Anyone who makes their living by working with electricity quickly develops a healthy respect for anything with even a remote chance of being "live." Yet the pressures of the getting a job done on time or getting a mission-critical piece of equipment back online can result in carelessness and uncharacteristic mistakes by even the most seasoned electrician.
This list was developed as a quick reminder of what not to do when taking electrical measurements. Paying attention to three specific categories when thinking about the most common mistakes made when making electrical measurements, personal protective equipment, tools, and culture of safety.
Personal Protective Equipment (PPE)
Having the right equipment to keep you save comes first.
1. Leave your safety glasses in your shirt pocket.
Take them out. Put them on. It's important. The same goes for taking the time to put on insulated gloves and flame-resistant clothing. All of these steps fall under wearing proper PPE. Follow the table method to figure out what level of gear you need on, as detailed by NFPA 70E Standard for Electrical Safety in the Workplace.
2. Work on a live circuit.
De-energize the circuit whenever possible. If the situation requires you to work on a live circuit, use properly rated tools paired with the correct PPE for the environment. Make sure you wear safety glasses or a face shield and insulated gloves, remove watches or other jewelry, stand on an insulated mat and wear flame-resistant clothing, not regular work clothes.
Once you’re geared up and you’re appropriately protected, it’s just as important to make sure the tool in your hand is the right one for this situation, and the test tool and its accessories are safe to use.
3. Replace the original fuse with a cheaper one.
If your digital multimeter meets today's safety standards, that fuse is a special safety sand fuse designed to pop before an overload hits your hand. When you change your meter fuse, be sure to replace it with an authorized fuse.
4. Use the wrong test tool for the job.
It's important to match your digital multimeter to the work ahead. Make sure your test tool holds the correct CAT rating for each job you do, even if it means switching DMMs throughout the day.
5. Grab the cheapest meter on the rack.
You can upgrade later, right? Maybe not, if you end up a victim of a safety accident because that cheap test tool didn't actually contain the safety features it advertised. Look for independent laboratory testing marks on your test tools to ensure they have been proven to handle what they’re advertised at.
6. Neglect your leads.
Test leads are an important component of digital multimeter safety, they are an extension of your test tool. Make sure your leads match the CAT level of your job as well as the tool. Look for test leads with double insulation, shrouded input connectors, finger guards, and a non-slip surface.
7. Hang onto your old test tool forever.
Today's test tools contain safety features that were unheard of, even a few years ago. Even if your old test tool is still working, many of the new features, both safety and test features, can be well worth the cost of an equipment upgrade.
Culture of Safety
How your company thinks about and learns about safety influences how individuals conduct their work, what the culture of safety around them looks like. Mistakes are made when you’re pushed to work too quickly or new employees aren’t properly trained.
8. Use a bit of wire or metal to get around the fuse all together.
That may seem like a quick fix if you're caught without an extra fuse, but that fuse could be all that ends up between you and a spike headed your way.
9. Fail to use proper lockout/tagout procedures.
Remember to follow the correct steps to remove power from an electrical circuit or panel, and to lock out and tag the panel or circuit, so that no one can re-energize it while work is in progress. Lockout/tagout procedures are detailed as part of NFPA 70E.
10.Keep both hands on the test.
Saved a big one for last on this list: do not keep both hands on the test. When working with live circuits, remember the old electrician's trick to keep one hand in your pocket. That lessens the chance of a closed circuit across your chest and through your heart. Hang or rest the meter if possible. Try to avoid holding it with your hands to minimize personal exposure to the effects of transients.