a The other day I noticed that a particular CD monitor's SUMPS is incorrectly wired - Active and Natural (sic) are swapped - there are over 5,000 of this particular type of CD monitor in Australia, and they have been in service since 2005. I mentioned this to a senior being today, whose first response was that it wasn't my concern, and I should just get on with my job. Surely, I said, any RECD's that are in end user facilities (the monitors are used in pubs and clubs), won't work properly as they will not be measuring the return current, and what happens if the fuse which is now in the neutral line blows, due to an earth short, this will leave the active wire exposed to someone rather than the supposedly lower return tied to earth. The answer ' I didn't make them, we just go with what they send us '. Interesting that despite the so called Australian electrical approval certificate which first time round is quite expensive and quite rigorous, the amount of commercial equipment that is installed without this approval and in some cases dangerously in the case of a certain coffee chain who insist that all their outlets are supplied with US equipment wiring, makes a mockery of the supposed tight safety regulations. I'm really fortunate that the 'senior being' has a restricted electrical licence - which is another one of my gripes about meaningless certificates and is IMHO a mthod of restricting trade to electricians only - my house wiring has it's earth connection via the mounting screws in light battens, and switches etc - the screw thread is just screwed against the earth wire piercing the flex, but no more. Colin -- cdb, on 11/16/2009 -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist