A Safety Tip to Help Avoid Electrocution
Anything from a chain link fence to a campground pedestal box can have a dangerous contact voltage. Here’s a simple tip to help keep you safe…
Everyone,
I began apprenticing with a master electrician when I was around 12 years old. Our local VoTech instructor Lloyd May taught residential wiring, and since my dad was a teacher in the same school system, he hired this master electrician to install some extra circuits in our basement. I asked if I could help with the wiring and was instantly hooked on the wonders of split-phase 120/240-volt AC power.
But before Lloyd would let me get anywhere near a live electrical panel he made sure I understood some basic safety procedures. Yes, we pulled the main fuse block and metered the panel to be sure it was off, but these safety tips are universal when working around anything that could possibly have voltage on it.
Safety First…
I was standing on a wooden chair, not the damp basement floor.
He made me put my unused hand in my back pocket so I wouldn’t be temped to grab onto the metal box with it, creating a possible hand-to-hand current fault path.
Lloyd showed me to use my knuckle or single finger to first touch anything that could possibly be energized, rather than use the flat of my hand. And here’s why…
Your hand has more muscles to make a fist than to open your fingers…
You can try this out for yourself. Your hand is designed to grab onto things with a lot of strength, not open up with great force. Sort of like the jaws of an alligator that can be held shut with electrical tape.
If you touch an electrified object with an open palm, the muscles in your hand will make a fist and you can’t let go…
And this is a bad idea since you won’t be able to let go of the electrified object, no matter how hard you try. I’ve had this happen to me a few times, and it’s terrifying. Lucky for me the first time it happened there was someone nearby to turn off the power. The second time I was able to use my body weight to pull myself free. But once the fault current reaches 20 mA or so, all the muscles in your body will contract and you just can’t let go. And if you can’t get free quickly enough, your heart may go into ventricular fibrillation (VFib) and you could die by electrocution.
Always check every metal object possibly connected to power with your knuckle or a single finger first.
If it’s electrified your hand will tend to jump away and disconnect you from the fault current, possibly saving your life…
Now, I don’t advocate using this technique to replace a voltmeter or Non-Contact Voltage Tester to check for a live circuit, but I tend to do this on door knobs, metal boxes, chain link fences, scaffolding, microphones, and anything else that’s anywhere near AC power. And this tip has saved my bacon a few times when my hand jumped back and disconnected me from the shock hazard. I don’t ever want to experience not being able to let go of an electrified object again.
Let’s stay safe out there… Mike
I worked with/around medium and high voltage as a startup engineer. Great tutorial! I was also taught to have someone nearby with a wood or fiberglass pole to push me away if something went wrong.
Very simply, from a physiology aspect, an electrical impulse causes muscles to contract. So, in addition to a knuckle of a closed hand feeling a current, that same current will cause the muscles in the arm to contract, thus pulling away from the source. Same with heat, use the back of your hand to see if objects are hot, like doors and doorknobs in the event of a fire. Never want to open a door with a fire on the other side!!