Wouldn't the argument in case of the EMT in a groove be that if anything is below grade it needs to be at code-specified burial depth? Would be 80 cm around here in case of surfaces used by heavy vehicles, e.g. streets, driveways and car parks. Either run it above groundor bury it properly.
PS: of course red could have been chosen as a phase colour. In fact in most European countries nothing prevents you from pulling a red phase conductor in conduit and in fact both the French and the Swiss regularly do so! The Austrian regs do ban red conductors in cables and cords but I'm not sure if that's even still valid (the same article also bans grey and that's definitely been required rather than banned since the early 2000s).
Actually in most countries the regs. don't cover phase colours at all, only a few colours are not to be used - yellow, green, yellow/green and blue (the latter except in systems where no neutral is present, until recently that used to be in cables or conduit runs where no neutral is present). The only definite reference is in the manufacturing standards for cords and cables.
Plus there are exceptions - cords and cables with more than four conductors have black numbered conductors that may also be used as neutral conductors and there is or was a special German 6-conductor cable with three blues IIRC.
Last edited by Texas_Ranger; 05/07/15 07:57 AM.
