Can Anyone Describe an Arc Flash Event?

Mar 8, 2018
Hi everyone,

We have three phase Non-Segregated bus fault and it melted the bus. I am little bit confused about what is the meaning of Arc Flash fault. When we do the Arc Flash analysis, then we consider the Cubical door is opened and someone is going to change the state of the protective device. But if the door is closed and nobody is changing the state of the protection device and fault happens, can we say this is Arc Flash event? If yes, then we have to wear Arc Flash PPE as while you are close by Electrical Equipment as you do not know when Arc Flash event may happen. Can anyone describe about Arc Flash event?

I didn't find the right solution from the Internet.

Thank you.
Re: anyone describe about Arc Flash event?

<t>Most software packages that I have used do not allow for proprietary Bus Duct modeling. Some may offer this in their library. The bus duct model is different from a power cable model both in resistance and reactance, so using a cable model isn't recommended. The software packages that we use allows for a generic copper bus, and we have had good results that have been peer reviewed. <br/>
A maintenance contract with your service provider would allow you to request proprietary library models, we have used this service on several occasions especially when working with international clients.</t>

Ken Sellars

Staff member
Dec 30, 2016
Re: anyone describe about Arc Flash event?

<t>An arc flash event does not necessarily have to include human interaction. If an arcing fault occurs in the equipment, then you have experienced an arc flash. The severity of damage is based on multiple factors, such as available fault current, terminal or bus spacing, size and shape of the electrical equipment, etc. We have investigated many arc flash events that occurred when in fact no one was manipulating the equipment at the time of failure. <br/>
The question of required PPE is based on a solid hazard analysis and risk reduction technique. I know of many companies that require daily 8 calories per square centimeter arc-rated shirts and pants to even enter an electrical room. This is a proactive approach, as most electrical injuries are related to clothing fires. Normally, just walking by an electrical bus duct does not present a hazard, but IF, as employees walk by, a failure occurs, the potential for an injury could in fact exist. Your company must decide within its Electrical Safety Written Policy how to address these issues.</t>