mel wood Posted January 29, 2009 Share Posted January 29, 2009 Is it possible to use an adaptor when reverse polarity is a problem? How do I make one? Link to comment Share on other sites More sharing options...
Tony Jones Posted January 29, 2009 Share Posted January 29, 2009 Welcome to the family Mel. It's fairly straightforward. If you can change a plug, you can make one of these. You need (from your caravan shop) one of each "male and female" blue caravan plugs, and a short piece of 3-core flex, rated high enough for your requirements (or more!). Connect the flex to one plug exactly as per the markings inside, but connect the other plug with the Live (brown) and Neutral (blue) wires "wrong way round." Make sure you label it clearly "Reversed Polarity" or similar (indelible marker, or a label firmly fixed to the assembly). I assume you've already got something to test the polarity of any mains supply - if it shows up "wrong," you simply connect your new adaptor in line. Personally, I put my "reverser" into the site supply first, then my mains lead to the van, but I don't think the order matters too much. What is important is that your reverser only has a short flex, as you don't want the connectors lying on (potentially) damp ground. Tony Link to comment Share on other sites More sharing options...
mel wood Posted January 29, 2009 Author Share Posted January 29, 2009 Thank you. That answers the question perfectly. Link to comment Share on other sites More sharing options...
davenewellhome Posted January 29, 2009 Share Posted January 29, 2009 Alternatively you could fit (or have fitted) a reverse polarity switch. This device will warn you with an audible alarm if a reverse polarity, or worse, a no earth situation is present and allow you to correct the reverse polarity by just flicking a switch. D. Link to comment Share on other sites More sharing options...
George Collings Posted January 29, 2009 Share Posted January 29, 2009 An auto polarity switcher is very convenient but I still prefer to plug in my test at the post as it shows other potential faults such as 'no earth'. I lack in depth knowledge of 'mains' so if anything other than reversed polarity is revealed try other point /posts and do not hook up unless I find a safe one. It has only happened a couple of times in around 700 nights on sites in Europe Link to comment Share on other sites More sharing options...
davenewellhome Posted January 29, 2009 Share Posted January 29, 2009 The polarity switch is not an automatic device, it gives an audible warning as well as lighting an LED to give notice of a fault. It will warn of reversed polarity and no earth situations. In a simple reversed polarity situation the red LED lights and the buzzer sounds, simply flick the switch to correct it. If there is no earth present then both red and green LEDs light up and the buzzer sounds, flicking the switch will have no effect as the fault is no earth present. The best method of operation is to press the trip test button just before breaking camp. That way when you next hook up the power goes no further than the trip switch which is off unitl you have corrected any fault condition. D. Link to comment Share on other sites More sharing options...
George Collings Posted January 29, 2009 Share Posted January 29, 2009 Thank you Dave, In that case it a very nice bit of kit. Now, where did I leave my wallet wrench. Link to comment Share on other sites More sharing options...
davenewellhome Posted January 29, 2009 Share Posted January 29, 2009 Not that expensive at just £35 for DIY fit and typically £70 fitted. D. Link to comment Share on other sites More sharing options...
Ned Swift Posted January 29, 2009 Share Posted January 29, 2009 Apologies for asking an obviously silly question. I haven't been overseas yet but I have a two pin euro / 3 pin van adapter ready though. If on testing the polarity with a plug in tester, and it is found to be reversed - why can't you just turn the two pin plug upside down and plug it in the other way round??? (?) This would mean that the pins were now in the right holes??? Sure I've Missed Something Ned (^) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted January 30, 2009 Share Posted January 30, 2009 Dave may well be able to supply the Reverse Polarity Switch directly, but, if not, these are a couple of other sources: http://www.campervanaccessories.co.uk/mains-polarity-changeover-switch-caravan-motorhome-p-358.html?osCsid=c79a4e8a01600ac2f4ab9c8965f49093 http://caravanownerscatalogue.com/product_info.php?products_id=28&osCsid=342e4a4183d28da1bed93fccb2f4c11a ...................................................................................................................... Ned: If you encounter a mains hook-up point with sockets that exactly match your 'euro' plug (often referred to a "Schuko" plug) then you should be able to turn the plug through 180° to correct reverse polarity as the plug's earth contact is on the plug's outside edge. However, if the hook-up point has socket-connections that don't match your plug (and I suspect this is the norm rather than the exception), then either your Schuko plug won't fit or you won't be able to rotate it. Link to comment Share on other sites More sharing options...
Syd Posted January 30, 2009 Share Posted January 30, 2009 You should also note that some of these euro plugs have a thin bright strip of metal running down their outsides centred between the two pins and this is an earth strip so if you rotate them the earth strip will not connect. Link to comment Share on other sites More sharing options...
spospe Posted January 30, 2009 Share Posted January 30, 2009 Syd and Ned On my plug the 'thin bright strip' of the earth connector is on both sides and so it does make connection when plugged in upside down. It was bought in the UK and so I suggest searching round in order to find one if you don't fancy the idea of making up a reversed lead. It should be remembered though that it will be impossible on some continental bollards to reverse the plug due to space limitations. Link to comment Share on other sites More sharing options...
dikyenfo Posted January 30, 2009 Share Posted January 30, 2009 Just buy cheaper electrics from Spain or France which will be fitted with proper switches and stop pratting about. Also if the TV is bothering you use satellite with scart and any difference will be byepassed and work perfectly. Link to comment Share on other sites More sharing options...
Tony Jones Posted January 30, 2009 Share Posted January 30, 2009 More and more Continental sites (and Aires) are changing over to the "universal" blue plug. That's becoming the European standard, so for once we're ahead of the Euro-game. For the ones which haven't changed over yet, I carry another adaptor, with a blue "female" at one end and a French 2-pin-plus-earth at the other. The blue plug can only be used one way, so Mel either needs to "reversing adaptor" I described, or Dave's built-in system. (PS to Alec: I don't have any mains appliances on board, as we often do without a hookup. When we do plug in, it's to run the fridge and battery charger, and I'm not in the market for replacing either of those just yet!) Link to comment Share on other sites More sharing options...
Brian Kirby Posted January 30, 2009 Share Posted January 30, 2009 spospe - 2009-01-30 11:49 AM Syd and Ned On my plug the 'thin bright strip' of the earth connector is on both sides and so it does make connection when plugged in upside down. It was bought in the UK and so I suggest searching round in order to find one if you don't fancy the idea of making up a reversed lead. It should be remembered though that it will be impossible on some continental bollards to reverse the plug due to space limitations. It is also the case that some two pin adaptor plugs route the cable vertically downwards. Rotating these to correct polarity would be unwise, as the cable would be pulled into a tight 180o bend on exit, with potential strain on the plug connections and local fatigue on the cable.I like simplicity. Two pin adaptor, or CEE blue plug at bollard, and polarity reversal cable, as Tony describes, at the van if necessary. I also agree that the more important safety test is for an earth, which such devices as the W4 test plug also checks. Link to comment Share on other sites More sharing options...
dikyenfo Posted January 30, 2009 Share Posted January 30, 2009 Alternaterning current will never harm devices designed to run on it but the difference is with portable electric devices of British manufacture which do not have proper double pole switches but cheapo single pole and to make it safe to use these every house and caravan etc has to have the live applied to one side so the crap switch will isolate the device but in the rest of europe they still do things the proper way. Both 'sides' of mains wiring can be looked at as live merely alternating so double pole switches switch both sides off simultaneously. QED Link to comment Share on other sites More sharing options...
Philman Posted January 30, 2009 Share Posted January 30, 2009 Lots of French sites do not use the German Schuko 2 pin plug/socket. The French one is slightly different as it has an earthpin at the socket end and an earth hole at the plug end. Although the Schuko type will plug in to this type you would not have an earth connection. Phil. Link to comment Share on other sites More sharing options...
spospe Posted January 31, 2009 Share Posted January 31, 2009 The main reason for having single pole switches for mains electricity seems to be one of economics. As a domestic light switch only switches one pole, then only one wire (the 'live') has to be run to it. This represents a real saving in the cost of wiring a building and given that the switch isolates the live, then there is no reason to have a double pole switch to isolate the neutral as well. In fact a double pole switch, would in these circumstances simply be a waste of money. Single pole switches are fine for most domestic uses within the UK enviroment, the problem comes when we go abroad to countries which switch both poles, as then it becomes important as to which wire is the live and which is the neutral. The term 'reversed polarity' is misleading when applied to an AC circuit, as there is no reversal of polarity at all. We should use an expression such as 'reversed conductors', or maybe 'LN reversal' (live-neutral reversal) as this expresses the situation better. I hope that this clarifies things a little more ............ Michael Link to comment Share on other sites More sharing options...
Brian Kirby Posted January 31, 2009 Share Posted January 31, 2009 dikyenfo - 2009-01-30 12:53 PM Alternaterning current will never harm devices designed to run on it but the difference is with portable electric devices of British manufacture which do not have proper double pole switches but cheapo single pole and to make it safe to use these every house and caravan etc has to have the live applied to one side so the crap switch will isolate the device but in the rest of europe they still do things the proper way. Both 'sides' of mains wiring can be looked at as live merely alternating so double pole switches switch both sides off simultaneously. QED Pre the introduction of Residual Current Devices (RCDs) {or the earlier Earth Leakage Circuit Breakers [ELCBs]} as main switches on consumer boards, there was a greater risk of electrocution if polarity is reversed, than there is if these devices are present. Under most circumstances, provided there is an adequate earth, these devices have, to all intents and purposes, eliminated that risk. Under most circumstances, RCDs will cut the supply even in the absence of an earth, whereas ELCBs generally will not. If you have an ELCB, and you plan travelling abroad, it would be wise to get it changed for an RCD. If you are unsure what you have, ask an electrician.The remaining risk, in many UK wired vans, is the installation of fuses, or Miniature Circuit Breakers (MCBs), only in the "live" side of the supply. This arrangement does not adequately protect the circuit wiring from overload where polarity is reversed. Most continental installations seem to have twin breakers, switching both live and neutral, so that an overload will cut, and so protect, the circuit, whichever way the polarity is arranged.The most important safety measure is a good earth, without which all risks are magnified. Link to comment Share on other sites More sharing options...
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