Another example is when an owner has built a nice 2 story office building. He has tenants on the first floor,They are a doctor and an optician. So the owner decides to finish off the second floor and get more tenants. Now does he install wiring as per sec. 517 of the NEC or does he just install regular wiring. He doesn't know what type of tenant he will get for that second floor space. Ihave seen it done both ways. If he gets another tenant that needs 517 wiring, he will have to remove sheet rock and start all over again.
