Reverse polarity in Europe? (5 Viewers)

[stevewagner]

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'.

Great explanation but actually UK supply is referred as 230 volts since European harmonisation in 2003, although there has been no actual change in reality.

 

[LostInSpace]

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

The tester has to make a choice. It only has two options. But, technically neither is correct.

 

[Pausim]

Great explanation but actually UK supply is referred as 230 volts since European harmonisation in 2003, although there has been no actual change in reality.

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.

 

[bigtwin]

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.

What happened was that they defined a harmonised voltage with plus and minus limits that meant nobody had to change anything technical, so, effectively, you're correct.

Ian

 

[David and Sally]

But it makes no difference.

It made a difference to the lights on the tester.

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[CAB96]

But it makes no difference.

They have a UK van with UK sockets, which as Autorouter explained above, are switched only on the UK live.

Reverse polarity means, as I understood it, the neutral becomes switched, and the UK sockets would have permanent live.

That's normal practice for a Continental motorhome, as I understand it, but not for a UK van.

 

[David and Sally]

What happened was that they defined a harmonised voltage with plus and minus limits that meant nobody had to change anything technical, so, effectively, you're correct.

Ian

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

 

[David and Sally]

On another UK v EU topic. What do UK manufacturers insist on the van switching off the 12v hab electrics when the engine is running?

 

[Coolcats]

Here is a question if polarity in France is 50/50

Has anyone actually been adversely affected by this, I suspect probably not but would be good to hear if anyone has.

Or is this just a storm in a MoHo tea cup

 

[bigtwin]

Here is a question if polarity in France is 50/50

Has anyone actually been adversely affected by this, I suspect probably not but would be good to hear if anyone has.

Or is this just a storm in a MoHo tea cup

It is reasonable to assume that The level of threat posed will be directly reflected in the number of deaths/injuries occurring on sites. The absence of such publicity would tend to suggest that the threat is low.

Ian

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[Pausim]

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

We must have agreed to it.

 

[Pausim]

On another UK v EU topic. What do UK manufacturers insist on the van switching off the 12v hab electrics when the engine is running?

Because the NCC doesn’t know the difference between a caravan and a motorhome.

 

[David and Sally]

We must have agreed to it.

We were part of that mob at the time. No alternative.

 

[bigtwin]

Because the NCC doesn’t know the difference between a caravan and a motorhome.

Exactly this

Ian

 

[David and Sally]

Because the NCC doesn’t know the difference between a caravan and a motorhome.

Thanks, but really doesn’t give me the reason why a caravan or motorhome should need 12v switching off.

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[bigtwin]

Thanks, but really doesn’t give me the reason why a caravan or motorhome should need 12v switching off.

In the case of caravans (for which the code was created) any fault occurring during towing would not be readily detected because the unit is unoccupied. The need for isolation is considered, rightly or wrongly, to be a safety issue.

Ian

 

[autorouter]

Thanks, but really doesn’t give me the reason why a caravan or motorhome should need 12v switching off.

For any vehicle, it must be tested so that any electrical devices do not cause problems when the vehicle is travelling. So any devices must be tested for compatibility while the engine is running. European manufacturers do the testing. UK manufacturers don't. They prefer to simply ensure that all habitation devices are automatically switched off when the engine is running.

 

[The Wino]

All this stuff about our plugs being fused on the live side only does it make any difference in terms of risk of people being electrocuted? I thought a conventional fuse wouldn't blow in time. I'm with those that would like to know any firsthand experience of anyone adversely affected by reverse polarity as others have said it's going to be present on lots of supplies abroad where are those affected?.
I used to see someone at work who blamed reverse polarity for the battery going in his caravan almost certainly totally unrelated are those the sort of stories that make people worried about reversed polarity or are there real cases that it's caused a problem.

 

[autorouter]

All this stuff about our plugs being fused on the live side only does it make any difference in terms of risk of people being electrocuted? I thought a conventional fuse wouldn't blow in time.

If the fuse blows, everything is still live. So the fuse protection does not make things safe.

 

[bigtwin]

If the fuse blows, everything is still live. So the fuse protection does not make things safe.

But why is this considered less safe than a device that has a continental plug that doesn’t have a fuse (where everything would also still be live)?

Ian

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[Coolcats]

It is reasonable to assume that The level of threat posed will be directly reflected in the number of deaths/injuries occurring on sites. The absence of such publicity would tend to suggest that the threat is low.

Ian

I agree and if that’s how it is one sites I suspect it’s the same in residential buildings

 

[The Wino]

I agree and if that’s how it is one sites I suspect it’s the same in residential buildings

I know people always used to say continental electrical systems were dodgy as they had ordinary switches and sockets in bathrooms presumably because their circuit breakers etc were double poll and inherently safer!

 

[autorouter]

But why is this considered less safe than a device that has a continental plug that doesn’t have a fuse (where everything would also still be live)?

If there's an overcurrent fault, the 16A double-pole MCB will trip. In the UK plug, the fuse is of course single pole.

 

[bigtwin]

If there's an overcurrent fault, the 16A double-pole MCB will trip. In the UK plug, the fuse is of course single pole.

But that’s unrelated to the appliance, that’s part of the 250V supply infrastructure.

On a given vehicle, a 13A plug cannot be less safe than a continental plug which is what you’ve been suggesting on a number of posts in this thread.

Ian

 

[Pausim]

But that’s unrelated to the appliance, that’s part of the 250V supply infrastructure.

On a given vehicle, a 13A plug cannot be less safe than a continental plug which is what you’ve been suggesting on a number of posts in this thread.

Ian

What makes it less safe is that it gives a false sense of security by leaving the appliances appearing to be safe when it is not. This does not happen if there are no single pole switches and fuses allowed.

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[bigtwin]

What makes it less safe is that it gives a false sense of security by leaving the appliances appearing to be safe when it is not.

But, in a given van, it CANNOT, be less safe than a continental plug.

It is a separate argument to say that no van should have single pole protection but that is not the point that I’m addressing.

Ian

 

[Pausim]

But, in a given van, it CANNOT, be less safe than a continental plug.

It is a separate argument to say that no van should have single pole protection but that is not the point that I’m addressing.

Ian

I am not sure what a given van is but I know that on my van the 13A plug is the only part of a circuit that has a single pole fuse/switch that could leave an appliance appearing to be dead when it might still be live. It makes even less sense when using my inverter because I know that it puts 115V down both wires which only achieve 230V when the 2 out of phase supplies meet at the appliance, putting a fuse on half the supply makes no sense to me.

 

[Spriddler]

I used to manufacture high power public address systems but had severe competition from cheap Korean products so we got a few in to inspect them. All were 'CE' marked (a self-certification process) but all had single pole mains switches with a fuse in the Neutral line.

 

[bigtwin]

I know that on my van the 13A plug is the only part of a circuit that has a single pole fuse/switch that could leave an appliance appearing to be dead when it might still be live.

And if that appliance had a continental plug on it, how could that be safer than your 13A plug?

Ian

 

[The Wino]

I am not sure what a given van is but I know that on my van the 13A plug is the only part of a circuit that has a single pole fuse/switch that could leave an appliance appearing to be dead when it might still be live. It makes even less sense when using my inverter because I know that it puts 115V down both wires which only achieve 230V when the 2 out of phase supplies meet at the appliance, putting a fuse on half the supply makes no sense to me.

Just thinking about that why would it be a concern to have reversed polarity and go to the faff or testing and a lead to reverse it and then when off site be happy with power from an inverter with both wires in effect live!

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