Tiny Tim Posted June 17, 2011 Share Posted June 17, 2011 Help! Being relatively new to the world of touring in France and in the process of planning our first trip I have concerns over the question of reverse polarity which I understand can happen in French sites. Recently I was talking to a friend who lives in France and he was not aware of there being any adverse effect due to this and yet various guidance books including MMM's own and one published by France Magazine say that you should check polarity and in the event of a reversed system, you may need to use a connector rewired to take care of it. What danger, if any does this pose? Are we talking about damage to equipment or is it as bad as a potential fire risk? If anybody has any experience of this problem I would be grateful for their views. Tim Link to comment Share on other sites More sharing options...
T8LEY Posted June 18, 2011 Share Posted June 18, 2011 Hi TT One of the safety issues with reversed polarity of an EHU is any appliances connected to the mains socket outlets in your van will always be live, even if you think you have disconnected them from the supply by switching , because in the UK we commonly use single pole (SP) switches, ie switches in the line (live) wire, and on the continent they employ double pole (DP) switches in both the line and neutral. With a British made van you will probably have SP switches on your 230V socket outlets. If you don't have switched socket outlets, and you rely on an appliance switch to isolate something, just be aware, that also could be SP. Unplug the item for complete safety. Fixed appliances are another problem. The main switch on your 230V distribution board may be SP and if you had the need to isolate the supply by means of said switch (to work on a fixed appliance for example) the mains installation in your van would still be live. Should the need arise unplug the EHU. I'm not sure if reversed polarity would have any detrimental effect on battery charging these days. When chargers comprised a simple transformer, before electronic gubbins, polarity was not an issue. Link to comment Share on other sites More sharing options...
602 Posted June 18, 2011 Share Posted June 18, 2011 Hi, Agreed. In UK we switch off the live lead. If you have reversed polarity the switch will disconnect YOUR neutral, thus leaving the appliance "live". This shouldn't be a problem, provided there is not a fault in the appliance. As soon as you connect to the site mains, ask you wife to get you a beer out of the fridge. :D As mains supply is AC, current changes direction about 50 times a second, so you appliances will not be bothered by reversed polarity ........ not like the 12 volt DC radio in your car. 602 Link to comment Share on other sites More sharing options...
602 Posted June 18, 2011 Share Posted June 18, 2011 PS, You can buy a polarity/fault tester from you electrical supplier, TLC, Screwfix, Ebay, etc. It looks like a 3-pin plug with neon bulbs. Not expensive. My neighbours house was wired reverse polarity ..... self-built by a Canadian. Another neighbour has just dicovered that his recently purchased house does not have a single earth (By single, I mean nary a one). 8-) 602 Link to comment Share on other sites More sharing options...
Blizzard Posted June 18, 2011 Share Posted June 18, 2011 Hello Tim, When we started touring France, we bought a 'plug in' test plug, that illuminates to show normal polarity, reversed polarity and earth faults. We also carry a short length of orange 240v cable with the blue plug wired in reverse as well as one with the two pin continental plug. The adaptors have never been used in the five years we've had them as every site we have used so far uses the same set up as the UK, Ken. Link to comment Share on other sites More sharing options...
kelly58 Posted June 18, 2011 Share Posted June 18, 2011 On a recent trip to France one of the aires we stopped at had only one continental 2 pin socket and believe it or not there were 7 motorhomes running off it using a variety of adaptors when I did a test on the socket it showed no earth connection so I gave it a wide bearth. Link to comment Share on other sites More sharing options...
laimeduck Posted June 18, 2011 Share Posted June 18, 2011 Tim Hi I was in France last week & had reversed polarity on our final site at Liques near Calais. I used the tester & reverser kit, & had the peace of mind that all was OK. Details for tester & kit as below Polarity Tester & reverser kit available on line from "Jegs 11" on Ebay for £9.99 + post http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=350456367134&ssPageName=STRK:MEWNX:IT includes good instructions & he has all the Europe plugs you will ever need! Jeremy the L'AimeDuck Link to comment Share on other sites More sharing options...
lennyhb Posted June 18, 2011 Share Posted June 18, 2011 I never worry about it as our van is pretty much reversal proof as such. It has an RCD (which yours should have), a double pole MCB and un-switched mains sockets. Also we very seldom use hook-ups last year 56 nights away used hook-ups for 3 nights. If you have single pole switched mains sockets you can change them for un-switched or double pole switched sockets, Contactum, MEM Delta, Volex & a couple of other manufacturers sockets are double pole switched. You are pretty safe anyway the site hook-up has an RCD your van should have an RCD & most equipment you are lightly to use is in a plastic casing. It's a lot more dangerous to drive the van to your camping spot, better stay at home then. Link to comment Share on other sites More sharing options...
Tiny Tim Posted June 18, 2011 Author Share Posted June 18, 2011 Many thanks to all insomniacs and early risers for your input. When you get it explained it all starts to make sense. Following some of the responses, I am certainly going to get a polarity tester and a reverse wired connector to keep in the van. Thanks again. Tim Link to comment Share on other sites More sharing options...
BGD Posted June 18, 2011 Share Posted June 18, 2011 Never had any problems with "reversed polarity" living in Spain, and using EHU's often when touring around Spain and Portugal....both of which countries use the two-pin 220volt mains plugs which you can insert either way into any socket. Every time anyone hooks up to a two-pin socket, they are getting reversed polarity 50 times every second.....because that's what AC current does. I suspect that what some people aren't grasping is the fact that mains electricity is "AC", that is Alternating Current. In all European countries the current oscillates at 50 hertz, ie it changes direction 50 times every second..........so every second the left hand hand pin of your plug socket is live, then neutral then live then neutral, 50 times per second, and the same for the right hand pin..... a sort of "push-me-pull-you". If you like, it is reversing its polarity 50 times every second. (Yes I know that's not the full physics answer, but it gives people a picture of what goes on.) So it is NOT like the 12 volt DC system in your van, where "positive" is always positive and "negative" is always negative. All mains electrical appliances work regardless of which side of the cable starts the push-me-pull-you 50-times-per-second electrical effect. And all vans now have RCD circuit breakers for the mains supply anyway. The only precaution needed is to disconnect your EHU lead before doing any work on any mains equipment inside your van.......but that's blatant common sense whether in the UK or rest of world anyway. (For Europeans, with European spec electrical appliances, things DO get complex in the USA though, where the current is much lower, AND the hertz rate is different....from memory 120 and 55?) In edit: ooops........it's 60hertz in the USA. Link to comment Share on other sites More sharing options...
rupert123 Posted June 18, 2011 Share Posted June 18, 2011 Tiny Tim - 2011-06-18 9:17 AM Many thanks to all insomniacs and early risers for your input. When you get it explained it all starts to make sense. Following some of the responses, I am certainly going to get a polarity tester and a reverse wired connector to keep in the van. Thanks again. Tim Tim forget it, just more junk to carry around. Their is no danger at all from reverse polarity on a modern van. None on older ones either if you unplug from the mains before taking electrical stuff apart. Link to comment Share on other sites More sharing options...
Brambles Posted June 18, 2011 Share Posted June 18, 2011 What would be useful take is an adapter lead for european two pin + earth sockets as some sites may not have the round blue IEC sockets for hook up. Readily available from most caravan accessory shops or online. Link to comment Share on other sites More sharing options...
Tiny Tim Posted June 18, 2011 Author Share Posted June 18, 2011 Thanks Rupert and Brambles, points noted - all useful stuff. I agree that you dont want to carry more than you actually need. Tim Link to comment Share on other sites More sharing options...
sooty10 Posted June 18, 2011 Share Posted June 18, 2011 On a recent trip to Spain we were on an aire for a few days. Set the van up, tested the polarity and it was wrong. I then turned the plug round and yes it was ok, however next morning it had changed again and we found out that the polarity was changing a few times a day. When I asked round others found the same. Anyone any ideas. Sooty Link to comment Share on other sites More sharing options...
on the road again Posted June 18, 2011 Share Posted June 18, 2011 Also, never overlook the obvious, as I did recently when I found three sites in a row in France seemed to have reverse polarity (although it is pretty common over there and more so in Spain). Taking my newly purchased mains lead apart I found it had been wired in reverse by the manufacturer...... Chris Link to comment Share on other sites More sharing options...
lennyhb Posted June 18, 2011 Share Posted June 18, 2011 sooty10 - 2011-06-18 12:47 PM On a recent trip to Spain we were on an aire for a few days. Set the van up, tested the polarity and it was wrong. I then turned the plug round and yes it was ok, however next morning it had changed again and we found out that the polarity was changing a few times a day. When I asked round others found the same. Anyone any ideas. Sooty Possibly a 2 phase supply have come across these in France many years ago, when they changed from 110v in some of the more remote areas they used 2 single phases of 110v to achieve 220v it means you have 2 110v live feeds & neutral/earth. Link to comment Share on other sites More sharing options...
BGD Posted June 18, 2011 Share Posted June 18, 2011 sooty10 - 2011-06-18 12:47 PM On a recent trip to Spain we were on an aire for a few days. Set the van up, tested the polarity and it was wrong. I then turned the plug round and yes it was ok, however next morning it had changed again and we found out that the polarity was changing a few times a day. When I asked round others found the same. Anyone any ideas. Sooty Sooty - I'm intrigued.........why do you bother to test the polarity of any AC mains circuit? Link to comment Share on other sites More sharing options...
nowtelse2do Posted June 18, 2011 Share Posted June 18, 2011 Don't know who said it, but it was someone on here the last time this was brought up, still gives me a chuckle. If you have reverse polarity then all you do is turn the van around :-D Dave Link to comment Share on other sites More sharing options...
tonyishuk Posted June 18, 2011 Share Posted June 18, 2011 Our experience in France has taught us that the same electric box with multiple out lets can have normal, reverse polarity and no earth connections 8-) We carry a short length of cable made up of a blue plug and socket with the neutral and live wires reversed. If the tester shows reverse polarity, the lead is connected and back to normal polarity. Have had to use the cable on UK sites some times as well. Rgds Link to comment Share on other sites More sharing options...
Guest pelmetman Posted June 18, 2011 Share Posted June 18, 2011 Don't have a tester :D ...............still alive 8-) .................it's amazing :D Link to comment Share on other sites More sharing options...
T8LEY Posted June 19, 2011 Share Posted June 19, 2011 Hi again TT, Just a few points on other's comments: 1. Make sure your RCD, at the mains, is rated 30mA or less if you are going to rely on it for life protection. The rating is usually on the front of the device. 2. You will probably have a DP main switch, on your distribution board, but not necessarily DP mcbs (miniature circuit breakers). Again the label on the device should tell you. If they are single pole I think you know the problem by now. 3. You can change your socket outlets to DP but its much more difficult to do anything about fixed appliances. 4. The fact that the mains supply is a.c. is irrelevant to safety. The line voltage is always above earth potential and the neutral at or about the value of earth. In the UK we bond the neutral of the supply to earth at the supply point (secondary transformer) and at the load (domestic cut-out). You couldn't do that if the potential of the neutral was above the value of earth's. 5. Don't forget that isolation of equipment is not only necessary for maintenance purposes, you may want to switch something off for peace of mind to ensure your van doesn't melt whilst you're away, or even asleep. I would suggest, especially if you are not aware of the issues around reversed supply polarity, that you prepare a lead to cope with the problem, should it arise. Don't be lulled into a false sense of security about electrical installations. Just because you can't see anything is wrong doesn't mean there isn't. That's why isolation and automatic disconnection of supply are important issues in the IEE regulations. I bet that's sent everybody that's left off to bed! Link to comment Share on other sites More sharing options...
kelly58 Posted June 19, 2011 Share Posted June 19, 2011 pelmetman - 2011-06-18 8:32 PM Don't have a tester :D ...............still alive 8-) .................it's amazing :D Get one there is only one type of death ( permanent ) Link to comment Share on other sites More sharing options...
Tiny Tim Posted June 19, 2011 Author Share Posted June 19, 2011 Thanks again all for your responses - of both factions! Tim Link to comment Share on other sites More sharing options...
Wilf Posted June 19, 2011 Share Posted June 19, 2011 I do use a reverse polarity tester as a matter of course when over the water because it shows you what’s what at the hookup. The type that lights to show No Earth, Live & Neutral reversed, No Neutral, Live & Earth reversed etc Yes I have seen Live & Earth reversed and I made a fuss about that, but I don’t bother about reverse polarity. I own a Continental van that has two RCD type trips; so perhaps another question for the ones in the know. Are Continental made vans wired up differently from British made vans? Link to comment Share on other sites More sharing options...
lennyhb Posted June 19, 2011 Share Posted June 19, 2011 Wilf - 2011-06-19 5:47 PM Are Continental made vans wired up differently from British made vans? Continental vans normally have double pole MCB's but do not always have an RCD, & un-switched socket outlets. My Hymer did not have an RCD & a previous Hobby caravan I brought in Germany did not have a RCD but I know Brian's Hobby Motorhome did come with an RCD. If a Continental van is imported by a distributor they will fit an RCD if needed, it's only van brought direct from the Continent that may not have an RCD. British vans always have an RCD but usually have single pole MCB's and often single pole switched socket outlets. Link to comment Share on other sites More sharing options...
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