An arc flash is an electrical explosion or discharge from an appliance or equipment that is connected to an electrical circuit. It happens as a result of Low Impedance Connection in the electrical system, whether through air to ground, or through another voltage phase.
Low Impedance Connection is a point in the system that allows a high amount of low voltage current to pass through. This concentrated electrical energy then passes rapidly between conductors using ionized air as its medium. The result is a quick flash from an electrical item to the ground or another conductive object such as a human body. When an arc flash happens, surrounding temperature can go as high as 35,000°F.
A simple and less threatening example of an arc flash happens when an incandescent light burns out. But for larger conductors like conveyor belts or air conditioning units, an arc flash can cause burns, injuries, and even death.
Causes of an Arc Flash
An arc flash happens when two or more electrical conductors get too close to each other. The high currents in both conductors ionize the surrounding air, which allows electricity to jump from one to the other. In a circuit, foreign or unusual conductors can be introduced to the system by the following:
- Loose connection
- Accidental contact
- Damaged insulation
- Exposure of live wires
- Corrosion in conductors
- Obstructed disconnect panels
- Proximity of high voltage cables
- Dust, or other debris in conductors
- Improper installation tools and techniques
- Damaged electrical materials and equipment
- Moisture in electrical components or conductors
- Improper handling of switches, circuit breakers, or fuse
Knowing what causes an arc flash is the first step to prevent them from happening in your home or establishment.
How to Prevent an Arc Flash
1. Use the proper Personal Protective Equipment (PPE)
Personnel working with high voltage or risky electrical spaces should be wearing PPEs appropriate for the hazard level.
2. Use automatic or remotely operated Circuit Breakers
Circuit breakers are excellent safety measures against arc flashes. Still, manually operated ones are limited in terms of accessibility and responsiveness.
3. De-energize equipment before any maintenance or inspection jobs.
Another main reason for arc flash injuries is accidental contact with a tool or body part. Tripping the circuit breaker or switch is important for preventing this types of accidents during maintenance tasks.
4. Get rid of old – often unsafe – electrical equipment
Old equipment are prone to corrosion, damages, and debris. All of these are primary causes of arc flashes.
5. Regular conduct of preventive maintenance
Regular preventive maintenance helps prevent moisture, dust, and exposed wires to go unaddressed. Other issues can also be spotted in their earliest stages to prevent untoward incidents.
6. Only certified electrical professionals should be allowed to handle your electrical system
An arc flash is one of the reasons why only certified electricians and technicians should be allowed to handle repairs and maintenance of an electrical circuit.
Arc flashes threaten the safety of both electrical workers and regular grid users. Fortunately, there are reliable ways to reduce their occurrence and minimize the damage they could cause. You can start taking action today with these simple tips to safeguard your space from the dangers of arc flashes.
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