I have a question regarding 2008 NEC 314.27[A], Outlet Boxes, which states...
"Boxes used at luminaire and lampholder outlets in ceilings shall be designed for the purpose and shall be required to support a luminaire weighing a minimum of 50 lbs."

Does this mean that the familiar round old-work boxes that are supported by the drywall ceiling with clamps are allowed to be used only for supporting lightweight, non-lighting related items, such as, smoke detectors, etc…?

I have heard this before, but am wondering if this is actually enforced in old-work situations?

Thanks

You understand correctly.

A look at the UL White book will reveal that 'new construction' boxes are rated for 50 lbs, while the 'old work' boxes are rated only at 6 lbs.

With such a difference in design criteria, I suspect enforcement is what you call it whan any but the lightest fixtures fall out.

Good news, 314.27(A) doesn't prohibit ceiling fans!

Sure ... but elsewhere we are told to use only ;fan rated' boxes for fans. I have something of a problem with this, as the traditional steel box screwed to a solid lumber brace you've installed has no such official rating.

Well, that's what proposals are for ....

I'm just thinking back over the years about the dozens and dozens of fixtures that I have added and installed using these old-work boxes. I can’t remember ever installing a fixture that weighed more than a couple of pounds on these, let alone 6-pounds, but I guess I could see someone else who didn’t know any better, coming in behind me and installing some 18-pound drywall-breaking behemoth at a later date.

I don't think anyone with even limited trade knowledge or common sense would attempt to install a heavy fixture on one of these boxes, but apparently the NEC is concerned that the homeowner, handyman, maintenance person or other unqualified individual will do just that. Probably similar as to the reason why we now need to have handle ties on all multi-wire branch circuits... to protect the unqualified individuals who have no business doing what they are doing anyway.

Much of the code is about handyman-proofing electrical installations

As long as they sell books and materials aimed at the homeowner, unqualified installers will be a reality.
Even the penny pinching national builder my wife worked for spec'ed fan boxes for all ceiling outlets, even some that would not have room for the blades of a fan like a water closet.

NEC exactly that, NATIONAL. Check the forums,Some places all you need to do is pronounce the word electricity, And suddenly, Your an EC.

That's why I like Massachusetts (one of the VERY few reasons):
527 CMR 12.00- Rule #8.
That is, You need a license,certificate of insurance or a signed waiver from the customer acknowledging they know you don't have insurance.To pull a permit.

Also MGL Chapter 141: Pretty much seals the deal.

Along with the usual Government business forms and taxes etc.

However, some Inspectors will allow Homeowner permits,for 'public relation' reasons (BOOO !!)

My Goof: law reads: (in short) MGL chapter 143 sec.3L.
"...No person shall install for 'Hire' any electrical wiring or fixtures subject to this section with out first given notice to...."

So i guess Joe can Burn his own house down. (Boooo)

It would seem to be unAmerican if a land owner didn't have the right to maintain his own property in the cradle of liberty. It would make you want to go down to Concord and shoot some redcoats