I happened to be reading one of the recent "Electron" newsletters from the EWRB mailed out to us registered folks when this little pearl of wisdom stood out at me.
Apparently, to harmonise our cable ratings with those of Aussie, NZS 6401 will be revoked, this standard gives our building wiring cables (round and flat) their 600/1000V voltage rating, that is the maximum voltage between cores is 600V and between cores and earth is 1000V.
Now, under the new AS/NZS 5000:2:2006 cables will have a maximum voltage rating of 450/750V.
Now, I have some concern about this idea and I find it strange that there was never any consultation with those of us here that would actually be using the cables in question.
I've noticed over the last couple of years, the insulation on TPS cables is getting thinner, especially with composite (XLPE) cables.
It also makes me wonder if there hasn't been some sort of lobbying effort on the part of cable manufacturers in this issue, especially when you consider that cheaper imports are driving down the cost of cables sold in our DIY stores.
I'm only thinking about this from a safety aspect, if a new standard is introduced that allows a lower voltage rating and hence thinner insulation are we going to see more installations with damaged cables due to poor installation practice?
I agree that the 600/1000V rating is slightly over the top, but it has meant that we've had that bit more of a comfort zone in the past.
What's your opinion on this issue?.
Edit:Here's a link to the document (PDF) with the story in it:October Electron