Each year, about 30,000 arc flash incidents happen due to electric equipment failure in the United States alone, according to the Industrial Safety and Hygiene News. As a result of these incidents, about 400 people die while 7,000 persons suffer burn injuries.
Arc flashes, also known as flashovers, are electrical explosion or discharges from a faulty connection, running through the air to ground or to another part of the electrical system. This energy discharge is displayed as a flash of light or a surge of heat.
The Harm that Arc Flashes Cause
Arc flashes can be caused accidentally by humans when a test probe is used incorrectly or a tool slips and comes into contact with the electrical grid. It can also be caused by sparks as a result of breaks in the insulation due to wear and tear, corrosion and impurities such as dust. Sometimes a piece of equipment fails, causing sparks to fly. Even lightning strikes can damage the grid system and cause flashovers.
Every situation that involves an arc flash is hazardous and could put the employees and the entire business in harm’s way. Arc flashes could generate temperatures four times the heat of the sun’s surface. The heat may vaporize conductors and other equipment, releasing poisonous gases that damage the lungs. Someone so much as directly looking at a flashover could impair their eyesight due to the flashover’s intense brightness.
For this reason, it is important to conduct arc flash assessments on power grid and other electrical systems to detect faults that could initiate arc flashes.
The Assessment Process
Understanding the potential for damage drives the necessity for an arc flash assessment by businesses. It could be a daunting task, but it is a cornerstone method to ensure safety throughout the system and a safe working environment for employees. Government standards demand that the analysis take place in a prescribed manner.
The purpose of an arc flash assessment is to determine the area and severity of the occurrence of an arc flash, accompanied by suggestions to minimize the likelihood of an arc flash happening. The process may be time-consuming, but it is vital to ensure that the electrical grid is as safe as possible. The following steps outline the process in arc flash assessment.
- Step 1: Gather data to determine the state of your power grid system. This can include knowing the minimum and maximum short circuit currents, details about protective devices, the specifications of conductor characteristics, motor impedances, states of the existing equipment, and voltages throughout the system.
- Step 2: Enter detailed data into a software program that provides you with a model of your system. All modes of operation need to be described including regular operation, operation with alternate sources of power, shut down of parts of the system, or other details that apply to your situation.
- Step 3: Determine the arching fault currents for each piece of equipment.
- Step 4: Identify the fault-clearing times based on worst-case statistics.
- Step 5: Determine the incident energy levels, based on environmental conditions at the time of the arc flash, and layout of equipment. Distances are specifically significant in this calculation.
- Step 6: Calculate the protection boundaries to determine the safe distances for your employees and the use of protective gear.
- Step 7: Apply lessons gleaned from the arc flash assessment. You can start displaying warning labels around power facilities and training your staff about how to avoid the occurrence of arc flashes and other electrical hazards. The lessons could also be applied to optimizing grid operations, modifying potentially hazardous the sections to increase safety. One important precaution against the harmful effects of arc flashes is to have employees wear personal protective equipment (PPE).
Get Help to Manage this Daunting Process
It is possible that you may have the resources and knowledge in-house to manage the arc flash assessment. But if the assessment seems overwhelming for your team, you can consider hiring an expert company, which:
- Has the appropriate software for the arc flash assessment;
- Has the up-to-date knowledge to conduct the assessment;
- Is knowledgeable in the latest government regulations;
- Are accredited providers of the service;
- Will make suggestions for improvement based on their extensive experience across many different situations; and
- Will provide training for your staff.