I am involved in energy efficient lighting upgrade projects.
So I am dealing with existing wiring- extending the wiring into the fixture is usually not an option- and also undesirable because it is old wiring and probably is not the correct temp rating to be next to a ballast.
What do you think of the following situations:
1. Taking down an existing surface mounted 8ft fluorscent and replacing with same- the existing fixture is supported at one end by a hickey thru the ceneter of the outlet box- making a 4" hole in this situation would require breaking open the ceiling to provide an new support. Does the supported solely by the box cover this- it is supported at one end by the box.
2. 2ft fluorescent fixture (W44) about 4" wide barely covers the outlet box. A 4" hole would be the full width of the fixture and surely weaken it. Can I get away with the supported solely by the box rule if I want to add extra supports directly to the wall at each side to make secure. Fixtures are installed in schools where vandalism is a problem.
3. Highhats. Existing recessed high hat can- we remove the can and install a surface wrap fixture over the opening and connect the lamp whip directly into the back of the fixture. The highhat slice box is above the ceiling as it always was.
I can understand the reasons for the code change but should there be an exception for existing wiring conditions. Rewiring the building is not an option in these projects.