Reversed polarity

[Talbot Bertha]

Wouldnt know to be honest ***** my current van is an old express and has a zig charger and the 240v is on a normal distribution board, I'm picking up my new one on saturday an '05 Ducato with a mclouis conversion so i'll have a poke around a see what's on it. Besides a working heater comfy beds and the lack of a shower over the kitchen!

 

[Deleted member 9215]

hi there

i have a chausson van whitch is French, we are thinking of takeing it to france next summer and was going to get a suitcase genny to avoid the reverse polarity , but these give a fault to now im not sure what to do)

dunk

 

[Kontiki]

The Chausson being a French made van, made for the French to use on their electricity system If your worried get yourself a polarity tester & make up a short cable with the live & neutral wired the opposite way on either the pug or the socket. Personally I think in reality unless you have a problem with any of your electrics having reverse polarity doesn't make any difference. It is only the British who seem to have this obsession with the polarity to the Europeans they don't care as they build their vans to cope with the EU electricity supply. As I said a polarity tester will also check that you have an earth on the system which is probably more of a concern.

 

[Deleted member 9215]

The Chausson being a French made van, made for the French to use on their electricity system If your worried get yourself a polarity tester & make up a short cable with the live & neutral wired the opposite way on either the pug or the socket. Personally I think in reality unless you have a problem with any of your electrics having reverse polarity doesn't make any difference. It is only the British who seem to have this obsession with the polarity to the Europeans they don't care as they build their vans to cope with the EU electricity supply. As I said a polarity tester will also check that you have an earth on the system which is probably more of a concern.

hi there i never thought about it before i read about the problem with a genny.
i think this is the way i will go anyway incase i need it for when im wilding sometime

p,s thanks for the reply.

dunk

 

[Deleted member 3011]

Could I suggest that since mains electricity does involve potentially fatal outcomes if the RV system supply and protection fails or is incorrectly installed or modified, those giving advice to persons with unknown skills and experience might be taken more seriously if they state their relevant trade or professional qualifications and experience.

One assumes that since "polarity reversers" are considered essential equipment for UK RVs even when hooking up in the UK, there might be some deficiency in UK regulations governing installations within RVs and parks that either is not present in European RVs and parks, or perhaps has been rendered irrelevant by superior equipment installed in European-built RVs.

 

[John H]

Could I suggest that since mains electricity does involve potentially fatal outcomes if the RV system supply and protection fails or is incorrectly installed or modified, those giving advice to persons with unknown skills and experience might be taken more seriously if they state their relevant trade or professional qualifications and experience.

One assumes that since "polarity reversers" are considered essential equipment for UK RVs even when hooking up in the UK, there might be some deficiency in UK regulations governing installations within RVs and parks that either is not present in European RVs and parks, or perhaps has been rendered irrelevant by superior equipment installed in European-built RVs.

I don't know anything about electricity and this point is not about eletricity - it is about assumptions. Who is it that "assumes" polarity reversers are essential equipment and could it be that these people making the assumptions are the same people who make and sell polarity reversers? I don't know but I do know there are plenty of people who are willing to tell you anything to make a quick sale.
PS we don't have a polarity reverser and have never had a problem - even on some dodgy-looking campsites in eastern Europe. Maybe we are lucky or maybe the qualified electrician we met in Luxembourg on our first trip was right and they are unessential in any van built this century.

 

[Talbot Bertha]

John i'd have probobly needed one in Bertha as how she was wired reverse polarity could have been a problem if a fault developed, however i doubt one would be required in my new van or indeed any modern van. Now to finish off removing any bits i may need from the old one before i get the new one tomorrow .

 

[mildred]

I'd better declare first off that I am not a certificated electrician, and my day-to-day work involves sub 230V installations (except where that then feeds inverters - which is a whole other can of worms in installations that also have "mains" inputs).

So far in this discussion of reversed polarity nobody (unless I've missed it - for which apologies) has talked about the potentially (!) lethal effect that appliances bring to the party.

There are at least two important considerations:

1) Appliances are often switched only on the "live" wire. If you have a reversed polarity supply then you're switching on the neutral - and in the event of accident or failure the exposed parts of the appliance could well be "live" with respect to earth even if switched off.

2) Appliances are only fused on the live supply side. (Through the plug top connection and any internal fuses there may be). Again a fault can result in the exposed parts of the appliance being "live" with respect to earth should there be a reversed polarity supply even with a blown fuse.

Given the damp, crowded, accident prone conditions in many vans, I would not trust any unknown supply, and carry both the test gear to check, and the necessary adapter to correct, any reversal.

MildRed

 

[John H]

John i'd have probobly needed one in Bertha as how she was wired reverse polarity could have been a problem if a fault developed, however i doubt one would be required in my new van or indeed any modern van. Now to finish off removing any bits i may need from the old one before i get the new one tomorrow .

Good luck with the new van - can't wait to see it when we get back in the spring.

 

[NicknClair]

Hi Talbot....
I know what a dual pole circuit breaker is, but someone said that all or most European vans would have this.
I wonder if mine has?

In reply to your post *****, European Vans vairy all the time, there is never any consistancy with the builders. We are forever check/modifying/changing AC set-up in motorhomes on a daily basis, inc guys that are still importing from Europe and the States. It is worth noting that most pre 2001 Hymer's we've seen have been single pole MCB with no RCD fitted.

Bottom line is this....................... AC can kill - no question!! We work with an attitude that if it is installed in a manner of polarities being the same, it should have the correct input to suit it's correct operating proceedures.

You should be checking for reverse polarity especially if like some larger vans if transfer switches are used (like on Combi Inverter/chargers etc), sensitive electrical equipment etc etc.

The other thing that concerns us as well is when larger capacity inverters are not protected/installed with correct protection circuits and not integrated to ring main's of the motorhome's in the correct fashion. The worst we see is where the output of the inverter goes direct to the input of the mains on the motorhome, not only is this lazy but it doesn't issolate the mains sockets and keeps other AC equipment connected to the AC line of the van.

Basic protection has already been suggested by previous posts (Polarity Testers, different made-up leads etc, all methods I have used in the past). Bottom line is - do not guess if it will be safe, because one day it won't be and something will happen!! AC electrics are not to be fooled with.

FYI, Best continental socket adapter I found was at a Carreflour Hyper Market, made by CampingGaz of all people and had a quick release change to swap the pos and neg terminals once tested. Cost about 19 euros.

I'm afraid now I'm a bit lazy this day'n'age and got an Auto-Change-over system c/w Earth test built in. I just take a look at the lights to see what it's doing at the time just in case there is no earth present. Has been swapped on the last 2 vans now and is easy to fit, if the mains socket into the van is accessable.

 

[bluepilot76]

How does it affect the charging of the leisure battery?

Hi all.
If I plug my van into the wrong polarity will it damage the van / leisure battery? I have a tester, but when I went abroad I realised reversed might be correct (as my van is a carthago malibu ie german). It seemed ok in France recently (I think the supply was reversed polarity at that site), but then the leisure battery went flat quickly whilst plugged in in Switzerland (I think it was normal polarity there). However in the past I have plugged it in for days in the UK without noticing any ill effects. Then again since nobody is talking about leisure batteries in this discussion maybe it doesn't matter after all and I juust have a fault in my recharging circuit? Any ideas would be welcome. Thanks, Richard

 

[Kontiki]

Hi all.
How does it affect the charging of the leisure battery?

As said before polarity is probably not the correct term as the current on mains hook up is alternating current AC & the charger in your van to your leisure battery is DC. The only issue with the reversed polarity is a safety one regarding the neutral wire can be live & not protected by a fuse or trip.

 

[bluepilot76]

Thanks Kontiki.
In that case I think maybe there was something wrong with the power supply at the Swiss campsite I was at, as the L battery seemed to charge well before that and has done ever since. I hope so anyway!

 

[Byronic]

As has been stated many British M/caravans were fitted with isolation on the live side only, perhaps they still are. To overcome the potential problems,many owners fitted a changeover switch (named RYD) just before the circuit breakers if red warning light came on you just flicked the switch and green safe light came on.

 

[lebesset]

there isn't either negative or positive with A/C by definition
there is phase and neutral

 

[Mick H]

We have always had AC, DC was never really used domestically!!

You young un's!!!
It was used domestically, not far from where you live yourself, in many Derbyshire pit villages, but that was a long time ago, before the national grid.

 

[Talbot Bertha]

You young un's!!!
It was used domestically, not far from where you live yourself, in many Derbyshire pit villages, but that was a long time ago, before the national grid.

Yeah, I realised that after i posted.

 

[Byronic]

But to the layman such as me why do we see Pos (+) and neg (-) on many appliances and instruction manuals
Why a red wire, sorry now brown, with a plus sign and a blue, now black with a neg sign.
Surely everybody refers to them as neg and pos
Well, I do anyway

edit
I think what we may be saying then is that polarity is technically incorrect and is used as a slang term[/

At least we are all (or nearly all) familiar with those terms. The important thing is that with single pole equipment that the fuse is on the phase side, whereas with double pole equipment not so important. What says the only (as far as I can see) Qualified Electrician on the thread.

 

[Deleted member 3011]

The important thing is that some of the problems associated with getting active and neutral back the front in a system that either has no RCD or no double pole switching may only arise when other parts of the protective equipment fail, and even if qualified people explain what the problems are, those not qualified may not appreciate all the ramifications and if they carry out any changes or enhancement based on advice given on a forum like this one, the situation may end up becoming more dangerous.

The result of this is that any professional engineer or qualified tradesman should be very wary of giving such advice to those who may not be able to interpret or implement it correctly and safely.

 

[Byronic]

Agreed, thats why a changeover switch would appear to me to be essential, at least you're sure thats what's coming into your van, and have no control over is easily corrected, if not correct.