Cable Safety Considerations for Electric Utility Workers
Properly identifying energized cables is critical to worker safety. Over the course of my 30-year career, I’ve become aware of more than one cable splicer who suffered serious burns after attempting to cut into a live cable that was not properly identified or de-energized. Proper cable identification procedures may take some extra time on a job, but the cost of that extra time does not compare to the cost of a worker being injured and the aftermath that may follow.
In my experience, it’s not safe to cut any cable based on tags, chips, duct position, cable size, the word of an inspector or other splicer, or the proximity to the utility easement. Tools are available that reliably identify an exposed cable in a ditch. “Reliably” means the same as if we could walk, hands-on, from end to end to ensure we have the right cable. Always use a remotely operated mechanical or hydraulic punch on a cable before you cut it. In particular, if you can’t reliably identify a buried cable, you must punch the cable you are about to cut to ensure it is not energized. Workers must also be thoroughly trained on the operation of punches as well as on operating electronic cable identifying tools and analyzing their readings.
If there is any doubt about the status of a cable or cables to be cut, stop the job until clarification is made and everyone affected agrees that it is safe to continue.
I want to point out here that an amp probe is not a cable identification tool. It can potentially be used as a last resort retest, but it should never be used to perform the first or only test. Also, an amp probe is not to be used if you cannot receive a positive cable identification signal. Testing cables with an amp probe is a dated and dangerous method that should never be accepted.
Safely Disconnecting Cables
For the safety of everyone on the crew, the general steps for disconnecting any potentially energized cables must be followed. You may think of additional safety steps, but here are some that should always be considered:
- Follow the switching order/instructions given by the dispatcher. If you perform a step of the switching routine and the expected result does not occur, stop the job until it is safe to continue.
- Using an approved, functional tester, test the cable or cables to be de-energized.
- Once the cables are confirmed to be de-energized, place grounds using approved tools, testers and methods.
- Following your company’s operating rules, tag the cable ends with your company’s clearance or hold tags. Tags should never be placed on the doors or locks of pad-mounted or subsurface devices. They should be placed on the device to be operated.
- Maintain communication with the crew performing the testing to keep everyone aware of the different stages of testing and the conditions displayed on test readings.
- Positively identify the cables and have a crew member peer-check you.
- Clearly identify and mark the cables with a line/feeder number, the date and the initials of the people who identified the cable. This type of cable marking should be legible to anyone who may cut the cable at a later date.
- Cut the properly identified and marked cables with a remote cutting device. There are more than enough remote cutting tools to choose from. Select one and use it correctly.
Planning and Training are Key
We must do everything we can to prevent workers from being injured or killed. Nothing is more important than worker safety, but beyond the trauma and costs incurred, a company’s reputation and insurance ratings will suffer if a splicer is severely injured. If your company does not have robust policies and procedures in place for identifying and cutting operating cables – and the appropriate training for workers to understand and execute them – you should develop those now. Ensure that your crews are trained and effectively using the program for their safety.
In closing, we are putting thousands of miles of cable in the ground every year. The more we install, the more frequently we will have to repair cable. This means our cable operators must be prepared. If you’re not sure how to start building a cable identification procedure or plan, contact me and I’ll gladly help you regardless of where you work. I truly never want to hear about another splicer getting hurt when they unexpectedly cut into an energized cable.
About the Author: John M. Perez is a current member of IBEW Local 196 and a journeyman cable splicer. He entered the electric distribution field in 1991 as a cable splicer apprentice for ComEd. Since leaving ComEd in 2007, Perez has worked for multiple utility contractors in various states. He is currently the director of Quanta Underground Power Services.