HOT STICK TESTING
Electricity – it scares most people, but if you work in the industry, you know that with the correct training and PPE the job is safe to perform. Part of this is the correct tools. Today I will discuss the hot stick. Power lines are generally 20 feet or more in the air. This makes it harder to accidentally contact these lines. But when you must work on them, how do you reach them and do so safely? Hot Sticks are the answer used most of the time. In the past, these were made from wood, but today these are typically made of fiberglass reinforced with epoxy. This is the same construction used on many small boats and the body of the Chevy Corvette and the extra-wide wheel covers on “dualie” type pickup trucks. Some hot sticks are fixed length; some are telescoping; some have hinges on them.
Most common for hot sticks today is to have a universal attachment head – this allows you to attach hundreds of different types of tools to the hot stick, depending upon the need. Some of the attachments are hooks of different types to allow for disconnecting and removing of fuses or disconnects, hand tools of many types, and even chain saws to clear brush from power lines. Some have fixed attachments – this includes “shepherds hooks”, or rescue hooks, to pull someone from direct contact with the line voltage without you becoming part of the problem. Most hot sticks have a round cross-section, but recently I have seen some with a triangular cross-section. I would think this is much better because you can put more torque on the hot stick to rotate the attachment without your hands slipping on the hot stick.
Hot sticks should be calibrated every 2 years at a minimum, or anytime the operator feels the “tingling” of voltage propagating from the high voltage line or if the hot stick appears damaged in any fashion.
We follow the practices listed in ASTM F711 (Standard Specification for Fiberglass-Reinforced Plastic (FRP) Rod and Tube Used in Live Line Tools) when doing hot stick testing. Hot Sticks can be used without gloves or other electrical safety gear, so it is important that they do not conduct electricity. Before a hot stick is used it should be cleaned and wiped down with a silicon-impregnated wipe. When you bring your hot stick to us, we will log it into our system first. The unit is then cleaned. It is important to remove any potentially conducting residue from the hot stick. A visual check is then made to see if any mechanical damage has been done to the stick. If no damage is apparent the unit is waxed. If damage is apparent, then the damage must be fixed, or the unit might need to be scrapped. This step is important so water will bead-up on the stick rather than forming a film that can easily conduct the electricity from the line to the operator. Now the unit can be electrically tested: this involves putting a high voltage (100 kV/foot) on the hot stick and testing the whole length of the hot stick for 5 minutes while monitoring to ensure the leakage current is not too high. Once this test is passed the unit is removed from the test rack, checked again for any visual damage that might have occurred during the testing, marked for calibration date, and staged for shipping.
visit our laboratory today, to see our equipped facilities to help provide electrical safety in the place of work through a proper high voltage hot stick testing.