Arch Flash Analysis
An Arc flash hazard study determines the available incident energy and protective device clearing time during an Arc Flash event. It provides a recommendation of Personal Protective Equipment (PPE) which is required to provide appropriate personal protection.
Q: What is Arc Flash?
A: An Arc Flash is the result of the flow of electrical current through ionized air after a short circuit condition or flashover from an energized source.
Q: What hazards does Arc Flash present?
A: Arc Flash can create the following negative results:
- Extreme level of radiant heat resulting in severe burns.
- Loss of hearing as a result of the sound blast caused by the arc fault.
- “Shotgun Effect” caused by the vaporization of metal and debris which is distributed by the explosion.
- Blast pressure waves from the force of the explosion.
Q: What is an Arc Flash Analysis?
A: An Arc Flash analysis is an electrical engineering study performed to determine the available Arc Flash potential and appropriate Personal Protective Equipment (PPE) as well as to comply with OSHA, NFPA 70E, NFPA 70B, IEEE, and NEC code requirements.
Q: How do we implement an Arc Flash Hazard Program?
A: Once an Arc Flash program is implemented, it is essential that a ongoing program is established.
The first and most critical step in performing an Arc Flash analysis is data collection. The personnel performing this task on the facilities electrical infrastructure must be properly trained and equipped with the appropriate Personal Protective Equipment (PPE). Once this data is collected and documented, a system model is built. In order to develop an accurate Arc Flash analysis, a Short Circuit and Coordination study is preformed.
Short Circuit Current Studies are performed to determine the level of incident energy which may be present during a short circuit or fault condition. This study will determine the following:
- Fault current throughout an electrical distribution system.
- Determine whether the existing equipment is rated correctly and can withstand the available fault current.
Coordination Studies are performed to determine the “clearing time” of protective devices as well as ensure a properly coordinated electrical system. This study will determine the following:
- The appropriate trip settings in protective devices to allow the electrical system to trip in a desired sequence during a fault condition.
- Isolate a problem area from the remaining electrical distribution system
- Ensure that all of the equipment is adequately protected and minimize system damage.
Q: What Personal Protective Equipment (PPE) should be worn?
A: The results of an Arc Flash analysis will determine the appropriate (PPE) such as flame retardant clothing, gloves, eye protection, etc. As part of the study, Arc Flash Labels are installed on the appropriate electrical equipment designating the level of Personal Protective Equipment (PPE) required as well as approach boundaries while the equipment is energized.