3 Reasons to Think Twice
Loretta was excited but very nervous about her upcoming 20-week ultrasound; she and her husband, Vic, were told there may be complications with her pregnancy.
Their son Levi was now 5 years old, and all three had been hoping for a little brother or sister for Levi for two long years. This ultrasound was going to be a big surprise for Levi – he’d get to find out what his mom would be having.
Vic was traveling for work, but his boss agreed to fly him out the morning of the ultrasound so he could be with Loretta and Levi for the big event. The day before the ultrasound, Vic called Loretta to let her know that everything was going to be fine and that he would be home on an early flight the next day so he could be with her and Levi. Loretta sighed and thought to herself, “He used to have two reasons to think twice about what he did at work to make sure he came home safely; now he has three.”
That day, however – the day before he was to fly out – Vic’s crew had to isolate (de-energize) a power line and replace a section that was struck by lightning just hours before sunrise.
Vic had been doing this kind of work for more than six years, but neither he nor his crew had ever seen anything like what had happened. All three phases had completely disintegrated from the lightning, the aluminum fragments were incredibly brittle, yet the earth cable (shield wire) was perfectly intact.
There was a new apprentice working with Vic’s crew that day. Liz was a good apprentice, always keen to learn as much as she could by keeping a close eye on what the crew was doing. Vic’s crew was working from a switching program that was written and authorized by the night shift crew. Vic went over the switching program to make sure it was safe before they started switching.
Liz was helping Vic load the equipment in the bucket truck before he was to apply the portable earth device (temporary personal grounds), or PED, to the transformer side of the pole-top switch. She asked why they only had one set of PEDs to apply to the line. Vic was puzzled about why she would ask such a thing. Liz was always asking questions, and as she was still learning, not all of the questions were always relevant. This meant it was common to brush off one of her questions as not worth answering.
However, Liz was confident that her question was a legitimate one and wanted to know why only one set of PEDs was deemed suitable. Vic believed he had more important concerns in his life that day than to be distracted from such a hazardous task by pointless questions from an apprentice. His answer was concise and left Liz fully aware that he was not going to have time to explain every detail to her. Vic told her to step back so he could do his job.
As it turned out, Vic learned a big lesson that day – and wished he had learned it in a far better way.
The Next Day
Meanwhile, the next day – the day of the 20-week ultrasound – Loretta walked into the clinic with Levi following eagerly behind. Levi could not understand why his mom looked sad or why his dad was not there.
Loretta and Levi were called into the room for the ultrasound. Levi had been waiting for what seemed like his whole life to find out if he was going to have a little brother or sister, but his mom seemed unhappy as she was lying on the table. It’s no wonder Levi jumped with fright when he heard his mom squeal. Daddy had walked into the room! Levi jumped off the chair and into Vic’s arms, and Vic walked to the side of the table, kissed Loretta, squeezed her hand and apologized for being late. The plane had been delayed two hours due to bad weather.
The Value of a Questioning Attitude
So, what happened at Vic’s job site the day before Loretta’s ultrasound? The apprentice, Liz, had stood her ground and insisted that although she was not an experienced tradeswoman authorized to perform high-voltage switching, she knew that earths (grounds) are supposed to be able to withstand prospective fault current. The quick calculations in her head told her that 20 times the rated current of the transformer was nearly 80,000 amps. If the crew were to apply just one set of PEDs and a fault occurred, the cable would disintegrate like the aerials (phase wires) from the lightning strike – and they would lose all their protection.
Vic had never thought of that; in fact, none of the crew members had even considered it. All they had ever done was apply one set of PEDs, no matter where they applied them. As it turned out, they needed to apply four sets of PEDs at that one location to make the cable safe to access. Vic wished he had learned that in a much different setting. Instead, he was rude to an apprentice and could have been the cause of someone getting hurt if Liz had not had the strength to speak up when she thought something didn’t seem right.
It turned out every lineworker on-site that day learned a very valuable lesson; none of the electricians had ever considered the size of the transformer and the prospective fault current when using PEDs. Needless to say, no one gets annoyed anymore when Liz asks “too many” questions. They even push the other apprentices to ask a lot more questions. The more questions they ask, the more it makes everyone think twice about what they are doing.
The author of the switching program should have calculated the prospective fault current during the process of writing the switching program, and the checker (crew foreman) should have checked the calculations. It should never be left up to the operator on the day of the work to determine how many PEDs should be applied. It is also a requirement at many utilities to conduct a tailboard meeting to address any questions and/or concerns.
About the Author: Dale West is an industrial electrician and international high-voltage coach, trainer and speaker living in Australia.