Arc flashes are one of the most dangerous incidents to occur in any electrical installation. This type of electrical explosion, although rare, can cause serious harm to the people involved, from major physical injuries to even death. It can also permanently damage surrounding equipment and cause long downtimes.
Arc detector systems, like ABB’s TVOC-2 Arc Guard System, can detect light radiation and essentially provide an extra layer of safety to your personnel and equipment. This guide explores how the TVOC-2 can provide arc flash protection for your assets.
What Causes an Arc Flash?
Arc flashes are caused by released energy between a live conductor and another conductor. The reaction produces discharge of intense light and heat powerful enough to be fatal. Many factors can contribute to an arc flash, including bad connections, human error, and other external factors.
However, the most common trigger of an arc flash is poor maintenance of electrical equipment. If an electrical assembly has large electrical machines, the chances of short-circuiting are high. Faulty wiring, overloaded circuits, or loose connections could interrupt the normal flow of an electrical current and allow it to jump between conductors in a gap of air, causing a blast.
An arc flash could last until the voltage powering it is completely depleted, and until the heat from the overload is gone. It can be extinguished in mild cases or in more open facilities, but chances are slim. In the event of an arc flash, prevention is always better than cure.
Why is an Arc Flash Dangerous?
We know that an arc flash explosion can be deadly, but what are the precise implications of this event? The following are just some of the dangerous effects:
- Exposure to Extreme Temperature
The arc flash blast heightens the temperature to extremes, going up to 2000°C. The extreme temperature erodes any surrounding insulating materials, producing fumes and expelling molten material, which all lasts until the flash has completely died down.
The force of the blast could also propel projectiles in the surrounding area, severely injuring anyone within the vicinity. The extremely heated metal could cause third-degree burns on human skin, and the combination of steam and radiant heat could cause burns typically associated with burning liquids.
- Hearing Damage
The impact of an electric arc mimics that of an actual explosion, and any person within range of the blast could be exposed to sound levels reaching up to 160 db.
When coupled with brute force and a sudden pressure wave, it could damage the eardrum badly. There is a high risk of temporary or even permanent hearing loss.
- Physical Injuries
Aside from burns and hearing damage, other severe injuries may be incurred from the blast. Any stray projectiles could hit critical and most susceptible body parts, like the eyes, which could result in irreparable damage.
- Inhalation of Toxic Gases
The fumes generated by burning insulating materials and molten or vaporised metals can be toxic. These fumes result from incomplete combustion and consist of carbon particles and other solid substances suspended in the air. When inhaled, this could affect physical health.
How the TVOC-2 Arc Guard System Can Help Protect Your Assets
In order to combat potential arc flash flares, assemblies can be equipped with both passive and active forms of protection. Active protection can help limit internal arcing through light arc detectors such as IPD and ABB’s TVOC-2 Arc Guard System.
The TVOC-2 Arc Guard System is an optical arc flash mitigation device that can instantly detect the light from an occurring arc flash for easy prevention.
Benefits of the TVOC-2
- Safety and Protection
The TVOC-2 works with the current sensing unit, CSU-2, to measure any overcurrents in the assembly. In the event that it detects a trip, the TVOC-2 will immediately signal the system breaker and cut the power feeding the arc before it overloads and causes an arc flash. This is also beneficial for system maintenance, as it easily identifies the fault location for repair.
Both the TVOC-2 and CSU-2 can connect to the cloud through a COM hub or Ekip E-hub, allowing remote monitoring of both equipment, to ensure complete safety of personnel.
- Easy Installation
The TVOC-2 is efficiently designed to promote easy installation and expansion. It can use up to 30 optical detectors with a range of supported cable lengths, from one metre to 60 metres. The unit can hold up to 20 supervised sensors, fit for any business case.
Although the TVOC-2 already comes with HMI or HMI-COM units, its intuitive design allows for an easy upgrade or even installation of another unit. Using HMI-COM, any detected anomalies are sent to a remote station using Modbus RTU. The system also uses Rogowski coil technology on open-loop sensors for easier retrofitting.
Overall, the configuration of the main unit can be done in minutes, with professional installation services included.
- Ensuring Continuous Operation
To ensure that the TVOC-2 only trips during an arc flash, the CSU-2 adds current detection as a second condition to the system. This keeps the TVOC-2 from detecting any false triggers.
With both the TVOC-2 and CSU-2 on the job, the system can minimise total tripping to 1-2 milliseconds. Within these two milliseconds, the trip data is already being transmitted via fibre optic cables, only leaving the breaker open for a total of 30-50 milliseconds. This mitigates overall damage to the switchgear and guarantees safety for the personnel.
As mentioned previously, the Arc Guard System uses Rogowski coil current sensors. These sensors can be made to retrofit old switchgear, reducing downtime from installation. The sensors can be easily added to busbars and conductors to keep the system up and running in no time.
The Rogowski coil technology also enables a faster reaction time with a wider range of current measurement. Its speed rivals any conventional current transformer in the market.
Prioritise Safety for Arc Flash Prevention
While arc flashes may be a rare occurrence, the possible damages to people and facilities are far too high to risk. ABB’s TVOC-2 Arc Guard System is part of a range of comprehensive Critical Power solutions from IPD that can protect your assets.
Don’t wait for an arc flash to happen, prevent the loss of vital materials today by partnering with IPD. To learn more, get in touch with us at 1300 556 601 or visit our website.