It was my understanding that when performing load calculations you must look at the wattage the light fixture is rated for and not the light you intend to put inside.
So, if the cans say "Max 75 Watt" then all the calculations should be done with that value.
This would address the statements above about new owners not liking the CF and putting in incandescent.
Anybody know if this is true?
The code
220.12 and Table 220.12 requires 3 watts per square foot for residential general lighting loads.
Footnote a of
Table 220.12 refers to
220.14(J) which says that in dwelling occupancies the specified lighting load includes the loads of general and other receptacle and lighting outlets specified in
220.14(J).
Therefore, the circuits and feeders must be adequate to supply 3 watts per square foot for all lights and outlets, regardless of the rating of the general lighting fixtures.
The often-stated "requirement" that the circuit may only be loaded to 80 percent of the amp-rating of the circuit is not correct. The only situation that requires derating of a general lighting and receptacle circuit is
if the circuit supplies a continuous load where the maximum load is expected to the continue for 3 hours or more. In that case, the overcurrent device (the circuit breaker) and the wires must be rated for the sum of the non-continuous load and 125% of the continuous portion of the load.
For example, one 15-amp circuit (1800 Watts) could permissibly serve all of the non-continuous lighting and general outlet loads in a 600 sq-ft room.
Notwithstanding the requirements, I would never put a 600 sq-ft recreation room on a 15-amp circuit. If known loads are greater than 3 Watts per square foot it would be stupid to put in circuits that are too small or too few.