Arc flash for open/closed panel

[jado85]

I was looking at the new Arc flash labels, and noticed that 2 panels side by side one is missing a door have similar ratings, however one is missing the panel door and the breakers are visible.

This made me think, should there be a different Arc Flash label for open and closed panel doors?


Removed link by request

 

[zog]

Unless the gear is arc flash rated the doors are not considered to offer any protection as far as the Ei goes.

 

[jim dungar]

The door that 'hides' breaker handles is not one of the 'doors and covers' routinely addressed by 70E and OSHA.
The safety standards (e.g. NFPA70E task tables) care about the hinged doors and covers that allow contact with energized parts which in turn may affect the risk of causing an arc flash.

Of course there is the point mentioned by Zog, the presence or absence of 'unrated' enclosure openings does not change the calculated amount of incident energy.

 

[jado85]

I understand the available energy is not going to change. I saw something similar on a SWG that had and external door with HRC 2 rating and the internal door had A dangerous rating.

I guess my question is, say that I have a panel that has and HRC2 label is and not Arc Flash rated panel what level do I have to have the proper PPE for HRC 2?

1-out side the panel
2-opening the panel and exposing the CB?
3-removing the cover off and exposing the conductors and CB?

panel is similar to this one
http://www.eaton.com/Eaton/Products...boards/Lighting/Pow-R-Line3a/index.htm#tabs-2

 

[wbdvt]

The label would be on the outside of the panel to provide information on the incident energy level. That is the hazard portion. Another portion is the risk of an arc flash incident. That is why NFPA 70E-2015 has separated out the hazard from the risk. There is no HRC category anymore.

So, what does that mean? Basically, the hazard is identified, now one needs to determine the risk of that hazard. So,

1. Opening the door to look at the panel schedule - hazard is still there but the risk of causing that hazard for all practical purposes is zero unless the panel cover is being held on with one screw, then it fall causing an arc.
2. Operating a circuit breaker - hazard is still there as the breaker could fail but risk questions to ask are: Is the breaker maintained? Is there any unusual sounds or possible heat from panel/breaker? Was it installed according to the manufacturer's instructions? Are all the screws in the cover panel? Risk may be very low depending on the risk assessment so AR PPE may not be needed.
3. Removing Panel cover to expose breaker terminals, energized conductors/busbar - hazard is still there and now the risk of an arc flash is high, so AR PPE is needed.

 

[jado85]

The label would be on the outside of the panel to provide information on the incident energy level. That is the hazard portion. Another portion is the risk of an arc flash incident. That is why NFPA 70E-2015 has separated out the hazard from the risk. There is no HRC category anymore.

So, what does that mean? Basically, the hazard is identified, now one needs to determine the risk of that hazard. So,

1. Opening the door to look at the panel schedule - hazard is still there but the risk of causing that hazard for all practical purposes is zero unless the panel cover is being held on with one screw, then it fall causing an arc.
2. Operating a circuit breaker - hazard is still there as the breaker could fail but risk questions to ask are: Is the breaker maintained? Is there any unusual sounds or possible heat from panel/breaker? Was it installed according to the manufacturer's instructions? Are all the screws in the cover panel? Risk may be very low depending on the risk assessment so AR PPE may not be needed.
3. Removing Panel cover to expose breaker terminals, energized conductors/busbar - hazard is still there and now the risk of an arc flash is high, so AR PPE is needed.

Greatly worded, thank you!