The old saying “close only counts in horseshoes and hand grenades” also may apply to the philosophy of working with live energized lines and equipment. Nevada-based NV Energy decided years ago that the safety benefits of working on energized equipment from a distance of 6 ft or 8 ft was worth the loss of dexterity or control. And, the company's linemen have proven that they now can pretty much do anything with a “hot stick.”
Working on live lines is nothing new. Baked wooden poles were first used in the 1920s to help replace fuses and move live lines away from equipment that needed to be repaired. Today's linemen can use specially treated fiberglass poles that can do everything from testing voltage to tightening or removing nuts and bolts. They also can rely on hot sticks to tie conductor wire to insulators, open and close switches, and install connectors and terminals though gunpowder-activated power tools.
Although working with insulated gloves directly on live wires and equipment is an option in the industry, NV Energy's linemen prefer to use hot sticks. This provides them with the benefit of being a few feet removed from the potential of an inadvertent arc of electricity or “second point of contact,” which can happen when a lineman accidently touches energized equipment with a non-gloved part of the body.
All of these live-line-work strategies are intended to help utility customers stay in service while equipment is replaced or repaired and to get the most customers back in service as soon as possible after a storm or other damage to equipment.
For example, NV Energy linemen see more than their share of vehicles wrapped around utility poles in Las Vegas. Often, such accidents disrupt service to hundreds or thousands of NV Energy's customers. Once the problem is identified, power can be routed around the problem area or the line can be re-energized. Through the use of hot sticks and other equipment, linemen can replace the pole or make the repairs without shutting down the service and impacting electricity reliability. This is especially important during the summertime, when temperatures can soar to more than 115°F and customers are extra reliant on air conditioning.
Such car-pole accidents happen several times a week in Las Vegas, and hot sticks in the trained hands of NV Energy linemen help keep electricity flowing and customers cool.
Storing and Maintaining Hot Sticks
To reduce restoration times and safely work live on NV Energy's system, the linemen ensure that the hot sticks are in top operating condition. The utility tests the dielectric properties of the hot sticks yearly through an in-house program. Technicians spray the sticks down with water and then run a machine over the wet sticks to measure the hot stick's ability to conduct even small amounts of electricity. This testing results in a pass or fail outcome for each stick.
NV Energy technicians also look for any scratches in the hot stick or any problems with the multiple tool attachments that might need fixing. All of that work is done in-house with standard fiberglass repairing techniques and making sure all of the individual tool mechanisms are working properly. Because the hot stick is such a critical tool for NV Energy linemen, if one happens to be inadvertently dropped from the top of a pole or from bucket truck height, it is immediately discarded for safety reasons.
The hot sticks are stored in specialized compartments within the bucket trucks. When NV Energy specs its vehicles, it orders them with separate areas for each hot stick. These storage areas were traditionally lined with a felt or rubberized lining, but most new trucks simply have holders made from plastic piping. The larger bucket or boom trucks have about 15 to 20 hot sticks on board, and the smaller foremen rigs have about three or four hot sticks at the ready.