While working on an electrical line, promoting electrical safety is absolutely critical. The line you are working on could become energized in an instant, creating a dangerous, even deadly, situation. Lightning, human error, static electricity, induced voltage and backfeed are all serious dangers to line workers.
A top priority in electrical safety is keeping electricity grounded while work is performed. Grounding electricity prevents it from seeking your body as the grounding path. OSHA and ASTM have mandated specific requirements to ensure that you remain safely grounded by using the right equipment and keeping that equipment functioning properly through inspections, cleaning and recertification. Follow these requirements, as well as company best practices, to support a safe work zone where the probability of an incident is reduced.
Here are six steps to stay safe and grounded before and during electrical work.
1. Review Electrical Safety Practices Before Beginning
Completing a job safely always starts with knowing and understanding your company’s safe work practices. Creating a safe environment includes conducting a hazard assessment prior to work (see OSHA 29 CFR 1910.269(a)(3) and .269(c)). An assessment will guide you through the completion of a job in a safe and efficient manner from beginning to end. Proper grounding practices are also included in an assessment.
2. Get up to Electrical Grounding Standards
Protective grounding should have an electrical impedance low enough to cause the immediate operation of protective devices in case of accidental operation of the lines or equipment (OSHA 29CFR 1910.269(n)(4)). Grounding equipment must be capable of conducting the resulting fault current that could flow at the point of grounding for the time necessary to clear the fault. Use a professional testing facility when custom building ground sets to ensure that your equipment is up to code.
Installation and removal of protective grounding should always be done with live-line tools. The ground-end connection should be installed first and removed last when removing the grounds (OSHA 29CFR 1910.269(n)(6)). Liveline tools must be properly inspected before use for any damage that could inhibit their protective properties. Equipment that has suspected damage should be removed from use in the field (ASTM 711-02, 8.1) and sent to a professional testing facility.
According to John “Grizzy” Grzywacz, Professor Emeritus of the OSHA National Training Institute, “Most utility accidents and fatalities with respect to line contact are a result of lack of appropriate PPE, lack of insulated line cover up, or lack of appropriate grounding.”
3. Select the Right Equipment for the Job
Grounding Components: When building sets, you can choose from a variety of electrical grounding components. Because grounding components (cables, ferrules and clamps) are furnished to meet the needs of various applications, each must meet the maximum current that could flow through the completed set at any time. As a general rule, your equipment is only as strong as the weakest component. For example, if one component is a grade 2 and the rest of the set is equipped to meet the current flow of a grade 4, your grounding equipment is rated at a grade 2.
Clamps: In addition to ensuring that all components meet the fault current requirements for the job at hand, consider the clamp style and cable length. Under fault conditions, grounding cables can whip violently. For this reason, select clamps based on what they will be clamped onto to avoid fly off. Stocking grounding sets of various cable lengths is advised. Cabling that is too long creates an added hazard and could cause further injury, additional damage, or worse.
Check grounds for breakage at clamps. If damage is found, remove the cable from use immediately and send it for further inspection. Check cable for any flattened or smashed sections. Wire brushing should occur before and after use to remove dirt and corrosion.
Cable Jackets: Cable can be purchased with colored jackets or clear. Colored jackets, such as yellow, can offer better visibility of the ground set. A clear jacket provides better visibility to the copper stranding within, making damage inspection easier. Ground cables are stated in American Wires Gage numbers (AWG) and are also classified by type. Specifications for temporary grounding equipment can be found in ASTM F855-1990.
4. Oversee Regular Cleaning and Storage
Regular cleaning of ground sets prolongs the life and safety of the set. Several factors can reduce a set’s effectiveness or contribute to its demise. Dirt and water can actually conduct electricity. The everyday, petroleum-based products that grounds come in contact with can damage the integrity of the ground set and reduce protective properties. Wire brushing of the ground clamps to remove corrosion and dirt, as well as cleaning the grounding cable with a rubber goods cleaner, should be done immediately before and after each use. Don’t forget to wire brush the cable that the clamps will be attached to. Proper cleaning also allows for better inspection of the equipment and may reveal damage that would have previously gone unnoticed.
When sending grounds for recertification or repair, a professional facility will take the time to remove all corrosion and dirt from the ground set. Your set will look brand new and provide peak performance. When storing ground sets, keep them in a protective ground set bag. As with all safety equipment, store sets in a temperature-controlled environment, out of direct sunlight and high humidity.
5. Conduct Daily Inspections
Before each use, inspect clamps, cables, support studs, shrink tubing and ferrules to ensure that there is no structural damage. Clamps should be free of loose parts, sharp edges, splits and cracks. They should be able to be operated smoothly by hand (see ASTM F855-09, 10, 23, 36). Carefully inspect the area where the cable meets the ferrule for any breakage. Then begin inspecting the cable jacket for any corrosion (indicated by swollen or soft spots), flattened or smashed sections, or any cuts or breakage in the cable jacket. Any damaged ground set should be taken out of use and sent for repair and recertification.
While damage can sometimes be easily identified, regular wear and tear, extreme voltage, and moisture can all cause unseen damage. For this reason, follow industry best practices and establish planned repair and recertification intervals based on the type and frequency of work.
6. Manage Maintenance and Recertification
Broken and damaged grounds should be sent in for repair and recertification. It is highly recommended that ground sets without seemingly obvious structural damage also be sent to a certified test lab for regular recertification. Certified test labs completely disassemble and clean each component, including ferrules, clamps and cable. Each is tested separately per ASTM standards.
Any necessary repairs or replacement parts are made as the device is reassembled. Then the complete ground set is tested. Once the ground set passes testing, it is labeled with test dates and due dates for recertification. This keeps crews in the loop about upcoming test interval expiration dates. The complexity of the recertification and repair process requires highly skilled and experienced personnel. It’s no surprise, then, that the industry trend is moving toward having an experienced testing laboratory complete these processes.
If It’s Not Grounded…
Proper electrical grounding keeps you compliant and ensures that you remain safe while working on the line. Remember, a line that is de-energized can easily become energized in the blink of an eye, so stay safe and safely grounded at all times. If it’s not grounded, it’s not dead!