Well, I'll kick off the debate on SPDs. Once again, the emphasis seems to be on domestic (we all, or virtually all of us live in a home of one sort or another) so are the proposals an improvement or not?
I'd prefer something like a number from 0..10 based on the roughly estimated percentage of open space in the 1km square surrounding the property (parks, fields etc) - assuming of course that that's what the urban/suburban/rural disctinction is supposed to be about.
I've been pondering the same thing - I couldn't figure out why an urban area was 10x safer - it's not like thunderstorms avoid city centres (as far as I know). Similarly I'm confused by the criteria about the length of line between the consumer and substation - surely any distribution cable downstream of the consumer's tap off point will be just as an effective 'aerial' as that upstream.
I did wonder if the urban thing wasn't down to the lightning, but the number of other installations that were effectively in parallel with our own, so if each took a 'share' of the surge, any one installation would end up with a smaller share. I could perhaps be persuaded that there was 10x the amount of wiring per km² in urban areas than in suburban/rural ones. Complete conjecture of course.
I'd prefer something like a number from 0..10 based on the roughly estimated percentage of open space in the 1km square surrounding the property (parks, fields etc) - assuming of course that that's what the urban/suburban/rural disctinction is supposed to be about.
I've been pondering the same thing - I couldn't figure out why an urban area was 10x safer - it's not like thunderstorms avoid city centres (as far as I know). Similarly I'm confused by the criteria about the length of line between the consumer and substation - surely any distribution cable downstream of the consumer's tap off point will be just as an effective 'aerial' as that upstream.
I did wonder if the urban thing wasn't down to the lightning, but the number of other installations that were effectively in parallel with our own, so if each took a 'share' of the surge, any one installation would end up with a smaller share. I could perhaps be persuaded that there was 10x the amount of wiring per km² in urban areas than in suburban/rural ones. Complete conjecture of course.
