Warren Rogers holds up two sections of wires. You can’t tell them apart by looking at them, but he knows – one represents 120 volts. The other is 23,000 volts.
But that’s not the only difference.
“This one means an open casket,” he says of the “low” voltage wire. Of the high voltage wire, he says, "This one means a closed casket. That's the bright side.”
If that sounds like a scare tactic, that’s because it is. No one knows more about the deadly power of electricity than Rogers, and there’s not a better friend to police and firefighters. Rogers, safety administrator for Connecticut Light & Power, conducts lectures about scene safety for First Responders throughout the state. On March 11, he paid a visit to Haddam Volunteer Fire Company’s Station 1.
Rogers says the “no arc, no spark” rule is not nearly good enough – in fact, it’s downright foolhardy. He says emergency workers must be extra vigilant of their surroundings because even a wire that appears dead, or looks like it has an insulated sheath around it, is very likely still live and lethal. The only way to be sure is to have a CL&P utility worker telling you it’s safe, and even then, only he or she should move it.
Electricity feeds on humans because water is its best conductor, and we’re made of about 70 percent water. The simple science is that electricity (electrons) sees the ground, or earth, as an attractive place to flow because it’s positively charged.
Electricity is like water on the surface of a pond: It tries to find its level. If you make a hole in the surface of a pond the water will rush in to fill the gap; if you make a hill the water will flow outwards to level it out. The path isn’t only concerned about the ground. Electrons don’t know where they came from or where they’re going. They only care whether there is a difference in voltage from one place to the next. If there is a difference in voltage and a path for them to follow, they’ll take it.
So if a large tree comes crashing down, snapping a power line, the current will take the path of least resistance – a tree, guardrail, car or person. Burnt grass is often noticed the bottom of every post on an electrified guardrail.
Let’s go back to that electrified car. It seems to defy logic but people inside such a car are not being shocked. Death occurs when the occupant makes contact with that electrified car and the ground, which is why First Responders instruct occupants to stay inside the vehicle.
“It’s a tragedy when a life is lost, but it’s a double tragedy when a First Responder dies trying to save that person,” Rogers says. “That’s how I look at it.”
A person with no choice but to exit an electrified vehicle should cross their arms across the chest in an “X” pattern, for balance, put their feet together and hop away from the vehicle, avoiding simultaneous contact with the vehicle and ground. Once away, they can continue hopping or shuffling their feet to safety. Other than not contacting the vehicle, the important thing is to avoid taking steps, which can generate arcs.
What police and firefighters more often encounter is a downed power line. The Fire Company’s procedure is to stay a minimum of two poles away and out from under any live wire. First Responders are also advised to stay a minimum or 10 feet below a live power line due to the threat of arcing.
Here’s what everyone needs to know about power lines (see graphic):
Looking at your basic utility pole, the highest voltage generally starts at the top, at the “T” where the crossarms meet the pole. A static wire is the pole's top wire that bleeds lightning surges off the power lines during a storm. Primary wires (in a phase of three) carry electricity from the substations, usually at about 12,000 volts. A neutral wire below the transformer acts as a line back to the substation and balances out the load on the system. Secondary wires bring lower voltage electricity to the end user, typically in two 120-volt wires. A grounding conductor is a wire that connects the top static wire to the ground rod. You can recognize the grounding conductor because this wire runs the entire length of the pole.
To safely work around the house, Rogers recommends a simple device called a Ground Fault Circuit Interrupter, or GFCI.
He wants you to go buy the $10 part. Actually he wants you to buy five and give four away to friends. He all but guarantees that at some point, one of those friends will come back and tell you the GFCI saved his or her life.
GFCIs (different than surge protectors) help prevent electrocution by cutting off power before a person gets seriously injured. They’re most often found in areas where appliances may contact water, but Rogers said they should be used in conjunction with any plug-in power tool.
“Every spring I know my basement will flood, and every spring I’m down there with my wet vac, plugged into two GFCIs,” he says. “I’m not kidding.”
If you ever need to do work around wire, Rogers says to call CL&P first. They’ll schedule someone to come out – free of charge – to place protective plastic cuffs on the wires. When you’re done, call them back and they’ll come get them. If you have tree-trimming to do, Rogers says CL&P will temporarily cut off your power until you’re done.
“All we care about is that people are safe out there,” he says. “This is dangerous stuff and needs to be taken seriously.”