ECN Forum Forums Safety Discussion and News Occupational Safety Discussion 2011 NEC Section 410.130(G) Disconnecting Means.

Joe:
Back to your question.

Perhaps it's a numbers issue, as there are (on average) fewer fluorescent fixtures within a resi than comm?

The intent of reducing/eliminating a possible hazard to untrained (or under trained) unqualified persons would be the same in any location IMHO.

I still come upon the occasional jobsite where the 'factory' 'sta-con' connectors are cut off & laying on the floor.

Another issue is how is this to be enforced with replacement ballasts? Here the replacement is considered an 'ordinary repair' and no permit/inspection is required.

This "other than dwellings and associated accessory structures" wording goes back first to the Proposals for the 2005 NEC®. Back then, this 410.130(G) was numbered to fall into 410.79 and was ultimately designated as 410.79(G).

From the May 2004 ROP, Proposals 18-92 (Log #1780) from Craig Wellman and 18-93 (Log #3421) from Danny Liggett proposed this requirement, each with slightly different wordings.

The original wording in those Proposals was "other than dwellings and related/associated outbuildings".

For your question, a portion of the Substantiation to P18-92 (Log #1780) goes to the heart of your question:
"In commercial, industrial, institutional and government facilities, it is often unsafe or impractical to turn off power to luminaires at the panelboard. Turning off the power may leave a room in the dark or may reduce illumination, which in some cases can/could create work related hazards for facility occupants. ..."

So, reading between the lines, the distinction seems to be that dwellings and associated accessory structures are exempted from this luminaire disconnect requirement because:
• dwellings are not as large as those other occupancies to have as great a distance between panelboard and the luminaire being serviced
• rooms in dwellings generally have windows (for fire egress) that allow natural illumination whereas those other occupancies more typically include rooms without windows

No, the Code change itself was motivated by servicer injuries. This is noted in that ROP and ROC elsewhere in the Substantiations and in the CMP's Statements.