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LSainsbury
27-04-2008, 09:43
OK me and her indoors are having a "discussion" on power breakers...

Today she wants to mow the lawn. We have an extension cable (made for use outside) which the mower will plug into. Where does the power break go?

On the end of the extension which plugs into the wall or into the extension socket where the mower will plug into?

She says the extension socket, I say into the wall socket as you are protecting the entire circuit.

Vlad_Dracul
27-04-2008, 09:45
It goes in the wall socket then the whole system is protected. Do you also have RCDs on your "fusebox"?

LSainsbury
27-04-2008, 09:46
It goes in the wall socket then the whole system is protected. Do you also have RCDs on your "fusebox"?

It's a new house so I would expect so if they are standard regulations these days! :tu:

Paul K
27-04-2008, 09:50
Def wall socket.

bopdude
27-04-2008, 10:08
Yep, deffo the wall socket, as you said, it then protects the lead :tu:

Halcyon
27-04-2008, 10:26
Wall socket.
If you have it on the other end and then mow through the cable, it will be unsafe.
I'm sure your house power will trip but it will still be unsafe.
Connect at the wall socket.

Jon T
27-04-2008, 10:55
another vote for wall socket from me.

Don't want to be left with a live extension lead that could have been causing the fault in the first place.

papa smurf
27-04-2008, 10:56
so when you gona tell here :D:D:D

Raistlin
27-04-2008, 11:00
Wall socket.

You're then protected more fully if you cut the cable for the extension lead.

LSainsbury
27-04-2008, 11:43
so when you gona tell here :D:D:D

Already broke the bad news to her... :D

1 - 0 to me today...

Matthew
27-04-2008, 11:46
At the socket on the wall and everything is protected then.

greencreeper
27-04-2008, 13:11
Me as a teenager, happily cutting my grandad's hedge when the hedge trimmers just stopped. Completely dead. Odd. Checked the plug - still firmly in. Consumer unit - no tripped switch. Hmmm. Changed the fuse in the plug - still nothing. Resigned myself to a new pair of hedge trimmers. Started to tidy away the cable when I found these bare wires - as if someone had caught the cable in a pair of hedge trimmers and not realised :erm: :dozey:

So - safety starts with the individual. I never touch hedge trimmers now.

Octal
27-04-2008, 13:21
If it's a new installation I think you'll find all socket outlets on a downstairs ring main is assumed they are likely to be able to feed portable equipment outside, therefore they will be protected by an RCD at the consumer unit.

tweetypie/8
27-04-2008, 22:28
OK me and her indoors are having a "discussion" on power breakers...

Today she wants to mow the lawn. We have an extension cable (made for use outside) which the mower will plug into. Where does the power break go?

On the end of the extension which plugs into the wall or into the extension socket where the mower will plug into?

She says the extension socket, I say into the wall socket as you are protecting the entire circuit.

wall socket it is m8.;)

homealone
27-04-2008, 23:17
I raised this point with an electrician doing some wiring in our kitchen, he said we were protected by the RCD switches in the consumer unit - that they were the primary circuit breakers, & thus plugging in 'extra' ones was not necessary, whether wall plate or garden ???

- that is assuming they are properly fitted & earth bonded, of course ;)

bopdude
28-04-2008, 00:45
I raised this point with an electrician doing some wiring in our kitchen, he said we were protected by the RCD switches in the consumer unit - that they were the primary circuit breakers, & thus plugging in 'extra' ones was not necessary, whether wall plate or garden ???

- that is assuming they are properly fitted & earth bonded, of course ;)


You can never be too safe, I have worked on R.C.D's that were faulty and wouldn't trip under fault, of any kind :(

Better safe than sorry :tu: And if in doubt, ask, get somebody suitable.

homealone
28-04-2008, 01:06
You can never be too safe, I have worked on R.C.D's that were faulty and wouldn't trip under fault, of any kind :(

Better safe than sorry :tu: And if in doubt, ask, get somebody suitable.

Absolutely, hence my caveat about 'properly installed' :)

bopdude
28-04-2008, 01:15
Absolutely, hence my caveat about 'properly installed' :)

Indeed, what some folks aren't aware of is the test button on an R.C.D. this, when pressed should trip the breaker telling the owner that it is fully functional, just because it's there doesn't mean it's working, TEST them people :)


Just like you would a fire / smoke alarm.

homealone
28-04-2008, 01:17
Indeed, what some folks aren't aware of is the tst button on an R.C.D. this, when pressed should trip the breaker telling the owner that it is fully functional, just because it's there doesn't mean it's working, TEST them people :)


Just like you would a fire / smoke alarm.

Good advice :tu:

SMHarman
28-04-2008, 16:28
Me as a teenager, happily cutting my grandad's hedge when the hedge trimmers just stopped. Completely dead. Odd. Checked the plug - still firmly in. Consumer unit - no tripped switch. Hmmm. Changed the fuse in the plug - still nothing. Resigned myself to a new pair of hedge trimmers. Started to tidy away the cable when I found these bare wires - as if someone had caught the cable in a pair of hedge trimmers and not realised :erm: :dozey:

So - safety starts with the individual. I never touch hedge trimmers now.These things are additional protection, not a failsafe. I cut through the hedgetrimmer cable once. Slice sufficiently clean and quick that it did not trip the the house RCD or the one on the wall socket. Be careful.

altis
28-04-2008, 18:23
Perhaps it is helpful to understand how these devices work.

Residual Current Devices or RCDs sense any difference between the currents in the live and neutral conductors. If things are working properly, all the current entering an appliance through the live conductor will return through the neutral. If something conducting, such as a human, provides another route from live to earth then these currents will not balance. Commonly, these devices look for a difference of more than 30mA. As little as 60mA across the chest can overwhelm the human body's muscle control and prevent the heart from operating properly. Above about 200mA, it will stop completely.

Note that RCDs cannot detect faults, such as fire, that do not involve another current path. You should also use a fuse or circuit breaker with a current rating lower than the cable as well.

More details:
http://en.wikipedia.org/wiki/Residual-current_device

SMHarman
28-04-2008, 19:05
Exactly, so when the cable was cut the power did not go elsewhere and subsequently there was no power through the cable - no differential.

MovedGoalPosts
28-04-2008, 20:06
It's worth remembering that RCDs, since they can only work by detecting a current differential, i.e. leak to earth, requires that current to flow. Thus they won't stop you getting a shock, if you touch a live cable. However they should respond sufficiently quickly that the shock won't be fatal.

That's where the test thing comes in, but how many of us do that with RCD's hidden in inaccessible cupboards. In a way, even with a RCD protected consumer unit (fuseboard) the plug in device is good belt and braces. As that plug in is usually accessed to connect your device, it's much more likely you'll press the test button too.