Polarity

Family ashnic
Family ashnic Forum Participant Posts: 2

Hiya. We will soon be heading to Europe for an adventure with our van. I have read loads of posts on here which have been brilliant for advice. I have read about polarity and purchased a tester but I'm not sure what to do if it's not ok. Does it mean no
electric while we are on that pitch?

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Comments

  • SteveL
    SteveL Club Member Posts: 12,303 ✭✭✭
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    edited July 2016 #2

    Some reckon it does not matter, but we carry an adaptor cable which you can make up yourself, or buy from a caravan shop, that switches it back. It is just a short length of cable with a male and female plug at either end, which reverses live and neutral. You plug this into the site post first and then your 25m lead into it. In France you may also require a continental adaptor, although most sites now have the modern European standard plug. These are also  available from a caravan shop.

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited July 2016 #3

    Depends on your caravans electric. Try another sockert first. Just don't stick a knife in your toaster to retrieve your toast while its plugged in. 

  • DSB
    DSB Club Member Posts: 5,667 ✭✭✭
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    edited July 2016 #4

    We have a plug in device which we keep permanently plugged into out kitchen socket - immediately visable when we open the caravan door.  If it shows we have reversed polarity we add our reversed polarity lead.  

    This is a very small lead that the have made up ourselves (male plug on one end, female on the other), where the live and nuteral wires are reversed on one of the plugs.  Attach this small lead either the caravan end or the electric bollard end, and that should solve the problem.

    Also remember to take with you an adaptor with an 'english' to continental adapter.  You can buy a made up lead for this at a caravan stockist.  We wouldn't be without ours although there days we feel there are more continental sites we have visited with our 'standard English' connection.  Whenever we go to Europe we always take a spare 'continental adapter'.  Most years we have to lend our spare to someone! 

    David 

     

  • Unknown
    Unknown Forum Participant
    edited July 2016 #5
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  • Metheven
    Metheven Club Member Posts: 3,987 ✭✭✭
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    edited July 2016 #6

    Or if you have a lead on a drum like I have, just reverse the L&N of one outlet and mark as such. I use one or the other depending on what the tester indicates.

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited July 2016 #7

    Depends on your caravans electric. Try another sockert first. Just don't stick a knife in your toaster to retrieve your toast while its plugged in. 

    :Eeek: It's not safe to do that whatever the polarity

    ... I never said it was... that's why I said not to while it was plugged in :-)

  • Unknown
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    edited July 2016 #8
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  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited July 2016 #9

    Agreed Dorset D. My last caravan, a 2002 Lunar had reversed polarity tell tale on the power supply unit ..... I've not found on on my 2013 Coachman .... but we've only had it a couple of weeks. 

  • paul56
    paul56 Forum Participant Posts: 937
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    edited July 2016 #10

    In reality, and I hope others will agree, problems with electricity in Europe are not that common.  I don't test for polarity as I don't think is matters that much, but others may.  However, I would never play with the electrics whilst plugged in regardless.
     The only problem I have found in the last few years was low voltage.  Modern fridges seem to dislike it and it can result in damage.  

    Totally agree DD. We've been touring the continent for the proverbial donkeys years and never tested the electric polarity yet and not had a problem. If anything untoward was to happen I'd unplug from the mains. At home I don't clean out the blades of the
    lawnmower without unplugging it or clean out the bread from the toaster without unplugging it.

  • easyonthegas
    easyonthegas Forum Participant Posts: 53
    edited August 2016 #11

    The polarity issue, I suggest is for older vans that do not have the current dual polarity isolation in their RCB or consumer unit.

    If you are working on the electrcial circuits, switch them off first at the isolator

    If you are normal consumer, the issue is not relavent, especially as most wall sockets do not have a switch (as you often do at home). If you are concerned, then upplug them at night.

    So don't worry, enjoy your hols and carry less equipment!

  • Wildwood
    Wildwood Club Member Posts: 3,581 ✭✭✭✭
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    edited August 2016 #12

    We have used several continental sites and never had a problem with polarity but it pays to carry something ready to deal with it just in case.

  • squip
    squip Forum Participant Posts: 42
    edited August 2016 #13

    Another important function of the polarity tester is to test for an earth connexion.

    At a site in Holland I moved pitch because the first pitch I selected did not have an earth connexion. I reported it to the reception but just got a shrug of the shoulders.

    squip

  • DougS
    DougS Forum Participant Posts: 327
    edited August 2016 #14

    Another important function of the polarity tester is to test for an earth connexion.

    At a site in Holland I moved pitch because the first pitch I selected did not have an earth connexion. I reported it to the reception but just got a shrug of the shoulders.

    squip

    Agree, if it's a standard neon indicator it should be renamed Reverse Polarity and Earth Problem Indicator.

    Then it's up to you if you ignore it or not, the RCD (if fitted) will hopefully protect you but the lack of an Earth is IMHO something that should be taken seriously.

  • Fysherman
    Fysherman Forum Participant Posts: 1,570
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    edited August 2016 #15

    The polarity issue, I suggest is for older vans that do not have the current dual polarity isolation in their RCB or consumer unit.

     

    If you are normal consumer, the issue is not relavent,

    So don't worry, enjoy your hols and carry less equipment!

    Please do not blindly follow this advice.

    There are several threads on this forum where more information can be obtained. Some of the posters are fully qualified sparks.

    Then if you want to risk your family for the sake of a £5 tester and a homemade swapped polarity cable made in less than ten minutes then go ahead

  • Remus
    Remus Forum Participant Posts: 132
    edited August 2016 #16

    Power goes in to a socket via the live and out via the neutral.  The switch "breaks" the power at the live inlet, result an "empty" socket that is not live.  In reversed polarity power goes in via the neutral and out via the live but the switch still "breaks"
    the power on the live side which is now the outlet, result a "full" socket that is live.  As others have said, buy a polarity tester (they are cheap) and keep a short length of cable made up with live and neutral reversed.  Many people say there is no danger
    if unwittingly using a reversed polarity circuit - they may be right as I'm no expert.  But why take the chance when the problem is easily overcome?  On a few occasions we found French sites with polarity reversed so the problem definitely exists.

  • Oneputt
    Oneputt Club Member Posts: 9,144 ✭✭✭
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    edited August 2016 #17

    Just come back from Europe and used a tester. Of the 9 sites we stayed at only one had reverse polarity

  • Fysherman
    Fysherman Forum Participant Posts: 1,570
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    edited August 2016 #18

    It only takes one of course (coupled with a faulty appliance in the caravan) but I do think they are getting better these days as they update their electrics to internationally recognised standards.

    When I first started, most were wired with the polarity reversed, particularly on French municiples.

  • Unknown
    Unknown Forum Participant
    edited August 2016 #19
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  • hitchglitch
    hitchglitch Forum Participant Posts: 3,007
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    edited August 2016 #20

    On an alternating current, the "Neutral" is connected to the Earth at some point in the system and has zero volts, the "live" alternates between 240 Volts positive and negative. In the UK our systems and appliances are wired with the switch and the fuse
    in the "live" side so if the polarity is reversed the switch is on the neutral side and if you switch off the appliance is still actually live. This is only potentially dangerous if you choose to work on your system or appliance with it still plugged in.

    On the continent they do not generally need to differentiate between live and neutral because all their switches are "two pole"; in other words the switch breaks both live and neutral.

     

  • Mitsi Fendt
    Mitsi Fendt Forum Participant Posts: 484
    100 Comments
    edited August 2016 #21

    The polarity issue, I suggest is for older vans that do not have the current dual polarity isolation in their RCB or consumer unit.

     

    If you are normal consumer, the issue is not relavent,

    So don't worry, enjoy your hols and carry less equipment!

    Please do not blindly follow this advice.

    There are several threads on this forum where more information can be obtained. Some of the posters are fully qualified sparks.

    Then if you want to risk your family for the sake of a £5 tester and a homemade swapped polarity cable made in less than ten minutes then go ahead

    I agree with Fysherman

  • markflip
    markflip Forum Participant Posts: 177
    edited August 2016 #22

    To save buying, making and carrying a 'polarity swapper' you can always whip the plug off your EHU lead and swap the L & N wires if you can't find a correctly wired outlet, just remember to swap them back when you leave.  My caravanning on the continent
    is limited but all three sites I have used had correctly wired EHU (with the 'normal' 16A plug as well).

  • jennyc
    jennyc Forum Participant Posts: 957
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    edited August 2016 #23

    Power goes in to a socket via the live and out via the neutral.  The switch "breaks" the power at the live inlet, result an "empty" socket that is not live.  In reversed polarity power goes in via the neutral and out via the live but the switch still
    "breaks" the power on the live side which is now the outlet, result a "full" socket that is live.
     As others have said, buy a polarity tester (they are cheap) and keep a short length of cable made up with live and neutral reversed.  Many people say
    there is no danger if unwittingly using a reversed polarity circuit - they may be right as I'm no expert.  But why take the chance when the problem is easily overcome?  On a few occasions we found French sites with polarity reversed so the problem definitely
    exists.

    Please explain how that works on an AC (alternating current) system. 

    Write your comments here...

    It works because in the power station the generator has three live elements (phases) all of which rise and fall between +240 and-240 volts relative to a common centre tap which is neutral. Neutral is permanently connected to the physical Earth at the power
    and substations, which is why you can get an electric shock just by touching a single live wire. It matters not to your body which which half of the 50Hz cycle you connect with, it'll still hurt. In practice with 50 reversals (as the generator rotates)  you'll
    feel both. Touching neutral while standing on the ground at a substation where it is grounded won't hurt, but the neutral voltage rises on the distribution to your house/ caravan, despite a metal neutral feed because the ground has resistance. Out of interest,
    defining the direction of current flow was done before atomic theory identified that the electron flow was the reverse of what we thought. That doesn't change meter readings or measured polarity, it's just a fact of interest to scientists working at atomic
    levels. In summary - don't touch a live wire.

  • Astro76
    Astro76 Forum Participant Posts: 62
    edited September 2016 #24

    For the sake of about £10.  For an extension plug, socket and a piece of 16A cable.   Making a polarity reverser is a no brainer really.    I've got no plans on going to the continent, but decided today to make a polarity reverser just in case the wiring
    on a UK campsite is done wrong.    I'd rather have this tool and never need it hook up to a site and have problems, took me about 30 mins to make one up. 

  • MFBSH
    MFBSH Forum Participant Posts: 6
    edited October 2016 #25

    When you plug in a caravan you're putting a potentially injurious voltage into an environment which comes into contact with the elements, and there are therefore hazards present. You mitigate the risks by having a tester and keeping it to hand. 

    If the polarity is reversed does this adversely affect the functioning of the RCD, an essential safety system; how will it be if you stand on wet grass and touch a conducting part of the caravan's structure; how strong and healthy does a person have to be
    not to be injured by a shock; does any system contain semiconductors? Not sure about stuff like this? - buy the kit. On our first caravan trip across the channel this summer 2 out of the 5 sites we used had reversed polarity. Five minutes with a small screwdriver
    sorted it (but remember to change the wires back afterwards!).

  • young thomas
    young thomas Forum Participant Posts: 11,356
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    edited October 2016 #26

    "On our first caravan trip across the channel this summer 2 out of the 5 sites we used had reversed polarity. Five minutes with a small screwdriver sorted it (but remember to change the wires back afterwards!)."

    if you make up a short 'reverse polarity cable' with a male and female connectors (as described many times, no doubt) you will only need to spend the five minutes with the screw driver once, and no remembering to change it back afterwardsWink

  • Unknown
    Unknown Forum Participant
    edited October 2016 #27
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  • DianneT
    DianneT Forum Participant Posts: 521
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    edited October 2016 #28

    We too have the Tester Plug used every time we visit a site and Lead but don't find many sites we visit with reversed polarity.

    DianneT

     

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited October 2016 #29

     ..... On our first caravan trip across the channel this summer 2 out of the 5 sites we used had reversed polarity. Five minutes with a small screwdriver sorted it (but remember to change the wires back afterwards!).

    Is your caravan fuse box double pole isolation? The French don't care whether it's reversed or not as they have double pole circuit breakers

  • chasncath
    chasncath Forum Participant Posts: 1,659
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    edited October 2016 #30

    "If the polarity is reversed does this adversely affect the functioning of the RCD, an essential safety system; how will it be if you stand on wet grass and touch a conducting part of the caravan's structure?"

    Just make sure you have an earth connection: your RCD compares the 'live' and 'neutral' current, which should be equal, and trips when there's an inbalance due to any fault leaking current to the earthed chassis. In your house, the 'earth' connection is made via the neutral wire, and any metal sheath on the cable. It's earthed at regular points along its length. On campsites, a  different set of rules apply and each Electric Hook-Up point must have a local earth spike to which the user's earth wire must be connected via the socket.

    In several continental countries, housholders have to supply their own earth points, usually a metal rod in the cellar.

    If your mains tester says there's no earth then don't use the supply!

  • hitchglitch
    hitchglitch Forum Participant Posts: 3,007
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    edited October 2016 #31

    "If the polarity is reversed does this adversely affect the functioning of the RCD, an essential safety system; how will it be if you stand on wet grass and touch a conducting part of the caravan's structure?"

    Just make sure you have an earth connection: your RCD compares the 'live' and 'neutral' current, which should be equal, and trips when there's an inbalance due to any fault leaking current to the earthed chassis. In your house, the 'earth' connection is made via the neutral wire, and any metal sheath on the cable. It's earthed at regular points along its length. On campsites, a  different set of rules apply and each Electric Hook-Up point must have a local earth spike to which the user's earth wire must be connected via the socket.

    In several continental countries, housholders have to supply their own earth points, usually a metal rod in the cellar.

    If your mains tester says there's no earth then don't use the supply!

    Reverse polarity is still quite common on the continent, even on sites with quite new installations. We experienced it a couple of times this year. I just ignore it but for anybody uncomfortable with this then do as advised in this thread. It is rare to have no earth and that is potentially far more dangerous. I was not aware that a local earth spike was required at each EHU. I have never seen one but it is certainly important to get a good connection to earth and the tester socket will show this. In that situation it would certainly be sensible not to use the supply.

    Concerning households with an earth connection in the cellar, this is not relevant as it would probably be what's known as a PME installation (Protective Multiple Earthing). This is not allowed on a camp site, however, if you are paranoid there is nothing to sop you creating a better earth by anchoring the caravan chassis to an earth spike. Some people do it apparently.

    Just to make things even more complicated, you may get false tester readings in Spain due to the occasional use of phase to phase transformers where the neutral floats. Not necessarily dangerous but confusing!