions or if the user of an electrical device is touching a metal object such as a ladder or pipe.
Electrical Extension Cords
Electrical Extension Cords are common to all jobs sites. If not carefully chosen for the job and properly cared for, these can be an incident waiting to happen. Again, Wachs Assured Ground Procedure states that a quarterly inspection must be conducted, then documented with each cord (and corded tool). If the wrong length or size of cord is selected for a tool then the voltage available is reduced to the tool, creating an over-current hazard. Plugs and receptacles must match the job at hand. Each type of receptacle is designed to handle a specific amount of voltage and current. Always be aware of your circuit requirements.
Most plug-in electrical tools manufactured today are designed to reduce the danger of electrical shock and have plastic housings, double insulation, and other safety features. If possible, use only tools of this type.
Specific OSHA regulations that cover grounding requirements on the jobsite:
A conductor used as a grounded conductor or as an equipment ground shall be identifiable and distinguishable from all other conductors.
No grounded conductor shall be attached to any terminal or lead so as to reverse designated polarity.
A grounding terminal or grounding-type device on a receptacle, cord connector, or attachment plug shall not be used for any other purpose.
The employer shall use either a GFCI or assured equipment grounding conductor program as specified to protect employees on construction jobsites. These requirements are in addition to any other requirements for equipment grounding conductors.
All 120-volt, single-phase, 15- and 20-ampre receptacle outlets on construction sites, which are not a part of the permanent wiring of the build-ing or structure and which are in use by employees, shall have approved GFCI’s for personnel protection.
Receptacles on a two-wire, single-phase portable or vehicle-mounted generator rated not more than 5KW where the circuit conductors of the generator are insulated from the generator frame or other grounded surfaces need not be GFCI protected.
The frame of a portable generator need not be grounded if the generator supplies only equipment mounted on the generator and/or cord- and plug-connected equipment through receptacles mounted on the generator, and the noncurrent-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame.
Vehicle mounted generators may use the vehicle frame as the grounding electrode if the frame of the generator is bonded to the vehicle frame and the generator supplies only equipment located on the vehicle and/or cord-and plug-connected equipment through receptacles mounted on the vehicle or on the generator if receptacles are bonded to the generator frame.
Wachs has established procedures that ensure we are not only compliant with OSHA laws and our clients’ requirements but also provide a safe and productive working environment. When dealing with GFCI and/or extension cords we suggest that you review Section 17 in the Wachs Safety Manual, Assured Grounding Procedure.