Enclosures & Arc FlashNo, your enclosure is not rated to contain an arc and therefore does not do anything to reduce the incident energy or arc flash protection boundary. The AFPB is defined in the 2009 edition of the NFPA-70E as a distance from a perspective arc source.
If you look in article 100 of 70E at the definition of arc flash hazard, FPN No 1 says that an arc flash hazard may exist when energized electrical conductors or circuit parts are exposed
or when they are within equipment in a guarded or enclosed condition, providing a person is interacting with the equipment in such a manner that could cause and electric arc. The handbook notes go on to explain that in certain conditions an arcing fault within the equipment could generate a pressure wave and destroy the integrity of the enclosure. The committee suggests that interacting with the equipment could mean opening or closing a disconnect, pushing a reset button or latching the enclosure door but that if the equipment is properly installed in accordance with the NEC, adequately maintained and operating normally the likelihood of these actions initiating a arc fault is remote.
In 130.7(C)(9) FPN No 1 says the collective experience of the task group is that in most cases closed doors do not provide enough protection to eliminate the need for PPE for instances where the state of the equipment is known to readily change and that the premise used by the task group is considered to be reasonable based on the consensus judgment of the full NFPA-70 Technical Committee.
If you search this forum there are several discussions on this topic; figuring out how to apply this in a practical manner has been fun.
See question #2 for an [url="http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=25973"]OSHA interpretation[/url].
There are several products available on the market to reduce the hazard to personnel and limit the PPE required. We don't use any of these products where I work but they were helpful in convincing people there is a real hazard here.
- [url="http://www.chickenswitch.com/"]Chicken Switch[/url]
- [url="http://www.utilityrelay.com/QUICK-TRIP_Page.html"]Maintenance Switch[/url]
- [url="http://www.remoterackingsolutions.com/"]Remote Breaker Racking[/url]
- [url="http://www.geindustrial.com/cwc/Dispatcher?REQUEST=PRODUCTS&pnlid=5&famid=40&catid=83&id=mvarcresist"]Arc Resistant Switchgear[/url]
- [url="http://www.geindustrial.com/products/static/switchgear/arc_vault.htm"]Arc Vault[/url]
- [url="http://www.moeller.net/en/products_solutions/power_distribution/power_communication/arc_fault_protection/index.jsp"]Arc Fault Protection System ARCON[/url]
- [url="http://www.irwindows.com/"]IR Windows[/url]
For info on DC please see this [url="http://www.arcflashforum.com/showthread.php?p=7123#post7123"]thread[/url] on the forum.