Surge protection

[Humberto]

Does switching a wall plug to its off position, without unplugging the devices that are connected to it, protect those devices against surges through the power grid caused by (i) load shedding, and (ii) lightning strikes?

 

[Sinbad]

i) yes
ii) no

 

[Dark Agent]

ii) no

Really?
3. So unplugging is the best?
4. any alternatives to protect against lightning?

 

[Jet-Fighter7700]

so unplugging physically from the wall during shedding is a good idea then?

I heard that when the power returns, it goes very high, for a split second;

this is what damages things like fridges; and PC's,

how true is this?

 

[Sinbad]

Really?
3. So unplugging is the best?
4. any alternatives to protect against lightning?

Lightning doesn't always come down the live wire. The switch just breaks live.

Unplug. Or use lightning protection plugs and test regularly. Preferably unplug.

 

[Sinbad]

so unplugging physically from the wall during shedding is a good idea then?

I heard that when the power returns, it goes very high, for a split second;

this is what damages things like fridges; and PC's,

how true is this?

Not true.

What often happens is that the voltage is actually too low for a period due to inrush current everywhere.
What can also happen is that during the outage, a neutral bar is stolen from somewhere, then you end up with 400V steady.
Or, they flick the switch, it trips, they flick it again, it trips, flick it again, etc.

None of which is particularly good for your stuff

 

[Gnome]

I've personally tested with those Ellies surge protector plugs. They actually work really well. They are somewhat overpriced however IMO (Like R170ea from my local hardware store)

I just did a simple test using a relay. Without the surge protection there is a definite spike when power is switched. With the protector it is as if the spike doesn't exist, was really cool to see the difference.

I repeated the test about 5 times with an oscilloscope. It was more to test how my input power responds being switched by a relay, but I tested with and without a surge protector also to see how it behaved with the switches.

I found the relay to behave similar to what I would expect during load shedding.

 

[Rickster]

During loadshedding i switch off our main from outside, then wait 30 min after loadshedding has stopped then put it back on.

 

[maumau]

During loadshedding i switch off our main from outside, then wait 30 min after loadshedding has stopped then put it back on.

Started doing this too IF i'm home.

 

[bekdik]

I switch off earth leakage on db and leave a roof light on in order to see when power is restored.