# Double Dutch & Reverse Polarity?



## 98585 (Apr 9, 2006)

My handbook on a new Autotrail says this...

*Overseas Connections
Connection to mains voltage
overseas requires particular
attention. Electricity supplies abroad
may be of reverse polarity.The
significance of this is that when an
appliance is switched off, it may not
be electrically isolated.
It is useful to check to polarity of
the supply so that the connection
can be made neutral to neutral and
live to live as recommended.Your
Auto-Trail, however, is fitted with a
double pole circuit breaker.
Check that all motor home
equipment is set to accept the site
supply prior to switching it on.I]*_

I have no idea what they are on about. So my tech Question is. With a new EC200 RCD thingymeebob Do I need one of those switched over polarity spare plug thingys?

Thanks in anticipation_


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## geraldandannie (Jun 4, 2006)

See the thread >> HERE << Jim - "Reverse Polarity on Campsites". :wink:

Gerald


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## 98585 (Apr 9, 2006)

Hi Gerald,

Yes, sorry, I have just seen that thread, but it doesnt answer my question. The bit in my handbook that I dont understand starts 

"Your Auto-Trail, however,...."

Does this mean I dont have to worry about Reverse Polarity? 

thanks


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## cabby (May 14, 2005)

Basically for peace of mind you need to buy two items.1/. a reverse polarity tester; this plugs into your 3pin mains socket inside your van, it will use coloured lights to display if the connection is reverse polarity or not. 2/. is a reverse polarity adaptor that connects between the end of your hook up cable and the site socket, normal about 12 inches. should the tester display show that this needs using.most accessary shops will stock these items. 
This will ensure the same standard of safety where ever you are.does this help you.


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## 98937 (Apr 28, 2006)

As I understand it, as you have a double pole isolator you will isolate both live and neutral supplies coming into the van. Therefor you will be safe!
But get an adaptor anyway.


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## Fatalhud (Mar 3, 2006)

Although they are saying your van has a double pole breaker which means the live and the neutral will be isolated when it switches off
this doesnt stop the fact that the polarity may be reversed
most appliances will cope with this but it is good practice to ensure the correct polarity
play safe and buy a plug in tester and have a reversed polarity plug at the ready


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## sallytrafic (Jan 17, 2006)

I'm not sure which bit you think is double dutch it seems Ok to me so lets break it down:
_*Overseas Connections 
Connection to mains voltage overseas requires particular attention. *_

There may be a problem abroad

_*Electricity supplies abroad may be of reverse polarity.*_

The Live and Neutral may be swapped

_* The significance of this is that when an appliance is switched off, it may not be electrically isolated. *_

Some equipment, sockets etc only switch the live wire if they are swapped then its the neutral wire that is switched. The device will be 'off' but still connected to 230V.

_*It is useful to check to polarity of the supply so that the connection can be made neutral to neutral and live to live as recommended.*_

Checking the supply will tell you if there is a problem

_*Your Auto-Trail, however, is fitted with a double pole circuit breaker. Check that all motor home equipment is set to accept the site 
supply prior to switching it on.*_

With the two pole circuit breaker in the off position both live and neutral is switched off so regardless of whether the supply is swapped so you are safe when it is off. You should check the polarity of the incoming supply before turning it on.

As most polarity testers plug into a 3pin 13A socket this means that you would need to have an adaptor at the end of your mains hookup wire to plug your polarity tester into. What most people do in practise is plug the tester into a spare socket on the van, switch on briefly to check the polarity then make any changes necessary.

If you still have a problem with understanding this then I would get someone to show you before undertaking any modification.

Regards Frank


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## Fatalhud (Mar 3, 2006)

you can buy polarity testers with 16amp blue plug fitted


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## dwwwuk (Dec 31, 2005)

My EC200 in a Bessacarr E795 has a reverse polarity indication I believe so you may not need to purchase a separate one. Have a look on your EC200 unit and you may see a reverse polarity light.

Hope that helps,

Kind regards,

David.


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## geraldandannie (Jun 4, 2006)

Just remembered - one of the magazines (Practical Motorhome?) installed a polarity changer in a van. Can't remember whether it was automatic or not - I think it was.

Gerald


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## spykal (May 9, 2005)

Polarity changer <<<


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## sallytrafic (Jan 17, 2006)

Anyone got any technical details of the weird supply I was offered in Norway. It said all was well ie all three neons on my tester. I then inverted the plug (shucko type) expecting to swap live and neutral and it was still ok! Since my return I have been meaning to find out how it is possible to fool the tester.


Regards Frank


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## spykal (May 9, 2005)

Hi frank

It was probably "green" electricity from one of the many hydro electric installations that they have in Norway...as such it must have got confused when asked to travel down either the red or black wires in your van and your tester just lit up out of sympathy.

Mike

P.S. I would get a new polarity tester :wink:


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## geraldandannie (Jun 4, 2006)

I think that's the kiddie, Mike. Not an automatic job. I bought a chcker from Maplin (£3.99) and cable and two connectors from Wickes (about £10). I figure when I hook up, it only takes a few seconds to check and put the swapover cable in.

Note to self - must make UK mains -> blue adapter cable

Gerald


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## spykal (May 9, 2005)

Hi Frank

...maybe the supply was in fact a split phase supply....two phases of a three phase supply. This may sound daft but it could happen if the person wiring the setup was a fool....the voltage available would be much higher ( around 350-400 volts) but it is still a possibility that this was the situation. Did you use any 240 volt equipment? I have not tried to work out what the polarity tester would have made of this or the effect on your charger:roll: ...any experts comment?

Mike


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## geraldandannie (Jun 4, 2006)

I think it depends on both the tester and the charger. The tester might have been OK, but I suspect the charger would have gone kaput. Appliances generally do when you stuff 440 up them. Don't ask me how I know  

They don't have 220V 3 phase in Norway, like they do in the US? Just a thought. Unlikely.

Gerald


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## xgx (Oct 14, 2005)

gerannpasa said:


> Note to self - must make UK mains -> blue adapter cable
> Gerald


Make two... one so that you can plug into UK mains and another with a socket so that you can also use the hook up lead as an extension cable :wink: 
(trusting you know how... if not, consult a qualified electrician 8) )


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## geraldandannie (Jun 4, 2006)

sng said:


> Make two... (trusting you know how... if not, consult a qualified electrician 8) )


Thanks, Graham. I already have the UK mains to M/H cable, so I can charge the battery at home. It's the other one I need to make. And no problem with making it, thanks, but a very pertinent warning :wink:

Gerald


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## sallytrafic (Jan 17, 2006)

spykal said:


> Hi Frank
> 
> ...maybe the supply was in fact a split phase supply....two phases of a three phase supply. This may sound daft but it could happen if the person wiring the setup was a fool....the voltage available would be much higher ( around 350-400 volts) but it is still a possibility that this was the situation. Did you use any 240 volt equipment? I have not tried to work out what the polarity tester would have made of this or the effect on your charger:roll: ...any experts comment?
> 
> Mike


Tester still ok and will detect reverse polarity. I didn't use supply but plenty of others were using it. I read somewhere that there were supply systems in Norway that were a completely different from TNCS TNS or TT supplies etc that we are familiar with. Note this camp was in the far North and at the edge of a town ie not in some farmers field.

Frank


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## peedee (May 10, 2005)

Have you not missed a point here? Is this two pole circuit breaker a manual switch or an automatic device which trips in case of a fault. If the latter then it MAY be ok not to bother about reversals. Myself, I would still not trust it (there are different types and they can always go faulty) and I agree with cabby's quote below.



cabby said:


> Basically for peace of mind you need to buy two items.1/. a reverse polarity tester; this plugs into your 3pin mains socket inside your van, it will use coloured lights to display if the connection is reverse polarity or not. 2/. is a reverse polarity adaptor that connects between the end of your hook up cable and the site socket, normal about 12 inches. should the tester display show that this needs using.most accessary shops will stock these items.
> This will ensure the same standard of safety where ever you are.does this help you.


peedee


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## epavelin (May 19, 2005)

Most of the campsites we were at in Norway this year showed "No Earth" on our mains tester, which was more than slightly worrying... never had this problem anywhere else. Anyone else experienced this?


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## spykal (May 9, 2005)

Hi

Found this ...please remember it came from the web :roll: 

The method used by Norway is known as the IT System and the only things grounded are the metal casings and parts at the load, which share a common ground line NOT bonded to the neutral. Norway uses it 
particularly because the earth* has very low conductivity.


I have seen references to this system being used in hospitals too...I guess because it is safer or there is less chance of sensitive equipment getting affected by earth voltages.


Mike

* as in The Earth ..the ground ?


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## peedee (May 10, 2005)

epavelin said:


> Most of the campsites we were at in Norway this year showed "No Earth" on our mains tester, which was more than slightly worrying... never had this problem anywhere else. Anyone else experienced this?


Yes, see my report on our last trip to Norway which is on my web site.
I have also come across it on a few sites in France.

peedee


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## Scotjimland (May 23, 2005)

Instead of making up three (or more) different reverse polarity adaptor leads for France, Spain and the UK make just one using a male and female 16a blue plug and socket for the 'van' end of the cable...


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