Arc Flash Mitigation techniques - Elimination

By Cole Ferguson


Arc flash mitigation is important: to ensure the safety of a worker, every possible step must be taken to mitigate the arc flash hazard. Following the generally accepted hierarchy of controls, Elimination is the best way to mitigate an arc flash hazard.

De-Energize Equipment

When thinking about arc flash mitigation, this is the most straightforward way to eliminate an arc flash hazard. Simply de-energize all equipment that is being worked on. Without the possibility for current to flow, an arc flash incident cannot occur. All workplace electrical safety programs should stress that de-energizing equipment before work (such as maintenance) is a necessity. In order to ensure that you your equipment remains de-energized throughout the duration of the work and is not accidentally energized, you need to have appropriate safe working practices in place.

Lock-Out, Tag-Out

Lock-Out, Tag-Out (referred to as LOCO from here on out) is an excellent form of arc flash mitigation used to eliminate the risk of an arc flash incident occurring by ensuring that equipment remains de-energized while it is being worked on. LOCO requires that employees lock and tag the device being worked on so that it is impossible to accidentally turn the device on. The device can only be energized when all employees have removed their lock and tag and have confirmed that the device is ready to be energized again. This procedure does not work when it is necessary to perform work on energized equipment.

Remote Work

Sometimes equipment cannot be de-energized for work. When this happens, an arc flash incident cannot be eliminated entirely. With arc flash mitigation, what is most important is eliminating the risk of personnel injury caused by an arc flash incident. In this case it may be necessary to do work remotely. A few examples include:

  • Sensors can be added to equipment to monitor voltage, current, and temperature so that these readings can be observed on a computer instead of being observed by hand.
  • Switchgear can be closed remotely.
  • A remote racking system for racking circuit breakers will remove personnel from the arc flash boundary when inserting or removing breakers.

The best way to execute arc flash mitigation is to eliminate the hazard all together. You can do this by making sure equipment is de-energized for work using procedures such as LOCO. When it is not possible to de-energize, you can perform as much work as possible remotely using specialized equipment like sensors or remote racking systems.

This post is part 1 of the "Arc Flash Mitigation Techniques" series:

  1. Arc Flash Mitigation techniques - Elimination
  2. Arc Flash Mitigation Techniques - Substitution
  3. Arc Flash Mitigation Techniques - Engineering
  4. Arc Flash Mitigation techniques - Administrative
  5. Arc Flash Mitigation techniques - PPE