Reverse polarity

[barry_374350985]

Hi all,

I,ve seen mention somewhere that in in France it's wise to have a reverse polarity tester because sometimes the EHU is set up in reverse. Is this problem common / does anyone have any experience of this ? ie Do I need to take a reverse polarity tester ?

Barry

 

[Coops]

Barry.

Yes, you can always expect a large proportion of the local type hook-ups (as opposed to the blue Euro ones that we use in the U.K.) to be reverse polarity. This occurs because whereas in the U.K. our switches only interrupt the positive side of the supply, the continentals switches are double pole and interrupt both positive and negative sides, therefore polarity is of no great importance to them. When the site has the blue Euro type connection, we have always found them to be correctly wired. Even so, the very first job after connecting is to use the polarity tester. If the local type hook-up is found to be reversed, it is usually possible (because it is usually a two pin plug) to merely put the plug in the other way round. There is no need to take any special polarity tester with you - that is what a normal polarity tester is for.

 

[ThePlotter]

I have found both types of socket reversed so check all of them and never ever turn the plug the other way up because then you have no earth.

All you need is to get yourself about 12 inches of mains lead and the male and female blue plugs then wire one correctly and the other with positive and negative reversed,then when you come across reversed polarity,plug this lead into the van and your normal mains lead into that and bingo now the correct polarity.

 

[Lutz]

The advice never to turn the plug round the other way only applies in case the earth connection is via a third pin sticking out of the socket. This applies mainly to France and southern Europe. Other countries often have two earth connections on the outside of the plug. Where this is the case, it is perfectly safe to just turn the plug the other way round.

 

[EvansofSprot]

The advice never to turn the plug round the other way only applies in case the earth connection is via a third pin sticking out of the socket. This applies mainly to France and southern Europe. Other countries often have two earth connections on the outside of the plug. Where this is the case, it is perfectly safe to just turn the plug the other way round.

Surprisingly I didn't know that even though its so logical - thanks.

 

[KeithJ]

Hi Barry. Yes you must get a polarity tester for use abroad. Just stick it in one of your 13 amp power outlets when connecting to the site mains. I never travel without one as about 50% of sites have reversed polarity, whatever type of sockets they use (international or continental). It also tells you if there is an Earth fault - this occurs a lot in Spain.

Make up a special lead to correct the polarity as the Plotter says.

Keith

 

[barry_374350985]

Barry.

Yes, you can always expect a large proportion of the local type hook-ups (as opposed to the blue Euro ones that we use in the U.K.) to be reverse polarity. This occurs because whereas in the U.K. our switches only interrupt the positive side of the supply, the continentals switches are double pole and interrupt both positive and negative sides, therefore polarity is of no great importance to them. When the site has the blue Euro type connection, we have always found them to be correctly wired. Even so, the very first job after connecting is to use the polarity tester. If the local type hook-up is found to be reversed, it is usually possible (because it is usually a two pin plug) to merely put the plug in the other way round. There is no need to take any special polarity tester with you - that is what a normal polarity tester is for.

Cheers Leslie,

So you try the polarity tester after you've hooked up ? Won't this cause harm if the polarity is wrong ?

Barry

 

[ThePlotter]

Lutz agree but the post specifically refered to France

 

[Michael_374349176]

I agree with all that has been said, a tester and a "corrector" is a necessity when using the electrical supply on the continent. I had an argument with the owner of a site in Rudesheim in Germany who intimated that we British were paranoid about the subject, however we have the safest supply and the most stringent regulations concerning electricity. How many hotels in England have hair dryers in the bathroom as is common in Europe? The live line in Britain has the switch which means the appliance is safe when switched off. If the nutral line has the switch the appliance remains live and therefore unsafe.

 

[Lutz]

I have never heard of electrical safety, or lack thereof, being an issue of any major importance over here on the Continent. If all components of an appliance with which one may come into contact are fully insulated then it is unimportant whether the inside workings of that appliance remain live or not. This is the reasoning behind the Continental approach to electrical safety. That is also why the majority of low power appliances aren't even earthed.

 

[giovanni_5060838]

Sorry micheal, but you are incorrect,concerning safety.

In the uk the breaker switch is on the live only,on the continent both the live and neutral have breakers. So which is actually the safer? If you think about it a continental caravan is safe both on the continent and here in the uk,because it has a double break, its only our uk build vans that can have this problem.

Its actually amazing that caravan companies in the uk do not fit sockets that have the break on both the live and neutral,which are available here and would be the perfect solution,i have fitted them to my van already.

Any van build from after 1994,in the uk should already have a double pole switched RCD,and a double MCBs so the level of protection is already vastly improved.like i said amazing that uk build vans do not have the double poled sockets,this would then eliminate the problem completely.

 

[Lutz]

If, in any given circuit, an appliance is on then obviously the neutral side is also conducting current. Therefore, the neutral side of any additional socket in that same circuit will also not be dead, either, or have I got something wrong? I presume that UK plugs are fused in order to provide protection in such a case but what if I use an appliance with a Continental plug and adapter in the UK, none of which are fused?

 

[rob_jax]

Hi Lutz,

No - UK plugs are fused to protect the appliance cable and the ring main.

UK houses are wired with a ring of cable for each floor and a single MCB for each ring - rather than the European style of multiple linear (spur) supplies each with an individual MCB.

The problem is that the UK ring will have the protection MCB rated much higher than the capability of the appliance wiring - so the individual plugs need a fuse to protect the appliance wiring.

There's also another "gotcha" in UK house wiring - the ring may be rated at 30 amps - but it's constructed by allowing current to flow both ways around the ring - and consequently the ring only needs to be built from (say) 1/2 rated wire. That's fine as long as part of the ring doesn't fail - and then you have a section of under specified wire trying to pass 30 amps - and then you need that fuse to protect the ring from an appliance fault or probably have a fire...

Robert

 

[Lutz]

Hi Lutz,

No - UK plugs are fused to protect the appliance cable and the ring main.

UK houses are wired with a ring of cable for each floor and a single MCB for each ring - rather than the European style of multiple linear (spur) supplies each with an individual MCB.

The problem is that the UK ring will have the protection MCB rated much higher than the capability of the appliance wiring - so the individual plugs need a fuse to protect the appliance wiring.

There's also another "gotcha" in UK house wiring - the ring may be rated at 30 amps - but it's constructed by allowing current to flow both ways around the ring - and consequently the ring only needs to be built from (say) 1/2 rated wire. That's fine as long as part of the ring doesn't fail - and then you have a section of under specified wire trying to pass 30 amps - and then you need that fuse to protect the ring from an appliance fault or probably have a fire...

Robert

I understand, but doesn't it mean that even with a UK style ring circuit, one could still get a nasty jolt if you touch a bare neutral lead so long as an appliance somewhere in that same ring is switched on?

 

[rob_jax]

I understand, but doesn't it mean that even with a UK style ring circuit, one could still get a nasty jolt if you touch a bare neutral lead so long as an appliance somewhere in that same ring is switched on?

Hi Lutz,

When I've measured the voltage on a neutral wire (compared to earth) I've seen around 50 volts AC present. And yes, you'd feel that if you touched the neutral wire and had expected it to be floating around 0 volts...

Robert