reverse polarity question

[oldun]

What I'm trying to work out is what kind of technology are they using in France on their hook up post, that tells it that an Englishman is plugged inoh:
It seems to me that only the English are worried about reverse polarityoh:
So why don't it Kill the French:Cool:
Because it don't really matter do it
Geo

There is one real problem with reversed polarity. If you are on reversed polarity the switch is normally only in the return line so that you cannot truly switch off any such apparatus in the van.

If you have a piece of built in equipment that electrically fails then the rcd will trip switching off the power and making it safe.

So what's the problem. Well it's this - as you cannot switch off the offending piece of equipment (switch in the return line) then you cannot isolate it from other electrical equipment and so the rcd will always trip and all your electrical equipment will be unusable.

With correct polarity you can just switch off the offending item and carry on using all the other equipment.

 

[Jaws]

With Geo and Mike and do not care who says what.. For my sins I have got a lot of silly meaningless letters after my name which is supposed to indicate what a clever fellow I am when it comes to electronics ( but of course that is electronics and not electrical installations ) .. Said letters and bullpoo that comes with them does not make me right either !

AC is, in simplest terms, an electromagnetic pulse whose amplitude is switched from the +ve to -ve side of a datum line.

I think folk today have forgotten the very basics.. the reasons the UK and almost every other civilised country uses AC rather than DC ( and yes, there were LOTS of countries who used DC, some like the USA up until quite late in the over all scheme of things.. well in to the 1900's if memory serves me well )

In fact if it was not for the efforts of Tesla and his team that situation may have remained unchanged for many more years.

There are a few reasons AC is preferred over DC, convenience, ability to transform with ease, low losses in transmission lines, safety ( in that it tends to throw off rather than hold on

and........ ( quote )

AC supply voltage is used for various safety reasons ONE OF WHICH IS INADVERTENT REVERSE CONNECTION WILL NOT BE PARTICULARLY DANGEROUS

( my capitals )

AC it swings both ways... ( oooeerrrrr missus ! )

Whilst it does make a difference as to which is a feed and which a return, as far as I am concerned it makes no odds

Happy to say go with a man who says it is dangerous ( it says it is in health and safety books ) as no matter what I or anyone thinks, that advise cannot be wrong.
But me, ?
I shall continue to not give a bugger

As it happens, I do have one of those polarity testers.. use it just for something to do to see how many posts ARE the right or wrong way round but rarely if ever bother to 'correct' if found 'wrong'

As asked elsewhere and to paraphrase.. how many french, spanish, german or whatever do you see laying twitching beside a glowing van ????

 

[RKE]

With Geo and Mike and do not care who says what.. For my sins I have got a lot of silly meaningless letters after my name which is supposed to indicate what a clever fellow I am when it comes to electronics ( but of course that is electronics and not electrical installations ) .. Said letters and bullpoo that comes with them does not make me right either !

AC is, in simplest terms, an electromagnetic pulse whose amplitude is switched from the +ve to -ve side of a datum line.

I think folk today have forgotten the very basics.. the reasons the UK and almost every other civilised country uses AC rather than DC ( and yes, there were LOTS of countries who used DC, some like the USA up until quite late in the over all scheme of things.. well in to the 1900's if memory serves me well )

In fact if it was not for the efforts of Tesla and his team that situation may have remained unchanged for many more years.

There are a few reasons AC is preferred over DC, convenience, ability to transform with ease, low losses in transmission lines, safety ( in that it tends to throw off rather than hold on

and........ ( quote )

( my capitals )

AC it swings both ways... ( oooeerrrrr missus ! )

Whilst it does make a difference as to which is a feed and which a return, as far as I am concerned it makes no odds

Happy to say go with a man who says it is dangerous ( it says it is in health and safety books ) as no matter what I or anyone thinks, that advise cannot be wrong.
But me, ?
I shall continue to not give a bugger

As it happens, I do have one of those polarity testers.. use it just for something to do to see how many posts ARE the right or wrong way round but rarely if ever bother to 'correct' if found 'wrong'

As asked elsewhere and to paraphrase.. how many french, spanish, german or whatever do you see laying twitching beside a glowing van ????

I agree with most of the above apart from the 'throwing off' bit!

AC will contract your muscles, and so you will be unable to 'let go'

DC will be more likley to 'throw you off' .......

 

[billkce]

There is one real problem with reversed polarity. If you are on reversed polarity the switch is normally only in the return line so that you cannot truly switch off any such apparatus in the van.

If you have a piece of built in equipment that electrically fails then the rcd will trip switching off the power and making it safe.

So what's the problem. Well it's this - as you cannot switch off the offending piece of equipment (switch in the return line) then you cannot isolate it from other electrical equipment and so the rcd will always trip and all your electrical equipment will be unusable.

With correct polarity you can just switch off the offending item and carry on using all the other equipment.

aaaaaarrrrrrgggggghhhhhh!!!!!!!!!!!!!!!!!!!!!!

 

[Jaws]

Sorry, yes RKE, you are of course spot on mate.. its an age thing ( I think I am 9 LOL !! )

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[scotjimland]

Some interesting reading on the effects of AC and DC current on the body

http://www.allaboutcircuits.com/vol_1/chpt_3/2.html

 

[beachcaster]

There are less reports of people getting electrocuted than gassed

Loddy

What are you saying ?? OH NO ..... There are now gangs of east european romanies running around electrocuting people as they sleep ?????

Yikes



Really enjoyed this thread....educational.

barry

 

[aba]

Some interesting reading on the effects of AC and DC current on the body

http://www.allaboutcircuits.com/vol_1/chpt_3/2.html

after reading through that link jim it seems that putting an earth spike on a generator is a good idea.

 

[jonandshell]

If it wasn't for our silly electricity supply, none of this would be an issue! I mean, fancy using the earth as a return conductor so that you immediately die if you touch a live wire! The health and safety man would ban it if our grid were invented today!
I suppose our SWER grid system saves on cables though.
We don't have a seperate EHU cable in our van, we use a quick-release plug which facilitates easy cable-swapping!

Link Removed

The EHU post could have been wired by a colour-blind meerkat and we are still easily able to get it right quickly by observing our socket tester!

 

[jonandshell]

Besides, get a decent battery and you won't have to go out in the rain with your hookup lead, or worry about it's polarity!!!!!

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[pappajohn]

following on from Jims link...THIS...explains how we get a shock via earth.

in a perfect world we don't need an earth at all and may be better off without one in certain circumstances.

take an onboard generator......there is no direct connection to the ground by either the gennie or van so providing there can be no accidental connection you wont get a shock by grabbing a live conductor but as most gennies have a center tap earth connection inbuilt the possibilty of a shock is high via the vans chassis earth or appliance earth

providing your van is fitted with an RCD breaker/main switch, which should disconnect in 30milliseconds, there is little chance of getting a fatal shock anyway....30 milliseconds is faster than one complete 50hz mains cycle