Reverse polarity in Europe?

[Steve-N]

In simple terms, (which a lot of folk do not seem to be able to use, or comprehend), if the polarity is reversed, it means that the negative and positive supply is back to front, so that when an electrical unit is supposedly switched off, there is still a positive supply running to it, so that it is still live.

This, in itself is not a problem, unless, as some have already mentioned, you intend twiddling about in the gubbins within the item in question.

Many supply points on campsites, especially in rural areas of France, are quite liable to provide a reversed polarity, but in itself this is not a problem with many modern motorhomes.

Some modern vehicles are fitted with gubbins which indicates when reverse polarity is encountered

If, however, you are worried about this situation, then purchase a polarity checker, and construct a reverse polarity lead.

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Personally, I always check (force of habit from days of yore) and on the odd occasion where I have come across the lack of an earth, then as an electrical nincompoop, I run on gas and battery until I move on, or I change pitch if possible.

Maybe somebody who is more aware of the electrical black arts than I, can advise on this lack of earth situation.

 

[Bibbers]

We have come across it quite a few times in Europe which causes a red warning light to illuminate on our control panel.
Of the 6 stops on our way down to Austria 3 have been reverse polarity including this one.
As we have come across it so many times in the past we bought a lead off the internet. £14 or so and is a short lead with the correct plugs at either end obviously with the connections inside wired to correct the problem.

 

[Steve-N]

I made up a polarity reverse item. Reversed live/neutral is quite common in France, and irrespective of whether a 'modern' van can manage this, it is fundamentally wrong.
I always check using a polarity checker plug and correct it if it turns out to be reversed.
As some have mentioned, the Neutral is effectively the return path for a circuit and any protective devices (fuses, mcb's or an RCD) operate by disconnecting the live conductor NOT the neutral.
This is potentially unsafe and should not be ignored !!!

 

[Pausim]

If I thought polarity was a problem in my van I would change the breakers and equipment to make it safe for international use. It would also make it safe for use with an inverter. I would not be faffing about with polarity checkers and reverse wiring connections.

 

[Apacheman]

Our van system deals with it. There is an indicator to say it’s reversed. Generally only happens on 2 pin Euro sockets and if I notice it I just turn the adapter round at the electrical box.

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[Pausim]

As some have mentioned, the Neutral is effectively the return path for a circuit and any protective devices (fuses, mcb's or an RCD) operate by disconnecting the live conductor NOT the neutral.

MCBs and RCDs in motorhomes should disconnect live and neutral. My last 4 motorhomes have all had 2 pole safety devices which do exactly this.

 

[gus-lopez]

Interesting, I thought harmonisation meant they had raised their 220V and we had lowered our 240V. It seems from what you are saying that everyone just changed the labels.

no they allowed +10% & -6%. this gets all countries within the same amount

People change the sockets or remove them to decorate and reverse the connections.

this is why it should be illegal & only allowed by someone who knows what they are doing

There is no standardisation in the connections at the back of a mains socket.

you wouldn-t get an electrical certificate on a new house if there wasn"t

There is no standardisation in the connections at the back of a mains socket.

course there is .plainly marked & if you have someone who cant get that right it might be better for all if they electrocuted themselves.

 

[varaizian]

That's why I usually put it in 'inverted commas'. 'Reverse polarity' is the term used by some people to refer to the reversal of the phase and neutral conductor in a single-phase AC mains supply. But everyone knows what is meant by it.

Of course those that know better will point out that one of the conductors (neutral) is permanently fixed at about zero volts with respect to earth. The other conductor (phase, aka line or live) has a voltage that varies sinusoidally between about 340V positive and 340V negative 50 times per second with respect to earth. The current also varies sinusoidally (alternates) from positive to negative 50 times per second, which is why it is called Alternating Current (AC). The root mean square average of a 340V peak-to-peak sinusoidal waveform is about 240V, which is why a single phase mains supply in the UK is referred to as '240V AC'.

Oh god, this takes me back! I spent 2 years on my HNC 50 years ago analysing 3 phase ac wave curves with trigonometry; and that was a mechanical HNC! Funnily enough we have a 3 phase supply at our house and some 3 phase appliances now so it wasn't wasted time.

 

[WillH]

Never checked so don't know, hasn't been a problem yet in over 30 years. Ever seen a French or German motorhomes bothering?

 

[Cliff Bryant]

Doesn’t that just exactly describe EU rules.? Pointless.

You don't know much about electrical and electronic specification, do you? It defines a specification to which products needed to comply to be safe in all markets. Prior to harmonisation certain products had tapped transformers to allow them to comply with other markets, you can guess what might happen when Del Trotter shipped between markets. After harmonisation products needed to be designed to work in all markets within the specified parameters. The electrical European committees were always overseen by Brits so effectively we made those 'pointless' rules, except they are in no way pointless.

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[coopc]

I would be more worried about this kind of thing. France a couple of yrs ago

 

[autorouter]

As some have mentioned, the Neutral is effectively the return path for a circuit and any protective devices (fuses, mcb's or an RCD) operate by disconnecting the live conductor NOT the neutral.

This is simply not true. It is possible to get single pole RCDs if you look hard enough, but all the ones I've seen, even in UK consumer units, are double-pole, which means they switch both live and neutral.

UK MCBs are usually single-pole in domestic circuits. However in motorhomes you will find that UK manufacturers fit double-pole MCBs. DIY converters should do this too, but not all of them do, it's worth checking.

Of course a fuse in a fused 13A 3-pin UK plug is single-pole, intended to be in the live feed. If live and neutral are reversed then it is a potential hazard. European plugs are not fused, so that problem doesn't arise. That's why the Europeans don't have a problem with live/neutral reversed supplies, but UK motorhomes (with their fused plugs) do have a problem.

 

[ronboyracer]

I had no idea I was supposed to be afraid of my Truma boiler!! I haven’t been but I am now. Mind you I ended up being afraid of the Phantom tracker. Dan told us about shaking the device but he forgot to tell us you also have to arm it by pressing the button first so a phone

How often have you guys experienced reverse polarity on the continent? What’s the options for solving this issue is it as simple as making up a new lead with reverse polarity and a test lead with a martindale

call en route to the campsite. Then again after fuel. We said we’d shaken it. Were told the batteries were probably flat by Phantom,Nick read the instructions whilst I was driving and found the button and all good. Phew!!

Off to Vanbitz Monday for Strikeback Growler. Hadn’t expected them to be able to fit us in before our trip. Just hope the V5 arrives.

I seem to remember many year's ago, when motor homes were tethered electrically, for weeks on end, on any particular site, could cause a meltdown in the control box, that's when I got a polarity checker, and made up a reverse polarity lead, like already suggested, perhaps modern vans dont suffer from that now Regards Ronboy.

How often have you guys experienced reverse polarity on the continent? What’s the options for solving this issue is it as simple as making up a new lead with reverse polarity and a test lead with a martindale

 

[Old Gibber]

this is why it should be illegal & only allowed by someone who knows what they are doing

you wouldn-t get an electrical certificate on a new house if there wasn"t

course there is .plainly marked & if you have someone who cant get that right it might be better for all if they electrocuted themselves.

Couldn't agree more, yet people on here are advocating making up their own reverse polarity corrector leads! Also ready made ones are illegal in this country, so are not made to any specification and therefore may be less safe than simply doing nothing.

 

[Dolmen]

I wouldn’t know if we hooked up and it was, is it dangerous, I am maybe glad I never know

Never - not that have been aware. loads of threads on here about this. Do a search. A lot of disagreement on the subject too.

I’m with posts 2 and 3, seems to have summed the thread up before it even got going

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[Hettie's Crew]

We had this issue around 10 years ago in some rural parts of France when we had our 2011 Swift Bessacarr, it came up on the panel and I got quite adept at changing over the wires in the EHU lead. I also came across a site in the UK that had 3 pin sockets. When I got home I made up a 2 pin converter, a reverse polarity and 3 pin converter. Haven’t used any of them yet.

 

[autorouter]

Couldn't agree more, yet people on here are advocating making up their own reverse polarity corrector leads! Also ready made ones are illegal in this country, so are not made to any specification and therefore may be less safe than simply doing nothing.

So.. my socket tester says that live and neutral are reversed, but the earth is fine. I plug in my 'reverse polarity' corrector adapter lead. I then test with my socket tester, and it shows all correct. How is that less safe than simply doing nothing?

 

[DerekDethleff]

As mentioned above, France are suspects for reverse polarity and I used to check with a polarity tester when caravanning. The new Mho may have something to sort it out but stayed at Castel La Bien Assise near Calais this June and the polarity was reversed on the bollard. Not really problem unless you are fiddling with appliances, as stated above. However the Trauma water heater seems to be sensitive to 240v input and would not work and came up with a fault (sorry cannot remember which one) which manual said was the electrical supply. Heater worked fine at next campsite and on gas though. I have converted another lead - reversed the live and neutral and marked it so that I have a backup, but probably over the top.

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[Clive Mott]

Providing your van has an RCD and you dont dismantle mains stuff with the hookup connected and your hookup lead has good earth continuity then you have little to worry about. And when the toast gets stuck in the toaster UNPLUG THE TOASTER before you introduce a knife to get the slice out.

 

[Richard n Ann]

So.. my socket tester says that live and neutral are reversed, but the earth is fine. I plug in my 'reverse polarity' corrector adapter lead. I then test with my socket tester, and it shows all correct. How is that less safe than simply doing nothing?

Have you considered the risk of adding extra joints into the EHU lead? Extra risk of Water ingress and poor connections causing heat. Small risks but so are the risks of reverse polarity.

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[theboggys]

Reverse Polarity is a term usually used to describe where a 230V device, like a household appliance, e.g Toaster, has been wired incorrectly at the plug so that the Live/+ power travels down the Neutral/- wire of the 3 wire cable.

Normally the Live/+ voltage would pass down the Brown wire which is where most Appliances have the On/Off switch.
The Blue wire is used for Neutral and the Yellow/Green wire for Earth. (This is the colour code for the UK, other countries have different colours).
It is not an uncommon situation in the UK where somebody fits a 13A plug to, for example, a Kettle they have purchased and accidently reverses the wiring so that the 230v Live/+ comes in down the Blue neutral wire in the cable.
This is reversed Polarity.
Something like a Kettle will continue to function if connected this way. Unless a fault develops with the appliance.

However, even when the device works correctly there can be a 'perceived' safety issue as the On/Off switch is sometimes only located in the Brown/cable.
If the Polarity is reversed much of the cable in the device would still be 'live' when 'switched off'. If someone then opened the Case and put their fingers into the wiring, they might be injured.
Which is why 'standard practice' suggests removing the power supply plug from the wall socket before opening a 230v device and touching live wiring.

Much is made of this 'danger', yet it quite clearly isn't a safety risk as few sensible people are going to open up any 230v device while it is still connected to the wall 230v socket and put their fingers on the bare wires!!
Even less people are likely to do this in a Motorhome.
Fewer still are likely to be stupid enough to expose an Appliances wiring while still 'live', in a Motorhome at exactly the same time as the Bollard has been wired 'reverse Polarity'.
Even back in the 1980's the likely hood of that combination of 'disasters' happening all at the same time has got to be a million to one, yet some sources suggest it is more likely than getting a Green Bannana from Asda's fruit section.


While a Kettle, Toaster and many other devices may function and be perfectly safe with the Polarity/Wires reversed, some electronics will not.
Older technology Electronics/Electrics expect the +/Live current to be coming in on the Brown wire. Some older Electronic units (like Chargers) will fail to operate properly if the wiring has been mismatched with the Live/Neutral wiring been reversed.
This can stop some older technology chargers from working correctly.



To combat this issue of 13A plugs being incorrectly fitted in the Home, new UK regulations were introduced (around 1990?) that specified all Appliances being sold in the UK, had to be pre-fitted with a 13A plug so that purchasers are less likley to fit a 13A Plug with wires/Polarity reversed
Around the same time Appliances began to be 'Double Insulated' and 'double pole' switched, i.e. a switch in both the Live wire AND the Neutral wire.
UK quality Electronic devices (from say 1999 onwards) began including features to cope with Reverse Polarity by having
Double Pole switches and Polarity protected Electronics, following the mainland Europe practice started many years before.

So with 'Double Pole' switching and 'Double Insulated' adding even better protection, it makes our million to one example above, now a one trillion to one risk.
I therefore don't understand why it is even mentioned any more?


In France and Spain, they had long ago realised that even when good standards were in place, people did not always follow them in the home. So the majority of French and Spanish manufactured 230v Appliances of the 1970's and 1980's took account of Voltage Polarity reversal and generally worked/were safe on both.


Any Camping Site Electric Hook-Up (EHU) bollard should follow the European 230v wiring standards on all camp sites.
But in the 1980's some French and Spanish camp sites were slow to adopt the more rigidly enforced standards. It had never been a problem before, so some viewed it as unnecessary bureaucracy.
But with growing International travel it was soon discovered that the electrics/electronics in British Motorhomes and Caravans were not as tolerant as the French, German and Spanish items.
Up until about 2002, some British built chargers (TV's, etc) would explode if the polarity was reversed.

The situation is now very different. Double Insulated, Double Pole switched and Polarity Reversal proof appliances are the norm.
Chargers from Schaudt, Toptron, Nordelettronica, Reich, Arsilicii, CBE, etc will all function on either 230v polarity.
A modern, quality Motorhome like Burstner, Hymer, Dethleffs, N&B, Knaus, etc. will happily function on any Polarity and has for about 20 years.

Talk to a native of Germany, Spain, etc about 'Reverse Polarity' and they won't have a clue what you are talking about, because for many years everything in their countries has been built around it being a potential daily occurrence so not a safety issue.
However, some British built Motorhomes had a 'Polarity Detection/Reversal' device right up until about 5 years ago rather than focus on 'safety with ANY polarity'.


So while the issue in the 1980's with 'Reverse Polarity' was significant, it is now not the problem it was with a quality, modern Motorhome/Caravan.
Much of the advice you will read will be old and no longer so relevant.



However, if you are still concerned, focus on making your Motorhome Polarity resilient, just as the continental's do, rather than going around looking for EHU Bollards that are not wired the 'UK' way.




12v Reverse Polarity is where the Battery is connected the wrong way around, potentially more expensive than 230v Reverse Polarity.
Camper Van/Motorhome Technicians sometimes connect a 12v battery the wrong way around creating a 'Reverse 12v Polarity' situation, usually with lots of Sparks and Pops.

Not many electronic devices will escape that without damage so make sure the battery leads are clearly marked up with Red and Black Tape before you remove them.
Use Red tape to mark the Positive Lead, sometimes a Blue or Black wire, and mark the Negative cable, sometimes a Brown wire, with Black Tape.
And yes I have got that the correct way around, some Caravans/Motorhomes will have Blue or Black wires for the 12v Positive/ + feed and Brown for 12v Negative/ -.
Even though the same Motorhomes may then use Brown for 230v Live and Blue for 230v Neutral, the International standard for 230V, there is no International standard for Motorhome Habitation low voltage (12 or 24volt DC).


If you are not sure which is which on 12v circuits, most Battery terminal Clamps have a +/P or -/N sign cast on to them or onto the casing near the terminal.


German motorhomes generally have the following wiring Colour codes :


Habitation battery 12v
Positive : Black
Negative : Brown
The Cable running between the Power Control unit and the Starter battery is usually Red

230v Mains (as per the UK)
Live : Brown
Neutral: Blue
Earth : Yellow/Green

Engine compartment (Starter) Battery (as per the UK)
Positive : Red
Negative : Black





230v MAINS SAFETY.
Most Motorhomes (but not all) have a 'Test' button on the mains RCD, this should be tested on a regular basis, like so :
With the EHU connected and the switches in the Up/On position, Press the test button and the RCD should flick Down into the 'Off' position.
Your Home should also have a test button in the Mains input Fuse/RCD box which should be tested on a regularly basis to ensure it is protecting the Home.


Note the test is only relevant with Mains connected, as it uses the 230v supply to trip the switch Off/Down.
The RCD will not 'trip' down if there is not 230v power at the RCD unit.

This is a useful way of testing if there is 230v applied to the vehicle when issues arise. If you press the RCD test button when on EHU and it doesn't trip off, there is a 230v supply issue up to the RCD, usually outside the vehicle, possibly the EHU cable.

 

[Ian Bosman]

I seem to remember Dan only told us about "the button" at the last minute. Only forgotten to switch it off once so far! Can't remember anything mentioned about shaking the tracker.

UK management to electrcal circuits 240 volts does NOT switch the neutral line (Blue wire )only the live line (Brown wire) _ on a 13 amp three pun socket so in Europe you may find that the wiring with reversed polarity is that you are in fact switching the neutral which is why it is important that you carry a device to check you have the correct polarity into you van. It also acts as a device to indicate you actually have incoming mains, not all van have this indicated, my Elddis Autoquest 2015, does not have any indication so these indicator devices come in useful when the mains is not operating at the Campsite/Stellplatz/Aire post as happened to me a couple of weeks ago in Austria where I plugged into the indicated socket for the post I was on to find no mains on it. I use an adapter to switch the live/neutral at the end of my main s lead for the EHU. About a foot length of mains lead with a plug one end and socket the other to plug my EHU cable into. I carry two adapters one for the blue 16Amp and one for the two pin Schuco type as found in many German sites increasing less so these days. Saves a lot of hassle and ensures your safety. Remember that our UK sockets are claimed to be the safest in the world as they are shuttered and fused.
BTW you are recommended NOT to buy those devices which plug in to a 13 amp socket to blank it off, they defeat the object of the socket shutters so are dangerous

 

[autorouter]

So with 'Double Pole' switching and 'Double Insulated' adding even better protection, it makes our million to one example above, now a one trillion to one risk.
I therefore don't understand why it is even mentioned any more?

Er... I think you forgot about the fuse. Is the fuse that is in every single 13A 3-pin plug single-pole or double pole?

 

[The Wino]

Er... I think you forgot about the fuse. Is the fuse that is in every single 13A 3-pin plug single-pole or double pole?

In houses with modern electrical systems do we actually need the fuse anymore and how many people have the correct fuse for the appliance it's connected to

 

[autorouter]

If the Polarity is reversed much of the cable in the device would still be 'live' when 'switched off'. If someone then opened the Case and put their fingers into the wiring, they might be injured.

Are you saying that someone deliberately opening the case and putting their fingers into the wiring is the only possible hazard scenario?

What about that example I mentioned of a child falling over on a chair onto a hairdryer, breaking the plastic case? And any of the other potentially lethal hazard scenarios that occur when kids and old people are around?

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[autorouter]

In houses with modern electrical systems do we actually need the fuse anymore and how many people have the correct fuse for the appliance it's connected to

It's a long thread, I already answered that question in post #43

Because in a brand new, modern, certified UK domestic system you can plug the same device, with its 3-pin plug, into a UK ring main, which has a 32A trip. That's the reason all appliances in the UK have a fused plug, otherwise you would need 32A plugs and 4mm² wires on everything..

European electrics have radials with 16A trips, and all appliance plugs don't need fuses. They use 1.5mm² wire which is OK for 16A.

 

[AllesP]

How often have you guys experienced reverse polarity on the continent? What’s the options for solving this issue is it as simple as making up a new lead with reverse polarity and a test lead with a martindale

We simply ignore it. I've been led to believe that you only need to worry about it if you are working on the electrics. But everything works normally when we are on a site with reverse polarity, so I wouldn't worry.

 

[Lullabys and Laybys]

How often have you guys experienced reverse polarity on the continent? What’s the options for solving this issue is it as simple as making up a new lead with reverse polarity and a test lead with a martindale

Yes that’s exactly what I do. I have two continental extensions one rewired to the reverse polarity. And a tester that just plugs into my 3 pin uk socket

 

[Richard n Ann]

What about that example I mentioned of a child falling over on a chair onto a hairdryer, breaking the plastic case?

That must be a Wish hairdryer I think you'd need a van to run over a normal hairdryer to destroy the case sufficiently to expose the wires, even then what moron would try and pick it up? While plugged in!?

 

[autorouter]

Reverse Polarity is a term usually used to describe where a 230V device, like a household appliance, e.g Toaster, has been wired incorrectly at the plug so that the Live/+ power travels down the Neutral/- wire of the 3 wire cable.

On this forum, the 'Reverse Polarity' (ie live/neutral reversal) we are concerned with is where a campsite supply is wired incorrectly, so that the normally neutral pin is live, and the normally live pin is neutral.

This is fundamentally different to the situation you describe, ie a miswired appliance plug. That's because with a miswired appliance plug, the fuse still remains on the live feed, so if the fuse blows, it still isolates the live supply from the rest of the appliance. That explains why you do not take it into consideration in your subsequent discussion.

However when the supply to the whole vehicle is live/neutral reversed, all the appliance plugs have their fuses on the neutral side. So if a fuse blows, the whole of the appliance wiring remains live, all the way to the fuse which is now in the neutral wire.

Any fault or accident which blows a fuse, and also breaches the integrity of the appliance casing, will result in the broken mess of wiring remaining live. This possibility is something you do not mention.

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