Monday, September 04, 2006

Putting Your Life on the Line

Every day a maintenance technician, electrician, or even a homeowner puts their life into the hands of a voltage tester. Some are quick and easy to use while others have options that will never be explored. When you use a device to verify a de-energized circuit it is more important to make sure the verification is correct.

Lets look at a sampling of the testing unit variety available for our use. A lot of electricians have begun using a non-contact probe made by many manufacturers. These units are small, about the size of a pen, and easy to carry. The advantages of these units include the ability to detect the presence of electricity without touching the device. They can even sense the presence of electricity through insulation. But they depend on inductance and are only effective for testing alternating current circuits. These pens provide an indication of electricity and help diagnose circuit problems such as blown fuses. They are not the best option for verifying the ability to safely touch a possibly energized device.

Another small tester often used by many electricians is usually called by its nickname, a “Wiggy.” A more correct name for the device is a solenoid voltmeter. The unit uses power from the tested line to create a variable pull through an electrical solenoid which relates to the voltage sensed. Since the Wiggy directly contacts the circuit it is important to verify the Wiggy is properly rated for the circuit being tested. Are the device and test leads rated for the potential of the circuit? The Wiggy pulls a greater amount of current than most meters and can easily overheat if left connected to an electrical circuit. It too is a good indication of the presence of electricity but not a preferred method for personal safety testing of a possibly energized circuit.

The preferred method for testing an electrical circuit is the volt-ohm meter. It is supplied in varying designs by many manufacturers. Most of the volt-ohm meters measure the alternating current circuits using the root-mean squared value of the voltage. They can also measure and test direct current circuits as well. Generally a volt-ohm meter consumes very little power and provides little disturbance to the circuit being tested if power is present. As with the Wiggy, the user should verify that the meter being used for the test is properly rated for the circuit being tested. The most common meters are usually rated for no more than 600 volts and some of the better units are rated for 1000 volts. Many accidents happen when the user places the probes on medium voltage circuits such as 4,160 volt equipment which is much more power than the meter can withstand. Most often this mistake causes the meter to explode, severely injuring or killing the user.

Of course before using a volt-ohm meter you should make sure you are familiar with the operation of the meter and have read the user’s manual. Another test that helps insure the unit is providing correct indication is to test the meter on a circuit known to be energized. Of course this precaution is applicable to the non-contact and Wiggy meters too. Testing on a known circuit allows you to verify the meter and leads are in good working condition before you use them to verify a de-energized circuit where you will be putting yourself in harm’s way. This preliminary test is often skipped by many users and can easily lead to a fatal mistake.

As a final precaution you should make sure you are using proper personal protective equipment that would be necessary if the line were actually energized. Until the line is verified de-energized and properly grounded or locked out the user should always assume the line is energized. New regulations for arc flash and arc blast protection often frustrate the user when testing lines before verifying a de-energized circuit. But a few simple steps of precaution will allow you to remove the extra personal protective equipment and proceed with the job. Also never forget the possibility of other live circuits in the area where you are working. Examine the jobsite carefully and make sure you will be clear of these circuits or you will need to properly isolate those circuits as well.

Obviously we cannot cover all possible conditions in this brief thought provoking article. Hopefully this article will remind you to think the situation through before working on an electrical circuit. That moment of thought may save you from a severe electrical burn, shock, or death.

Thursday, August 24, 2006

When Things Go Wrong

Many experts on surviving an airplane crash will tell you that one key to survival is already knowing your escape route. After obtaining your seat count the rows to the nearest exit. If something does go wrong the cabin will likely be full of smoke and your only method of escape may be crawling on the floor. If you know the rows to the exit in front of you and the exit behind you then it may be easier to find your way out. This one example illustrates the importance of planning your actions for when things go wrong.

Life happens. And in the course of life we all eventually face a crisis. In fact most people have faced many crises. Planning for those events and presetting your state of mind for any possibility of the unknown may mean the difference between life and death for you, your coworker, family member, or friend. Planning may seem simple and you may consider most of your safety training as developing your plan. But if you check around you will find that most people don’t have a real plan. Presetting your state of mind is a more complicated concept and doesn’t mean living in fear of the impending disaster. It actually means learning how to keep a level head when the road is extremely bumpy.

Let’s examine the plan first. Do you know the best methods of escape from your workstation? If not, take some time and plan at least two methods of escape. The second method is your backup when the first is blocked. Do you know all the ways to summon help to your workstation? Check your company’s safety policy for their methods to summon help. Look for the nearest telephone to your workstation. Do you know the safest and quickest way to disconnect energy sources from the equipment in your workstation or in workstations around you? Know where to turn off energy sources in case someone gets in trouble near your workstation. If you have already looked at the alternative solutions to your potential decisions then you will be able to remain calm and make the right choices.

Having the plan ready takes one burden off your mind when things do go wrong. Maintaining a clear state of mind allows you to evaluate the choices and find the best possible solution. In some cases the solution may involve helping a coworker in need. In other cases the solution may be finding and using the quickest escape route and then summoning help. If you panic you will more likely make the wrong decision. In many situations it will be extremely difficult not to panic, but panic clouds your mind and causes your “fight or flight” reflexes to kick in. Fight or flight is your body’s method of using the quickest method out of trouble without consideration for wisdom. The adrenaline rush usually doesn’t help. Sometimes avoiding that automatic jump can actually lead to both a wiser and quicker solution.

Back to the plan. If you already know how you are going to react then even if some panic sits in you will be able to almost automatically make decisions. Thus you should rehearse your actions for potential situations. Your company probably already helped you with this rehearsal by way of fire or storm drills. You may have already taken some sort of first aid class or learned CPR. And most companies even allow you to use a fire extinguisher to teach you how and when to fight a fire, knowing that sometimes escape is more important than fighting a fire.

Many companies have employees that work on varying sites that may include unknown properties belonging to a customer or another company. Find out where you are going if you are going to be at a remote site. Look for the nearest emergency response team such as a fire department or rescue squad. Know how to summon help. You may want to write yourself instructions to keep with you while you are at the site.

In most emergency situations you will experience some panic. If you have already considered the unlikely but possible events then you will have more mental power available to analyze the situation and pick a planned solution. Having that advantage will reduce the stress which, in turn, reduces the panic and eliminates the illogical decisions that can be made in a fight or flight scenario.

Friday, August 18, 2006

Lock / Tag / Try

Most people working in a industrial facility have heard of a Lockout / Tag Out program. In fact you hear the term shortened to LOTO. But I would suggest a name change to this program. It should actually use the acronym LOTOTI which would stand for Lockout / Tag Out / Try It or shorten it to just Lock / Tag / Try.

Hopefully the equipment you are working with is labeled well or you are at least familiar with the sources of energy. Potential energy is the ability to release stored energy and in our case possibly cause bodily harm. Most people immediately understand locking out electrical sources, although they may not always follow the practice. Many people remember pneumatic sources (air lines) and are familiar with locking a valve closed. Some people remember mechanical sources such as springs or devices that can fall.

The proper method for locking out a device is something you should discuss with your employer. Your employer will provide you with approved devices for attaching locks, tags, and the actual locks. Your employer should also provide training at regular intervals to keep everyone aware of the potential hazards. Here I provide a few reminders to think about when you are about to work on a machine.

If you are locking out a machine all energy sources must be turned off or stopped. You then consider what potential energy sources can be “drained”. All energy sources must be secured. For example, you lower a lift or some vertical motion machine to its lowest position rather than using something to hold it in place. Another example is draining a pressurized line, pipe, or vessel. Once you have turned off the source of air or liquid in the line you find a safe way to release any built-up pressure in the line. Of course you can easy turn off breakers or place blinds in pipe flanges.

At this point you need to add an approved tag identifying you as having locked the device and when you locked it. Some manufacturers sell tags that meet regulations and include a spot to add your picture. The tag includes lamination that is added to the tag once the picture is applied. With a large facility sometimes it is easier to identify someone by picture before you recognize their name.

You isolated the energy source, relieved any potential energy, applied your lock and tagged your lock. Now we come to the part most people forget. Try to run the machine. Try to make the machine or device do what you do not want it to do before you put yourself in harm’s way. This final step is one way to assure yourself that you find the correct source of energy. Too many times someone has turned off energy sources, applied a lock, and applied a tag but not realized it was the wrong energy source. What if someone steps up to operate the machine without realizing you are in harm’s way? If they know the proper energy sources and don’t see the locks or tags they may assume it is safe to run the machine or device.

Remember that the machine used in your location may have specific instructions regarding isolating energy sources. Hopefully this article has provoked some thought about your work area. Always consult with your employer for the proper procedures.

Thursday, August 10, 2006

Look Before You Leap

In the world of safety terminology the direct cause of an incident is the energy released or hazardous material that caused the injury. An indirect cause is the unsafe act or condition that leads to the direct cause. When examining statistics for on-the-job injuries it will astound you how many times an indirect cause of the incident is not being able to see where you put your hands.

When you are at a busy intersection and about to cross the street, do you look both ways to make sure the traffic is stopped? How about a railroad crossing with no warning lights or barricades? Do you look to see if a train is coming? You wouldn’t drive down a curvy country road at night with no lights and your eyes closed. Why would you ever put such an important part of your body as your hands where you can’t see what will happen to them?

One of the biggest violators of this simple rule is electricians. The hazard is worsened by the electricians who do not use proper personal protective equipment such as electrically insulated gloves rated and tested for the voltages you may encounter. Reaching behind a wire and encountering a simple sliver of metal embedded in the wire can cause just enough electrical shock to fibrillate the heart if not an electrocution.

Another direct cause derived from lack of vision where you place your hands is spider or insect bites. Many times a mechanic might reach through a conveyor or other machine mounted above a pit in the floor. That pit, if not examined often or maintained, is a perfect harborage for poisonous spiders.

Let’s examine another situation often encountered by electricians. Cable trays are a very economical method to carry electrical cables between main power distribution points and motor control centers in various facilities such as paper and plastic manufacturing plants. Many times electricians reach into the tray to move a cable or examine a cable. They may be trying to move cables to make room for new cables. In this case the indirect cause, not seeing where you put your hands, causes an electrical shock to become an indirect cause. Often the shock does not have a chance to become the direct cause before the shock causes the electrician to fall and the impact on the floor becomes the direct cause.

Examine each situation carefully. Sometimes special tools can do the job and risk the hazard for you or provide the vision you need. Isolating the hazard means using proper lock, tag, and try procedures in most situations. In other cases your employer may provide a grasping tool to take the risk or mirrors to help provide the vision you need. Always use tools approved by your employer and make sure you use them properly. Is there a risk the tool will be grabbed by the machine and you still risk bodily injury? Did you check your personal protective equipment for integrity? Always examine the job carefully and make sure you can see the possibility for all the hazards before you risk bodily injury or even death. Following this simple rule will help you take home everything you intended to take home when you arrived at work.

Monday, August 07, 2006

Arc Fault Circuit Interrupters

A significant change in the National Electrical Code (NEC) took place in January, 2002 that will enhance the safety of your home. The NEC is a set of standards developed by the National Fire Protection Association (NFPA) adopted by most regulatory agencies. The Occupational Safety & Health Administration (OSHA) often uses the NEC standards to set their requirements for commercial and industrial establishments. It is likely that your local government regulatory agency such as a state or city electrical inspector also uses the NEC to set the standard for homes or businesses within their jurisdiction.

So what changed? The 1999 edition of the NEC set a deadline of January, 2002 for requiring Arc Fault Circuit Interrupters (AFCI) for receptacles in bedrooms. Most people want to know what an AFCI does compared to a Ground Fault Circuit Interrupter (GFCI). Well, hopefully you are already familiar with the GFCI since it has been required for various applications since 1971. The original requirement for GFCIs included outdoor locations and swimming pool areas. But today it has spread to include areas around swimming pools, hot tubs, spas, outdoor locations, bathrooms, garages, boat houses, kitchens, unfinished basements, crawl spaces, and wet bars. Of course there are some exceptions and you should probably consult a licensed electrician to understand the requirements and how they apply to your home.

So, let’s review the GFCI before we discuss the AFCI. Electricity always needs a complete path from its source to the destination and back to the source. That loop can either occur through various things including the ground and even your body. The electrical receptacle in the wall has at least two slots and hopefully at least three counting the ground. One slot passes electricity out of the outlet. The second slot allows the electricity to make the return path. The third hole or slot provides an alternate path we call a ground. The ground is intended to be more attractive for the electricity than your body if a primary path fails. But, let’s look at the two primary paths. A GFCI looks at the amount of electricity passing out one primary path and returning on the other primary path. If those two values do not match it must assume the difference is going where it should not go which might be your body. After enough difference is seen the GFCI will turn off the circuit. That amount is very small, approximately 5 milliamperes. But it is just below the threshold that will start causing damage to your body.

The AFCI is designed to protect you from arc faults, something quite different than a GFCI. Arc faults occur when the electricity is arcing randomly from a problem with the wiring. This arc is very hot but does not pull enough electricity to immediately signal a problem for the circuit breaker. The arc looks like somebody is welding and is often accompanied by the smell of ozone. An arc can reach thousands of degrees and easily start a fire without being recognized. In fact, the NFPA estimates 40,000 fires result each year from arcing faults. An AFCI has intelligence to recognize the random patterns of electricity used by an arcing fault and will open the electrical path under those conditions.
Today you can purchase an AFCI to fit inside your circuit breaker panel similar to the GFCIs designed to fit in your circuit breaker panels. In fact, other than function, they look similar. You will soon be able to purchase a combination GFCI / AFCI circuit breaker if they are not already available. Look for more changes in the code to require the AFCI in other applications as the technology develops. Hopefully you will never require the protection of an AFCI or GFCI, but isn’t it nice to know it is there watching out for you?

Sunday, August 06, 2006

A Moment of Safety

A moment of safety before beginning any task at home or work should be as natural as a moment of silence or a moment of prayer. Many of us remember to say a prayer or thank the one who prepared the food before each meal without any trigger other than sitting down to the table. We didn’t embed that habit overnight. As with any habit, bad or good, it took some repetitive training. In the case of the prayer before the meal perhaps our family injected the habit or even we forced it on our own until it became natural. We should build a similar habit into our every task or routine at both home and work.

When you approach any task do you pause a moment and take a look around? I’m not talking about a full 30 minutes or even 15 minutes doing a thorough inventory unless, of course, that is a job requirement. I’m talking about taking a couple of minutes to look around and see what might look different. Now the first couple of times you take inventory you may take a little longer to look and ask what might cause a problem in the task. But, as the job becomes more routine you will become used to what is normal and then be able to quickly identify what could happen.

Let’s look at some examples of this “moment of safety.” In the summer you may have a weekly habit of mowing your yard. Take a moment and look around the yard to see what might be in the way or cause a problem. Are there any children’s toys in the yard? Did somebody leave a rope laying out in the yard? I do hope you take a moment and check the oil in the mower and you probably take a peak at the gas level. Is there something else to see on the mower? Are the blades damaged? Are all the safety features in place? Do you have hearing protection?

Another example might be a floor or wall repair. You already have all the materials and tools you need. Are the tools in good repair? Do you have the proper protection such as goggles or gloves? Are there any hidden hazards a saw, nail, or screw may hit such as an electric line? Do you have somebody else around the house to contact if there is a problem?

Finally we look at the task that most of us see most repetitive and are not likely to use a moment of safety, your job. Does your workstation or area look any different than when you left it? Are all the devices you use in safe condition? Look for frayed electric cords, tripping hazards, new pinch points, or some place you may scrape your body. Do you know a safe route of escape if something goes wrong? Look towards your escape route and see if it is clear. What changed while you were away?
Take that moment and look around. It is short, quick, and most likely unnoticeable by anyone else. But that moment may be the most important moment of your life or even someone else’s life. It can be the one moment that takes the big negative life changing event out of your life or at least softens the blow. If that deterred event comes to pass not only will you be thankful, but both your family and employer will be thankful. Start the habit today. Take a moment for safety.