When handled improperly, electrical hazards can cause serious injuries or even fatalities. And yet, many workers are unaware of the electrical hazards they work around day in and day out.
To keep these workers safe, employers must develop and implement a written health and safety program that takes into account the electrical hazards within the working area. This will include, but not be limited to, lockout/tagout procedures and electrical safety PPE (consult OSHA's 29 CFR 1910.37 in the United States).
Communication is also critical. Employees have a right to know all the hazards they face in the workplace and how to mitigate the risks posed by them. They also have the right to participate in creating the safety policies designed to keep them safe from electrical hazards.
Below are seven of the biggest electrical concerns in the workplace. Make sure that any employee working around these hazard has the training and preparation required to manage them safely.
1. Exposure to Electrical Parts
This is in some ways the archetypal electrical hazard. When people think of this category of workplace risk, what comes immediately to mind is electrical shock from coming into direct contact with energized electrical conductors or circuit parts.
To prevent electric shock and other injuries resulting from contact with electrical parts, safe work practices must be implemented and followed.
There must also be a system in place to alert people that they are in an area where the risk of electric shock, arc flash, or the failure of electric equipment parts is possible. Use the following alerting techniques:
- Display safety signs, safety symbols, and accident prevention tags
- Install barricades in conjunction with safety signs where it is necessary – these will limit access to hazardous work areas
- If signs and barricades are not sufficient, you can station a signal person near the hazardous area to warn or prevent employees from entering the area
2. Contact with Overhead Power Lines
Overhead power lines must be considered energized unless disconnected and physically grounded. When in the vicinity of overhead power lines, workers should not approach them or carry conductive objects unless the following is in place:
- The conductive object has an approved insulating handle
- The worker is insulated from the energized part by PPE with the proper voltage rating
- The energized part is insulted from the person and other conductive objects in the area
Work should not take place within 10 feet of live circuits above 50kV that are not barricaded or covered. The 10 feet limit includes not only the workers themselves but also hand-held objects or operating equipment. For higher voltage, greater buffer distances are required.
All overhead power lines need to be either barricaded or flagged whenever there is danger of contact with heavy equipment.
3. Wet Conditions
The severity of an electrical shock is determined by the amount of electrical current, the total time it spends flowing through the body, and where it flows in the body. A current as low as 23 milliamps can cause fatal respiratory paralysis, and 100 milliamps is enough to cause a fatality due to heart ventricular fibrillation.
Humid or wet conditions, including sweat on the skin, increase the potential for electric shock.
To protect workers in wet and humid conditions, you'll need a little extra planning. All cables and cords need to be kept out of the water. You can use scaffold stands to shield areas that have a potential for pooling water.
4. Using Damaged Tools or Equipment
To prevent electrical incidents involving damaged equipment, all instruments, tools, and machinery should be inspected before use. These inspections should include a visual inspection of all associated leads, cables, power cords, and connectors.
If there are any signs of damage or defect, the item must be tagged out and removed from service. It must not be used again before it undergoes repairs and tests to ensure that it is safe to use.
5. Circuit Overload
An electrical circuit system is made up of a breaker, wiring, and the device that requires power (that is, whatever is plugged into the outlet). Each device that is plugged into the circuit adds to the load to which the circuit needs to supply power. If this load exceeds the rating of the circuit wiring, it will trip the breaker and turn off all the power to that circuit.
If this happens on a regular basis, it is usually best to have an electrician look at the circuit to identify the issue and determine whether it is in need of repair or an upgrade.
If your circuit doesn't have a breaker, overloading it will overheat the wiring, which can melt the insulation and could lead to a fire.
Other telltale signs that you are overloading your circuit include:
- Light switches and outlets buzzing
- Outlet is warm to the touch
- Dimming lights or less power to tools
- A burning smell coming from outlets, switches, or tools
If you are experiencing any of these situations and you have checked your circuits to ensure there is no circuit overload occurring, contact an electrician to take a look at the circuit.
6. Improper Grounding
Grounding is a method of connecting an isolated conductor to some type of ground (a deep-driven ground rod is preferred) in order to trip or ground the circuit as quickly as possible.
Grounding by itself does not protect people from harmful shocks. However, it does act as a control measure. Improperly grounding electrical equipment increases electrical risks to workers.
To properly install a ground, start by connecting one end of the ground chain to a solid ground. The following are suitable for this purpose:
- The station ground grid in a substation
- The counterpoise ground at a transformer
- The neutral conductor on a distribution power line
- A transmission tower footing (ensuring that the ground penetrates the galvanizing)
- Down lead on a wood structure
The following are not considered suitable for protective grounding:
- A guy wire
- An anchor rod
If a ground rod is necessary, it should be a straight (not spiral) galvanized, copper- clad steel rod or temporary ground probe. It should be driven into the ground to a depth of at least 1 meter (approximately 3.3 feet) and a distance of approximately 10 meters (approximately 33 feet) from the immediate work area.
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Test the conductors that are to be grounded and establish that they are de-energized.
Using a hot-stick, connect the unattached end of the ground lead to the conductor.
Finally, secure the ground lead with rope so it won't cause harm by whipping if the fault current flows.
7. Damaged Insulation
Wiring with damaged insulation could mean a couple of things.
First, it may be due to the age of the wiring, in which case it simply needs to be replaced.
Second, it might indicate a much larger problem, such as an overloaded circuit that could result in a fire if it is not corrected.