The Rule of Rules

Dave Smith has been an Industrial Maintenance Electrician since 1975. He has taught maintenance, troubleshooting and safety courses to thousands of electricians in mines, mills, refineries, factories, plants, power stations and offshore platforms throughout North America and the Middle East. Dave is a hands-on guy and teache...

As a rule, it seems, people like to make rules, then insist that their rules are the correct rules. Specifically, I’m talking about the “Left Hand Rule”. For years, disconnect handles were located on the right-hand side of switches while the hinges were on the left. So, we learned early to grab the handle with our left hand, position our body way off to the right of the switch, look away, hold our breath and close our eyes before very decisively moving the handle On or Off. This is the essence of the “Left Hand Rule”.

Several years ago, while teaching an electrical cross-training course to a group of instrument technologists, a student told me the “Left Hand Rule” had changed. You weren’t supposed to stand on the right side of the equipment, the student explained, but rather to the left, where you reach across the switch and operate the handle very decisively with your right hand.

I was stunned, because this “Right Hand Rule” puts your right arm (as well as a good chunk of your body) in close contact with the switch. (The rationale is that, should the switch blow up, the blown door will shield you from the flash.) When I heard this, I immediately went to our instructor group to find out whether they’ve heard the same thing. They were also amazed and, as a group, we completely disagree with this notion.

But this “Right Hand Rule” is still floating around out there. I just completed a class where the electricians told me they’ve had one manufacturer instruct them the old way, and another the new way.

It is important to differentiate between facts and opinions masquerading as facts. Fact: the traditional switching method puts our bodies out of the blast path. I have talked to a number of electrical workers over the years who have had doors blow open and none of them had been burned. I know of two workers, though, who broke bones in their hands and arms because they were in the way of doors being violently blown open.

Remember, there’s a ton of electrical ‘horsepower’ behind that door, just waiting to kick it open in your face. Many of us have seen the results of electrical explosions that have ripped metal doors right off their hinges when those ‘horses’ got their chance.

There are nine electrical instructors in our group with over 300 years of combined experience. We are grey, balding, wrinkled and weathered... and we’ve all been kicked. We don’t know everything, but here’s our two cents: stay to the handle side when the hinges are opposite the handle; when the hinges and handle are on the same side, then stay on the hinge side. For doors that have an operating handle in the middle, stay on the hinge side. In all cases, make sure you’re wearing your PPE!

If anyone reading this has bona fide evidence to the contrary, let me know and I’ll be the first to change my beliefs as well as my body positioning. Meantime, reaching fully across the front of any type of switch is just someone’s opinion—an opinion that could take your arm. It’s your body and your life, so plan your positioning carefully.

Until next time, be ready, be careful and be safe.