so if i run lighting to a pump house in an oilfield that is classified class 1 div 1 or class 1 div 2, then those ckts have to be intrinsically safe?
I don't think that it is even possible to have an intrinsically safe lighting circuit. For an instrinsically safe circuit there must be no possible way to cause a spark that has enough energy to ignite the gasses, even if you short the conductors. Lighting would have to be of the type approved for the area classification and the raceways and seals will have to comply with Article 501.
Don
