Disconnect Switch to preclude opening panel door when energized

[lakee911]

I looked through the 2008 NEC and I am unable to find the answer to my question.

When do I need to have a disconnect switch on my control panel that precludes opening the door when the switch is closed (energized)?

Thanks,
Jason

 

[raider1]

I looked through the 2008 NEC and I am unable to find the answer to my question.

When do I need to have a disconnect switch on my control panel that precludes opening the door when the switch is closed (energized)?

Thanks,
Jason

You won't find that requirement in the NEC. That requirement would most likely be a product standard requirement.

Chris

 

[lakee911]

So, if I'm designing an industrial control panel, I don't need to necessarily include that feature from a code point of view?

Thanks,
Jason

 

[pfalcon]

So, if I'm designing an industrial control panel, I don't need to necessarily include that feature from a code point of view?

Thanks,
Jason

NFPA70 (NEC) barely covers industrial control panels. Should someone get hurt by your equipment then OSHA will ask you what standards you held. None is not a good answer.

I highly suggest that you adopt NFPA79:2007 "Electrical Standard for Industrial Machinery" which will answer your questions about good sound practices for building an industrial control panel.

The answer to your question would then be found at NFPA79:2007:6.2.3 and NPFA79:2007:5.3.1.4 stating that enclosure interlocking begins at 50 volts rms (alternating current) or 60 volts dc or more.

See the link below to preview the spec.
http://www.nfpa.org/aboutthecodes/list_of_codes_and_standards.asp?cookie_test=1

 

[lakee911]

I'll look into it. Thanks.

 

[edavis2293]

Purged Equipment

Purged Equipment

When we install equipment in Class 1 Division II locations and install a class Z purge to reduce the internal classification to unclassified, automatic disconnection of equipment inside the cabinet or equipment happens when the purge is lost. Some purge controllers have bypass switches to bypass the disconnection of equipment. These purge controllers also remain open until four changes of atmosphere have occurred in the enclosure after the door has been closed.

I know of no other requirement to disconnect power from a control panel in an unclassified location.