What are the most common causes of electrical accidents?
When it comes to electrical hazards, protection relies on safe equipment, a safe environment, and safe work practices.
Today's employee works with or uses electricity directly or indirectly throughout the workday.
Because it has become such a familiar part of our daily lives, we tend to lose sight of the hazards that electricity poses.
Most electrical accidents result from three factors:
- Unsafe equipment or unsafe installation
- Hazardous environments or unsafe work practices
- These accidents can be avoided by using safe equipment, guards, grounding, circuit protection devices, and safe work practices.
Safety and Security Equipment
All electrical conductors and equipment in the workplace must be considered "acceptable." For a device to be considered acceptable, it must be marked as tested by a nationally recognized testing laboratory, and these marks will be sought on the device to consider it safe.
Equipment must be installed and operated within its designated capacity so as not to exceed equipment limits. For example, switching on the wrong switch for too large a load can cause overheating.
Matching equipment specifications with installation load expectations will help prevent damaging conditions.
There are many examples of such equipment, including:
- Ground-fault circuit interrupters (GFCIs) for waterproof appliances.
- Temporary power devices.
- Modular power devices.
- Motor control devices.
- Cable control, such as cable ties, conduit, tubing.
- Arc fault devices.
- Locking devices such as outlet locks and switch locks.
- Cable protection systems.
Guarding
Guarding involves positioning or enclosing electrical equipment to ensure that people do not accidentally come into contact with its live parts.
Effective guarding requires that equipment with exposed parts operating at 50 volts or more be located where it is accessible only to authorized personnel qualified to work on it.
Grounding
Grounding deliberately creates a low-resistance path connected to the earth.
This will prevent the buildup of voltages that could cause an electrical accident if a worker is in the ground path.
A properly designed grounding system creates a low-resistance path away from workers.
When properly designed, grounding significantly reduces the risk of electrical injury when combined with safe work practices.
Grounding is divided into two types:
Service or system ground or equipment ground.
Service or system ground is primarily designed to protect machinery, tools, and insulation from damage.
This is the neutral or grounded conductor, usually white or gray, which is grounded at the generator or transformer at the service entrance to the building.
Equipment grounding helps protect the operator by providing a secondary path for current flow in the event of a fault.
It will react faster to avoid shocks and serious injuries to the operator, and this is achieved through the use of circuit protection devices.
Circuit Protection Devices:
These devices automatically restrict or interrupt the flow of current in the event of a ground fault, overload, or short circuit in the wiring system.
Common examples include fuses, circuit breakers, and GFCIs.
Fuses and circuit breakers automatically open or break the circuit when too much current flows through them, melting or tripping to open the circuit.
They are slow-acting devices primarily used to protect conductors and equipment.
They generally do not open quickly enough to prevent shock or other injury.
They prevent overheating that would damage conductors or equipment.
GFCIs are typically used in wet locations, construction sites, plant maintenance, and other high-risk areas to protect equipment users.
These devices react much faster than fuses and circuit breakers to interrupt current flow before shock or injury occurs.
GFCI protection is provided in a variety of devices, including:
- Receptacles
- Detection units
- In-line cords
- Cord-set units
- Safe work applications
Electrical accidents can be largely avoided through safe work practices, such as:
- Disconnecting electrical equipment before inspection or repair.
- Lockout/tagout procedures to prevent accidental or unexpected operation of electrical equipment.
- Keeping power tools properly maintained.
- Being careful when working near live lines.
- Using appropriate personal protective equipment.
A lack of lockout/tagout procedures and the use of proper isolation equipment are major causes of unsafe work practices.
The first step before beginning any inspection, repair, or maintenance of any device is to follow a written procedure to isolate all power sources to prevent accidental startup of the device.
Only authorized and trained personnel should service electrical equipment. An individual lockout device must be issued to each authorized employee performing the activity, and no two lockout devices should be identical.
Authorized employees should be the only ones applying and removing their devices.
The responsibility for an electrical safety program should not be taken for granted but should be assigned to an electrician, electrical work practices, and appropriate standards for program management, and everyone is responsible for following the program to make it effective.