Reverse polarity in Europe?

[yorkiebar]

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 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 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.

 

[The Wino]

As you have a continental make of motorhome ( a hymer in your picture) I would have thought it would have double pole circuit breakers and reverse polarity wouldn't be an issue. I have never ever seen any foreign motorhome owners bother with testing for reverse polarity and don't think it's a worry to them it's perfectly normal

 

[autorouter]

I'm assuming these are rhetorical questions so am not responding. I am well aware you are very knowledgeable on electrics and will have clear views on the subject. Why don't you just respond to the op?

So I take it that you and others are comfortable making misleading statements about potentially lethal hazards to newbies asking for advice.

Why do people trot out this false information whenever 'reverse polarity' is mentioned?

 

[The Wino]

So I take it that you and others are comfortable making misleading statements about potentially lethal hazards to newbies asking for advice.

Why do people trot out this false information whenever 'reverse polarity' is mentioned?

How many motorhomes tour continental Europe every summer and how many apart from brits worry about reversed polarity?

 

[autorouter]

How many motorhomes tour continental Europe every summer and how many apart from brits worry about reversed polarity?

If you want to know, European motorhomes have all double pole trips and switches, and the plugs are not fused. They have no need to worry about reverse polarity. UK motorhomes are supposed to be made in a similar way.

However the plugs are fused, and a fuse is inherently a single-pole device. So if a fault occurs in a device, the fuse will blow, but if the polarity is reversed it will be on the neutral wire, so the device will still be live. The fault may be simple, like a failed heater element, and switching off/unplugging an easy option. But the 'fault' may be for example falling over on a chair, and breaking the casing of a hairdryer exposing the live parts. Or any number of unlikely but possible scenarios that those living with kids or old people will recognise.

Also UK domestic electrics are different, with single-pole trips and switches, and some diy converters use these more easily available parts instead of going to the trouble of finding double-pole versions. Because of this, it is important that clear unambiguous advice is available to people asking about motorhome electrics.

I don't 'worry' about reverse polarity, any more than I worry about the motorhome catching fire, or driving into a wall. I take sensible precautions, test the RCD and check the earth connection. And I carry a fire extinguisher and fit a reversing camera and sensors.

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[The Wino]

If you want to know, European motorhomes have all double pole trips and switches, and the plugs are not fused. They have no need to worry about reverse polarity. UK motorhomes are supposed to be made in a similar way.

However the plugs are fused, and a fuse is inherently a single-pole device. So if a fault occurs in a device, the fuse will blow, but if the polarity is reversed it will be on the neutral wire, so the device will still be live. The fault may be simple, like a failed heater element, and switching off/unplugging an easy option. But the 'fault' may be for example falling over on a chair, and breaking the casing of a hairdryer exposing the live parts. Or any number of unlikely but possible scenarios that those living with kids or old people will recognise.

Also UK domestic electrics are different, with single-pole trips and switches, and some diy converters use these more easily available parts instead of going to the trouble of finding double-pole versions. Because of this, it is important that clear unambiguous advice is available to people asking about motorhome electrics.

I don't 'worry' about reverse polarity, any more than I worry about the motorhome catching fire, or driving into a wall. I take sensible precautions, test the RCD and check the earth connection. And I carry a fire extinguisher and fit a reversing camera and sensors.

I know all European motorhomes have proper trips in which case as the ops avatar has a picture of their hymer isn't the straightforward answer in your case don't worry it's only likely to be a problem in an older British motorhome or a home conversion. It answers their question sensibly and without a long explanation?

 

[autorouter]

I know all European motorhomes have proper trips in which case as the ops avatar has a picture of their hymer isn't the straightforward answer in your case don't worry it's only likely to be a problem in an older British motorhome or a home conversion. It answers their question sensibly and without a long explanation?

The point I was making was that it is a problem in all UK or European motorhomes that use UK 3-pin plugs. That is, I think, the vast majority of people likely to be reading this.

As you say, it is potentially more of a problem in older UK motorhomes or DIY conversions. The answer, without a long explanation, is what I said in post #23:

I would advise you to press the 'Test' button on the RCD to make sure it's working properly. If you want, you could use a socket tester in one of your sockets, to test for an earth fault. The socket tester will also tell you if the polarity is reversed, but provided there is a good earth and the RCD is working, the extra hazard of UK electrics plugged into European electrics will be minimised.

 

[The Wino]

The point I was making was that it is a problem in all UK motorhomes that use UK 3-pin plugs. That is, I think, the vast majority of people likely to be reading this.

As you say, it is potentially more of a problem in older UK motorhomes or DIY conversions. The answer, without a long explanation, is what I said in post #23:

But as I understand it you can use 3 pin plugs on appliances safely in a continental motorhome as they have double pole trips. So the briefest answer is in your MH don't worry!

 

[autorouter]

But as I understand it you can use 3 pin plugs on appliances safely in a continental motorhome as they have double pole trips. So the briefest answer is in your MH don't worry!

I completely agree with that, provided the 3-pin plugs are fitted with double-pole fuses.

 

[suavecarve]

I thought reverse polarity was penguins in the arctic

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[bigtwin]

However the plugs are fused, and a fuse is inherently a single-pole device. So if a fault occurs in a device, the fuse will blow, but if the polarity is reversed it will be on the neutral wire, so the device will still be live. The fault may be simple, like a failed heater element, and switching off/unplugging an easy option. But the 'fault' may be for example falling over on a chair, and breaking the casing of a hairdryer exposing the live parts. Or any number of unlikely but possible scenarios that those living with kids or old people will recognise.

But all of that applies equally to foreign unfused plugs, does it not?

Ian

 

[The Wino]

I completely agree with that, provided the 3-pin plugs are fitted with double-pole fuses.

Why would you need a fuse if you have a modern electrical system.

 

[autorouter]

Why would you need a fuse if you have a modern electrical system.

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.

 

[autorouter]

But all of that applies equally to foreign unfused plugs, does it not?

Some of it does. If the wires don't short and produce an overcurrent, you rely on the RCD to trip if someone touches it.

But if it shorts, the European system will trip, disconnecting both wires. The UK system will blow a fuse, disconnecting one wire, which won't be the live if the polarity is reversed.

 

[The Wino]

Some of it does. If the wires don't short and produce an overcurrent, you rely on the RCD to trip if someone touches it.

But if it shorts, the European system will trip, disconnecting both wires. The UK system will blow a fuse, disconnecting one wire, which won't be the live if the polarity is reversed.

Exactly my point about a modern motorhome electrical system don't they all have RCDs that disconnect both wires?

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[LostInSpace]

As you have a continental make of motorhome ( a hymer in your picture) I would have thought it would have double pole circuit breakers and reverse polarity wouldn't be an issue. I have never ever seen any foreign motorhome owners bother with testing for reverse polarity and don't think it's a worry to them it's perfectly normal

The thing is that in the UK our 'mains' electric has live and neutral. As stated above the neutral is connected to earth at the power station so touching it is quite safe.., but the live wire is 230 volts AC which is not at all good for you!

However on the continent they use a system where the two sides of the power are 'center tapped' at the power station so the they are both 115 volts relative to earth (much safer to touch)

So our connections can be reversed but the continental ones can not, which explains why we have switches on the sockets, but they do not.

 

[The Wino]

The thing is that in the UK our 'mains' electric has live and neutral. As stated above the neutra is connected to earth at the power station so touching it is quite safe.., but the live wire is 230 volts AC which is not at all good for you!

True but in my case with a continental motorhome or a British one once they caught up and had double pole RCDs what's the problem?

 

[Barriesimpson]

We have this once in Spain last winter. Just turned the two pin ehu plug up the other way.
I do use a polarity tester, just for some reassurance but not sure I really need to.

That's interesting because, as you know, the plugs in Spain are 2 pin. You can plug in anything, literally anything in either direction as the plug fits fine both ways and the appliance works. There are no indications on the plug as to which way you should plug it in. So basically it makes absolutely no difference whatsoever.

 

[LostInSpace]

True but in my case with a continental motorhome or a British one once they caught up and had double pole RCDs what's the problem?

The problem is actually with older motohomes in the UK. A reversed polarity leaves the switches on the power sockets dangerously misleading. Best to have a reverse polarity checker.

 

[Barriesimpson]

The problem is actually with older motohomes in the UK. A reversed polarity leaves the switches on the power sockets dangerously misleading. Best to have a reverse polarity checker.

But only if you have an old UK spec van I understand. Correct?

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[tonyidle]

Reversed polarity isn't possible on AC mains .

 

[autorouter]

True but in my case with a continental motorhome or a British one once they caught up and had double pole RCDs what's the problem?

it is a problem in all UK or European motorhomes that use UK 3-pin plugs. That is, I think, the vast majority of people likely to be reading this.

 

[autorouter]

True but in my case with a continental motorhome or a British one once they caught up and had double pole RCDs what's the problem?

If the RCD works and the earth is good, then the problem is almost completely mitigated. That's why I said

I would advise you to press the 'Test' button on the RCD to make sure it's working properly. If you want, you could use a socket tester in one of your sockets, to test for an earth fault. The socket tester will also tell you if the polarity is reversed, but provided there is a good earth and the RCD is working, the extra hazard of UK electrics plugged into European electrics will be minimised.

Just because a problem has been solved doesn't mean there never was a problem in the first place. If you can trust your RCD with your life without ever testing it, and you trust every campsite hookup earth, and the earth on your hookup cable, then fine, ignore the problem. But there's no need to say it never was a problem, because that's just not true.

 

[autorouter]

Reversed polarity isn't possible on AC mains .

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'.

 

[autorouter]

But only if you have an old UK spec van I understand. Correct?

Any van that has UK 3-pin plugs. Including any brand-new ones. Older UK spec vans may or may not have extra hazards due to single-pole switches, breakers or lack of an RCD.

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[tonyidle]

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'.

Yes I know all that. I was just trying to subvert the thread

 

[suavecarve]

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'.

I have no idea at all what you just said, but you convinced me that youre right and have gone to the top of my electrical issue solvers list.

 

[David and Sally]

The thing is that in the UK our 'mains' electric has live and neutral. As stated above the neutra is connected to earth at the power station so touching it is quite safe.., but the live wire is 230 volts AC which is not at all good for you!

That's interesting because, as you know, the plugs in Spain are 2 pin. You can plug in anything, literally anything in either direction as the plug fits fine both ways and the appliance works. There are no indications on the plug as to which way you should plug it in. So basically it makes absolutely no difference whatsoever.

Plugged in our EHU lead with the blue plug to two pin conversion. That two pin into the bollard.

The polarity checked showed reverse polarity. Turned the two pin into the bollard upside down and the tester showed ok.

 

[Barriesimpson]

Plugged in our EHU lead with the blue plug to two pin conversion. That two pin into the bollard.

The polarity checked showed reverse polarity. Turned the two pin into the bollard upside down and the tester showed ok.

But it makes no difference.

 

[bigwood]

When we started our motorhome adventures meany years ago we bought adapter leads for all purposes including a reverse polarity adapter.
The only time we found reverse polarity the sockets were two pin so it was easier to turn the plug round.
I thought the French site with a round bollard in the middle of the pitches was bad but a uk site with an extension lead from a barn and six way socket hanging on the fence was dicey.

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