Without tracking down previous editions of the code and referencing them, is anyone aware of a method to find out when a section of the code was adopted/amended? Example I saw today that brings this to mind: 3-phase 4-wire delta-connected panel. High leg was marked orange (good per NEC 384-3 (e) '99), but landed on C phase (bad per NEC 384-3 (f) '99). Don't know when the panel was installed but would say within the last 20-30 years. Was landing the high leg on anything but B phase ever acceptable (I'm sure it was at some point but that's that whole me assuming things problem). But the main question is when we are asked to “take a look at something” and it is to code but for one small thing, how do we figure out if it was acceptable at some point. I mean other than asking the question here.


Pete