Reversed Live and Neutral

[Damocles]

Just came across some sockets with reversed live and neutral today. Anyone got any comments on how dangerous they consider this to really be?

 

[dingbat]

Yeah, it means your plugtop fuse will be in the neutral, so even if it melts there will be live parts in the appliance, which would otherwise have been disconnected.

 

[Damocles]

Thanks for replies Ding. Nice to see someone else with a multi-forum obseesion.

Yes, I understand the fuse is in the wrong cable, But how much does this really increase the risks involved?

(Bearing in mind that plug fuses are a uniquely british invention anyway)

And what other problems might we have?

 

[dingbat]

Well, as other posters (over there) have indicated, many socket-outlets are single pole and switch in the live only. So, two main problems:

1) A device apparently switched off and not operating may still be live because the switching is in the neutral only.

2) For the same reason a fuse may blow due to an overcurrent fault but it will disconnect the neutral, leaving the equipment live.

Of course you should always unplug before you do any work on portable equipment, but some people don't read instructions!

 

[Damocles]

Yes, safety is a multi-layered thing. I was thinking myself broadly on the lines of, 'OK, live parts inside, but they should be fairly safely hidden inside. Still got an earth to any metalwork'. But the electric heater/toaster strikes me as a distinct candidate where people might stuff things inside, like metal knives. Especially as it is a kitchen socket.

 

[Thermo]

blimey we put bread in our toaster, wouldnt want to come to your house for tea and muffins!

 

[Damocles]

You never poked about in the bottom of the toaster to get that stuck hot cross bun out? I have

 

[andy]

Yes, safety is a multi-layered thing. I was thinking myself broadly on the lines of, 'OK, live parts inside, but they should be fairly safely hidden inside. Still got an earth to any metalwork'. But the electric heater/toaster strikes me as a distinct candidate where people might stuff things inside, like metal knives. Especially as it is a kitchen socket.

knives in toaster?! i really shud check the wirin 2 make sure that the live is actually switch off before i put a knife in there again!

 

[Damocles]

It was ok 'cos it was an all metal knife so i knew it wouldn't catch fire.

 

[andy]

It was ok 'cos it was an all metal knife so i knew it wouldn't catch fire.

 

[mackeral]

Would the reversed L/N affect anything that had a small motor ?

 

[plugwash]

no

 

[plugwash]

reversable plug and socket types for your viewing pleasure

europlug: 2 pin fits most european sockets (it will fit a british socket if you open the shutters manually)


german Schuko socket (used accross much of europe)


Schuko plug


hybrid schuko/french plug


italian plug and socket

 

[andy]

for AC supplies, polarity is not as important compared to DC supplies. AC alternates therefor has no polarity. the polarity comes form 1 side (neutral) being grounded sp you get 230V phase to ground and 0V neutral to ground.

main problem with reversing live and neutral is you may only switch the neutral so the live is still live. but then other countries have this kinda setup and dont seem to have many problems

 

[Paul_C]

As already noted, other countries use reversible plugs and most appliances have no real safety issues about reversed connections.

The big safety concern when this is done on British BS1363 sockets is the plug fuse then being in the neutral. You could end up with a cord of 0.75 (or even 0.5 sq. mm) connected to an outlet with only a 30 or 32A OCPD to "protect" it.