[clug] Exercise and pay the bills! [SEC=UNCLASSIFIED]

[Brian]

On Mon, 09 Feb 2009 12:09:25 +1000, Steven Ring <smr at southsky.com.au>  
wrote:

> On Mon, Feb 9, 2009 at 11:09 AM, Roppola, Antti - BRS
> <Antti.Roppola at brs.gov.au> wrote:
>
>> Having watched line work on a few occassions, I note that they are very
>> hands
>> on when it comes to isolating and locking out lines. Due to the
>> potential
>> safety issues, I couldn't see them being in a hurry to trust automated
>> devices.
>
> Rightly so. I did a little investigation last year as to the
> effectiveness of anti-aliasing devices. Researchers in this area seem
> to rely on statistical analysis techniques to guage the probability of
> an anti-islanding device (based on voltage/phase analysis) failing to
> disconnect from the grid in the presence of other local PV systems.
>
> Present techniques don't seem to be 100% reliable, nor is there a
> standardised solution. So local power authorities are well advised to
> disconnect individual PV systems during a maintenance outage.
>
> Steven

Just to confirm that everyone is rightly paranoid about feed-in.
There are three breakers on my system, one at the metre box(this is the  
one actew turn off), one at the inverter and one near the actual panels,  
in case the firebrigade are on the roof.

Brian


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