Smart Media Player Network Access in Fedora 20

[Stephen Morris]

On 10/03/2014 07:13 PM, Tim wrote:
> On Fri, 2014-10-03 at 07:46 +1000, Stephen Morris wrote:
>> I'm in Australia too. The electronic store I bought the powerboard
>> from tells me that a 2000W room heater, which draws 8.3 amps, if
>> plugged in to a powerboard will weaken the surge protector and destroy
>> the circuits, which probably explains why the surge protector kept
>> tripping when the heater had been in use for some time.
> Bad advice...
>
> A surge protector does its work when the mains voltage goes above
> normal, and does *NOTHING* at other times.  When you plug devices into a
> surge protector, such as your telly, they are not drawing current
> through the protective device, your telly is connected directly to the
> mains, in parallel with the surge protector.  The protective device sits
> across active and neutral, and shunts any excessive voltage and current
> together, should the mains supply go high (a surge).  If the surge is
> high enough, the protection device will blow a fuse or circuit breaker
> (because they blow under high current conditions).
>
> Hopefully, it trips the breaker while the surge is building up, before
> it reaches a level that can fry other things on the circuit.  However,
> some devices, may be fried before a surge protector kicks in.  Your
> telly might not like being run on 255 volts (a surge above the nominal
> 240), but your surge arrestor might only activate at 260 volts.  They
> are a bit of a false economy, for that reason.  Our mains is nominally
> 240 volts, regulated to about +/- 10 volts, so all mains powered
> equipment must be able to run normally from 230 to 250 volts, at least.
> I've forgotten the specs for the range of AC voltage that the mains may
> surge up to without it being considered a fault condition, but some
> rather poorly built modern appliances don't cope with it, and most surge
> protected power boards don't kick in until *above* that point, too.
>
> The average surge protected power board doesn't really protect you
> against small (yet still destructive) mains surges, they're more
> designed to shunting seriously high surges that can cause fires in
> equipment (nearby lightning strikes, fallen power lines onto other power
> lines).  You'll probably still get wrecked equipment, but it'll go
> splat, and quickly finish, rather than catch fire and burn under a
> prolonged severe surge.
>
> You really want surge protection at the mains supply to the house.  Have
> everything protected, including all the wiring in your walls.  A large
> surge can burn all the house wiring, which can be catastrophic for the
> modern house which isn't all brick walls inside and out, but made from
> flammable materials.
>
> Simple surge protectors (as found in most power boards) can wear out,
> eventually.  You get lots of little surges on our mains, which take
> their toll, over the years.  You'll often see a little red LED on these
> devices, supposedly to show you that the surge protector is still
> working, and to tell you to throw away the board if the indicator LED
> has failed.
>
> What they can do is wear out circuit breakers.  Having an over-zealous
> surge arrestor continually shunting lots of current, means that the
> breaker is being stressed.
>
> These surge arrestor boards are really trying to solve a wrong problem,
> to use bad english.  Our mains can fluctuate, quite a bit, and every
> appliance sold on our market should be able to deal with that, on their
> own.  If your telly can't handle occasional mains spikes up to 270
> volts, for instance, it's badly manufactured.
     Thanks for the information Tim, it looks like I did get bad advice 
and the same guys have potentially given me bad advice in the last 
couple days again.

     I have had an issue with a wall double power point that has a power 
board plugged into each socket, where when there was a power blackout 
the red led on one power board went out but the red led on the 2nd power 
board remain lit the entire time of the blackout, when there is power 
into the power boards the red light is lit on both. This makes no sense 
to me if the wall socket is the same as that sold by the electronics 
store where there is only one connection point for the mains wiring, as 
with only one connection point how could one side be out and the other 
side be active in a power blackout? Also on a 2nd single power point 
recently installed by an electrician (the same electrician that 
installed our solar panels and replaced the complete fuse board in the 
meter box with a circuit breaker board) that I have a microwave plugged 
into, during the same power blackout the led display on the microwave 
remained lit the entire time.

     One of the guys in the electronic store told me that if I was 
getting those sorts of issues then the active and neutral points on 
those sockets were wired around the wrong way and that I should get them 
checked out asap because they could cause a house fire. I bought a 
leakage test device to check things out and it tells me that both power 
points in question are wired correctly, and when I tried the trip test 
on the device, which tripped a circuit breaker at 30 mA, the circuit 
breaker that tripped shut power off to every power point in the 
downstairs portion of the house including the power points in question. 
That indicates to me that everything is wired okay.

regards,
Steve


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