When an energized conductor or piece of equipment must be supported or moved for maintenance, line workers rely on insulated conductor support tools to keep them safe. These products insulate energized components from ground potential and other phases, making them a critical component of jobsite safety. This article provides the information you need to properly test, store, and maintain insulated tools for temporary conductor support.
Factory Testing for Insulated Support Tools
Prior to leaving the factory, support tools should be tested to the appropriate standards to ensure safety requirements are met. As an example, all CHANCE® hotsticks are subjected to the following before leaving the factory:
Insulated pole designed, manufactured, and tested to ASTM F711 and IEC 60855 standards
- 100% tested at 100 kV per foot as part of the production process
- Hotstick label is added showing the date the equipment was tested
- Variety of production lot testing, including electrical leakage after exposure to moisture, atmospheric wicking, dimensional verification, deflection, crush, and visual inspection
In-Service Testing and Maintenance Essentials: ASTM and Electrical Testing
To verify the equipment continues to perform as expected, it is essential to periodically test temporary support tools to ASTM and OHSA standards.
ASTM Testing:
It is recommended by power and utility experts that users follow the guidelines in ASTM F3121 to periodically test equipment. Specific details on the parameters for testing are included in the ASTM standard, but as a reference, the equipment should be tested to 75 kV per 12 inches under wet conditions. A high-voltage AC Hi Pot Tester or CHANCE portable wet/dry hotstick tester can be used during wet testing, but only with distilled water.
OHSA Electrical Testing:
Electrical testing should be performed once every two years, at minimum, per OSHA 1926.957(b)(3), as well as any time the insulating properties of the tool are in question. More frequent periodic testing may be warranted depending on how often the tool is used, where it is used, and how it is maintained. However, electrical testing is required before placing a tool that has been repaired in any way back in service. For accurate results, thoroughly clean the tool before testing. Do not use silicone or wax before electrical testing. A worn finish can produce a false positive result if silicone or wax are present on the surface.
What happens if equipment fails during testing?
Surface flaws on equipment can cause a failure during electrical testing. If surface flaws are present, determine if the unit can be refinished using a patch kit (H1917) or gloss restoring kit (C4001520) before discarding it. After refinishing, the tool must be retested per ASTM F3121 before returning to service.
Maintenance Must-Haves
In addition to periodic testing, insulated support equipment must also be carefully maintained over time. The list below provides essential maintenance actions.
- Keep the surface finish clean and glossy as it plays a critical role in the dielectric performance
- Inspect and clean equipment with silicone wipes prior to each use. For heavier contamination, Moisture Eater II wipes can be used before applying silicone
- Store in a bag, truck/trailer rack, or other protective storage after use to avoid physical damage, pollutants, and UV degradation
- If damage is found, or even suspected, the tools should be removed from service immediately
- If damage has resulted in exposed fiberglass, the tool must be destroyed
Summary
Insulated tools for temporary conductor support, such as hot arms, jib extensions, and three-phase lift assemblies, should be designed, manufactured, and tested to standards, and maintained just like a hand-held hotstick. When using temporary support equipment in an energized environment, be sure to also carefully follow your company’s work practices and procedures.
Want to learn more?
If you have any questions or would like to schedule a live-line tool training session with a CHANCE tools expert, please reach out to your local Hubbell Utility Solutions’ Territory Manager or fill out our training request form.
