This seems like a silly question, but when it comes to protecting your electrical assets, you may not realize that you’re in a similar situation. We install airbags and hope we never need them, but they are there because we all understand that when needed, airbags can save lives.
We can all imagine what happens when there is no airbag to deploy but what happens to electrical equipment when there is no airbag equivalent, like an ultra-fast earthing switch (UFES)?
The UFES system is a combination of devices consisting of an electronic unit and the corresponding primary switching elements, which initiate a 3-phase short-circuit to earth in the event of a fault. It is similar to an airbag in that it is a low-cost add-on that remains passive, impacting nothing, until true need for it arises. Need for it is also unpredictable; just as you would prevent a car collision if you could predict it, you would also take steps to prevent an arc fault. Interestingly, a UFES and an airbag use similar technology to activate using a micro-gas generator, which allows for the device to change states, much like an airbag.
With an airbag people are protected, but not equipment. The vehicle takes the impact of a collision while protecting the human cargo inside, while a UFES protects both the equipment and the people by reducing the incident arc energy to nearly zero. It can also be added to an installation in the field and is replaceable once it has been activated, so if your installation is not protected, it isn’t too late to incorporate a low-cost addition that leaves you more protected.
And to stick with our car analogies, a UFES limits the damage to the equipment, turning a major collision into a small fender-bender. Usually, only a small amount of equipment will need replacing within the switchgear, so everything will be operational again with a UFES in a matter of days versus months, when a UFES is not fitted. In many cases, there will be no equipment replacement required at all, so that only a basic cleanup and replacement of the primary switching elements will be required.
An arc flash incident involves significant risk in terms of loss of life, loss of equipment, and loss of productivity. A person’s life could be saved in an arc flash incident simply by adding a UFES to the same equipment. The UFES meets current standards for fire safety NFPA 70E, which requires arc fault energy to be identified on equipment and limit access by roping off areas to personnel. A UFES lowers incident energy levels to the point where employees can access the gear without the same limitations such as personal protection equipment (PPE) or distance, making maintenance safer, simpler, and less costly.
The UFES system senses light and current. It uses these parameters to trigger its operation. The extremely short switching time in conjunction with the rapid and reliable detection of the fault ensures that an arc fault is extinguished almost immediately after it arises, within 4 ms of fault detection. For reference, a traditional airbag deploys at 30 ms, so a UFES is 7.5 times faster than the devices used in our vehicles. Inadvertent operation only occurs due to human error and even then, only the UFES need be replaced, since equipment damage only results from whatever triggers the fault event, not from the UFES itself.
Naturally, there is a financial saving to be made when damage is limited and equipment remains operational, but most importantly, maintenance personnel remain safe; a result that cannot be calculated in monetary terms. When you protect the system you protect your people too.
The article image is by Robert Kropf shared under creative commons license - the original can be found here