Smart Media Player Network Access in Fedora 20

[Tim]

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.

-- 
tim at localhost ~]$ uname -rsvp

Linux 3.16.3-200.fc20.i686 #1 SMP Wed Sep 17 23:07:44 UTC 2014 i686

All mail to my mailbox is automatically deleted, there is no point trying
to privately email me, I will only read messages posted to the public lists.

George Orwell's '1984' was supposed to be a warning against tyranny, not
a set of instructions for supposedly democratic governments.