Ideally, work on electrical lines and equipment is safely conducted with the power off. However, this is not always feasible. As a result, live line work is commonplace for those in the electrical power industry. It is imperative that workers follow very specific safety procedures, wear the appropriate PPE and use the correct live line tools in the proper manner.
Live line tools provide electrical insulation between high-voltage lines, workers and other sources of electricity. At the same time, they always maintain a minimum approach distance from any energized lines or equipment. These tools may include hot sticks, sectionalizer kits, insulated links, rescue hooks, discharge hooks, insulating hand tools, cutter sticks and shotgun sticks.
Live line tools are not intended to be used on lines of No. 6 copper, No. 6 ACSR, No. 8A copper-weld or smaller, unless continuity of service is absolutely necessary. In the event live line work is deemed necessary, the proper authorization is required prior to beginning work.
Additionally, only clean and dry synthetic ropes should be used when working on energized lines or conductors. Link sticks can be used between energized lines or conductors for all voltages. Workers should avoid using live line tools in adverse weather conditions, such as thunderstorms, high winds, snowstorms, ice storms or days with high humidity. These conditions make energized conductors and equipment more volatile and hazardous to work on.
Before using any live line tools, OSHA requires a visual inspection of each tool to determine if there is any obvious damage or wear. Observed defects may include bent, worn or cracked components; evidence of tracking; deterioration on the fiberglass-reinforced plastic rod; the presence of dirt, paint, creosote, grease or other foreign materials; or a tingling/fuzzy sensation when in contact with energized conductors or equipment.
If a defect is discovered, a tool should be tagged and removed from service. Whenever tools are repaired or refinished, they must be deemed safe through a retest before use. Live line tools should only be used if the employer approves.
Tools must also be clean and dry prior to use. In the field, use a silicone-treated cloth to wipe down hot sticks and other live line tools or PPE. Doing this applies a layer of silicone film to the tool to prevent moisture buildup and contamination. More thorough cleaning can be conducted periodically with a special all-purpose cleaner and a soft cloth or sponge.
Once tools have been thoroughly cleaned, a fiberglass wax should be applied to maintain a glossy surface. This is required on live line tools in case they are used in wet or rainy conditions. The glossiness will ensure moisture beads up and prevents water from having a blanket effect on the tool’s surface.
Live line tools should be tested, at minimum, every two years. If the tool’s integrity is found to be compromised, it must be tagged and removed from service. Testing can be done with a hot stick tester, which is intended to perform wet and dry tests.
Tools should also be dielectrically tested at the beginning of each job and shall be tagged out of service in the event of failure. The leakage current may not be greater than 1 microampere per kilovolt (kV) of nominal phase to ground voltage. If there is something wrong with the equipment or the leakage is greater than 1 microampere per kV of nominal phase to ground voltage, workers should immediately stop working and alert their supervisor. It is not safe to resume work until the problem is located and repaired, and the tool passes a boom-current test.
Avoid laying live line tools on the ground or leaning them against sharp objects, such as barbed wire fences. Instead, use special racks, holders or tarpaulins (a cover that tools can be laid on to prevent contamination). When live line tools are not in use, keep them in a specifically designed canvas bag or weatherproof container and store them in a dry and warm place.
Although these tools do not completely eliminate the risk of electrocution and shock, when properly used and cared for, they can greatly reduce it.