[mythtv-users] Power Line Network Connections and Myth ?

Craig Huff huffcslists at gmail.com
Thu Sep 30 15:06:17 UTC 2010


On Thu, Sep 30, 2010 at 1:55 AM, Simon Hobson <linux at thehobsons.co.uk> wrote:
snip...
>
> That is no surprise - it's how 3 phase boards are generally arranged. Down
> each side, the circuits go L1, L2, L3, L1, L2, L3, ... Single phase circuits
> use one position and their loads get spread across the phases, 3 phase
> circuits are taken off one set of L1, L2, and L3.
>
> Having a 2 pole breaker like you have for 220V loads also means that if it
> trips, both sides of the supply are switched off - with 2 separate
> breakers/fuses, you could trip/blow one and leave the supply inoperative but
> still live. Worse still, if the fault were a short to earth on one side of
> the supply, the equipment might still be working (sort of, on 110V) using
> one half of the supply and earth !
>
See, this is why I'm not a teacher.... There's always something
seemingly insignificant, but important that I leave out. ;-)
Those 2 pole breakers are not two separate units.  It is a double-wide
ganged breaker that takes up two slots in the breaker box.  I haven't
investigated, but reason would suggest that they don't measure current
to neutral on each half of the 220 line, but rather the current across
the whole 220 service.  No possibility of limping on 110V!.
>
snip...
>
> And do radios still work - in your house, or elsewhere in the neighbourhood
> ? It's interesting to see that figure - just shows how "optimistic" the
> headline speed of the units is :-/
>
The commercial radio band works ok, but I haven't checked with any ham
radio operators and no one has started knocking on the front door (yet
;-)).

Craig.


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