Cable Identification and Cutting Safety for Medium-Voltage Splicers
Robust cable identification and remote cutting practices aid utility organizations in protecting workers, preserving system integrity and complying with regulatory standards.
A medium-voltage underground splicer’s ability to safely and correctly identify, test and cut cable is more than part of their job; it is a survival skill. These splicers must be trained to make their first cut remotely – every time – whether performing routine maintenance or responding to an emergency, even when the cable has been tested and grounded. This approach ensures the worker is safely out of harm’s way if residual or unexpected energy remains in the system.
Procedural Development and Training
Proper cable identification supports operational efficiency, helping to minimize outages, reduce the risk of damaging cable and equipment, and expedite the restoration process after service disruptions.
Because misidentifying and/or improperly cutting a live cable can result in severe injury or death, utility organizations ideally develop and train employees on stringent cable identification procedures. Splicers must learn to use a combination of testing, grounding and electronic tracing to confirm cable identity before proceeding, regardless of the environment or circumstances.
Employers are legally required to comply with OSHA standards, which outline what they must accomplish to protect employees. Utility-specific guidelines also provide direction about how work is to be safely performed.
Layers of Defense
Cable splicing mirrors high-risk switching operations, which means that personal protective equipment is critical to worker safety. Standard PPE for a medium-voltage splicer includes a hard hat, safety glasses with side shields, steel-toe boots and flame-resistant clothing rated for the hazard exposure. Depending on the voltage and situation, a splicer may also need to wear rubber gloves, sleeves and arc-rated garments in exposed energized environments. Insulating hot sticks and grounding equipment are equally essential. Note that all PPE and tools must bear valid inspection stickers to confirm they are safe for use. The hazards of underground electrical work leave no room for shortcuts.
Lockout/tagout procedures offer another layer of defense. Once a cable has been identified, the splicer must work with dispatch to locate the nearest sectionalizing switches and isolate the line. Testing verifies the line has been properly switched out, and grounding removes any remaining induced voltage. Only then should a tag be placed on the equipment, clearly indicating that the cable must not be re-energized until the tag has been removed under the authority of dispatch and the worker who affixed it.
Modern electronic cable identification methods may not be available or reliable in some cases. Corroded grounds, damaged markers and other factors could force splicers to use traditional verification techniques, such as checking duct position numbers, verifying tags and footage markers, using blowers to feel air movement through ducts, and performing tug tests. Under no circumstances, however, should a snake be run through a duct unless the cable has first been proven de-energized.
Helpful Tools
Various advanced tools are available to help workers improve identification accuracy. Impulse test kits help to locate and phase identify direct-buried or conduit cables up to 20 miles long, including submersible cable. Using a transmitter that sends electrical impulses combined with a clamp-on receiver that reads the signals, splicers can accurately identify both single-phase and three-phase systems. Calibration and careful use of these tools are essential to prevent false readings.
Even with reliable identification tools, the process does not end once a cable is located and phased. Remote cutting is the final safeguard. No matter how certain the splicer is that a cable is de-energized, they must perform the first cut at a distance. Cutting implements can be selected based on the working environment. Grounded hot-stick cutters allow for smaller cable cuts from outside confined spaces. Bluetooth-enabled cutters can be operated remotely while secured in position to prevent accidental swings. Hydraulic cutters, with hoses and cords extending up to 40 feet, allow workers to stand clear of the cable during an initial cut. Regardless of the method, the objective remains the same: Keep workers out of the line of fire until the cable is fully severed.
The tools referenced here can help save lives – but only if they are in good condition. Follow manufacturer guidelines, store tools clean and dry in protective cases, and keep them shielded from unnecessary vibration and other exposures that could upset their calibration. With its constant bumps and jolts, a splicing truck is no place for delicate instruments unless they are properly secured. Dedicated, climate-protected storage ensures these devices remain reliable when they are needed most.
The Bottom Line
When it comes to cable identification and cutting, one principle stands above the rest: Treat every cable as if it is energized until proven otherwise – and maintain a margin of safety even then. By creating layers of defense with PPE, lockout/tagout procedures, proven tools and remote cutting, splicers safeguard themselves, their coworkers and the communities they serve. Underground cable work is largely unforgiving, but it can be performed safely and efficiently when approached with caution, precision and respect.
About the Author: Mark Savage is the owner of DeadBreak, a service-disabled veteran-owned small business providing underground distribution and transmission training, consulting and field services. A U.S. Marine Corps veteran with over 25 years of experience in underground construction and emergency response, Savage is a credentialed journeyman cable splicer/lineman and qualified medium-voltage splicing trainer. Reach him at msavage@deadbreak.us.