I got a great suggestion for an article from one of my readers last month. He asked that I talk a little about safety around overhead wires. Sounded like an electrifying topic.
As a master electrician with 15 years in the trade, I was taught that all overhead wires must maintain a certain clearance from the ground, over decks and swimming pools, etc. The National Electrical Code specifies these minimum heights, such as 10? above a deck. That height protects most people from unintended contact with live wires. It does not protect a pressure wash guy using a 24? telescoping wand to wash a house, however. Ten feet of clearance does nothing to protect a person in a bucket truck, either. In fact, it might not even protect a guy on the ground using an X-Jet to wash a house. In any of these cases, a life may be in danger.
Sometimes people believe that overhead lines are insulated so they are ?safe?. Actually, in spite of their appearance, many older overhead service lines and all high-voltage lines are not (or not fully) insulated. The distance between the lines is the primary reason why they don?t spark, but a conducting wand placed half way in-between two lines could cause a massive electrical ?jump?. Newer electrical services with three or four wires all wound in a group are adequately insulated in spite of the bare wire ? which is actually a? neutral? with no voltage on it. Even when you are looking at an insulated overhead line, why would you take a chance by getting close to it?
Buildings are served by electrical voltages that are, by definition, the most frequently fatal to come into contact with. Voltages under 600 kill many times more people than all high-voltage lines. If you think about it, these lines are almost everywhere we might go as contractors.
Electricity will jump some distance in order to find a path to ground. When that path to ground includes our heart, the result is usually fatal. Electricity can go in one finger and out another on the same hand with little consequence. If it goes in your hand and travels down to your feet to the ground, you are in serious trouble ? all in a millisecond.
Electricity can be conducted through metal, water, wet non-conductive surfaces, trees, plants, or even nearby people. You might be surprised to learn that ordinary tap water is a conductor. Pure water is actually not a conductor, but water that contains ordinary salts or chemicals or any impurity conducts electricity rather well. That includes water from a hose or even rain water.
We are unique as a trade because we use water every day and we use several different wands and telescoping poles in the course of cleaning. We don?t usually think of our work as dangerous, probably because we do similar jobs every day without dying. Problem is, however, it only takes one inattentive moment to change everything.
So how can you protect yourself? Rubber boots and rubber-soled shoes are a logical place to start. They won?t protect you if they are all wet, however, so you can?t rely on just them for total protection. Fiberglass ladders are better than aluminum ones, but a wet fiberglass ladder is just as dangerous as a dry aluminum one. Better protection comes from good habits, like careful observation. If the person bidding the cleaning of the building makes a notation on the bid sheet pointing out the location of overhead lines and the electrical service location, for example, it would naturally bring these things to the attention of the person going out to do the work. If electrical dangers were mentioned regularly during safety meetings, employees would be more likely to look around for these dangers when they get to a job.
If a person has to use a telescoping wand in an area where overhead lines are present, the assistance of a spotter to watch out for moments when the wand is too close for comfort could save a life. As a rule of thumb, you always want to maintain several feet of safety distance.
These days a lot of contractors are using pumping systems like the Roofster to shoot cleaning solutions on roofs. This low-pressure washing system is a great profit generator. A stream of cleaner or rinse water that shoots 40? to a rooftop is efficient for cleaning roofs from the ground, but it also can create an electrical hazard if accidentally aimed at power lines.
There are several electrical dangers beyond overhead lines, too. One example is an electrical outlet near an area being cleaned. Most outdoor receptacles are protected by a GFCI circuit or device, but not all of them are. GFCI?s are intended to cut off the power within milliseconds of detecting a path from the hot wire to ground (an electrical shock). Outdoor outlets installed prior to 1974 are not necessarily protected this way, and protection may not exist if someone has tampered with an outlet. Beyond that, sometimes these safety devices just simply fail. Better to be safe than sorry, and keep water spray away from any electrical outlet. That includes porch lights, switches, etc. Many contractors teach their employees to cover outlets with plastic to protect them.
Another frequent danger spot is for kitchen exhaust cleaning. In that field, we deal with rooftop fans as well as lighting circuits in the hoods. Precautions like lockout systems must always be the rule in KEC.
One final point ? use caution with electrical tools and electrical cords. Frays or cuts in wire insulation can be danger points. Most new power tools are double-insulated, but using a drill while standing in wet shoes on the ground is an invitation to disaster. Follow the safety guidelines that come with every power tool.
We are water-friendly people and sometimes we forget the danger that water can add to any ordinary everyday situation. Be safe out there!