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
begin:vcard
fn:Stephen Morris
n:Morris;Stephen
email;internet:samorris@xxxxxxxxxxxxxxx
x-mozilla-html:TRUE
version:2.1
end:vcard
--
users mailing list
users@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe or change subscription options:
https://admin.fedoraproject.org/mailman/listinfo/users
Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
Have a question? Ask away: http://ask.fedoraproject.org
