Can any one tell me which one is the article to be used when finding the rated ampacity of conductors and over current devices of a feeder for two or more branch circuits supplying x-ray equipment.
Here I find myself confused because both articles basically apply to the same condition.
517.73 Rating of Supply Conductors and
Overcurrent Protection
(2) Feeders The ampacity of supply feeders and the current
rating of overcurrent protective devices supplying two or
more branch circuits supplying X-ray units shall not be less
than 50 percent of the momentary demand rating of the
largest unit plus 25 percent of the momentary demand rating
of the next largest unit plus 10 percent of the momentary
demand rating of each additional unit. Where simultaneous
biplane examinations are undertaken with the X-ray units,
the supply conductors and overcurrent protective devices
shall be 100 percent of the momentary demand rating of
each X-ray unit.
I think the key word here is
