Reversed polarity

Poco Loco

Guest
HI All, Once again I need some help from you more experienced out there. I am due to pick up my first MH in Dec' and head back through France on route to Spain. I understand about Reversed polarity, but I was wondering if it is still a problem with modern MHs i.e does the control panel automatically reverse the polarity if required?

The link below to the caravan club website and the Reversed Polarity PDF gives some information about reversed polarity and suggests making a second connector with the Live & Neutral incorrectly wired in order to reverse the polarity back to the UK norm. My question is how will I know if it is reversed as anything I plug in (TV etc) would automatically correct the polarity and work anyway. I know that if the polarity is incorrect the earth could be the switch and the item left live, but thats only a problem if I'm working on it, in which case I'd just unplug the van and isolate it anyway.

Finally, and probably most important, what connection am I going to need for electric hook up in France? Is it just a French 2 Pin Plug without an earth similar to the Spanish ones?

Thanks once again Thanks in advance for all our help and Tips.

Regards Poco Loco

Overseas advice leaflets | Planning your trip | The Caravan Club
 
the easiest way is never use ehu. ..i fitted it on mine used it while i was building the inside .but havent used it ever while travelling. big waste of money . well i think 50quid for a trip fuses box etc .
 
there is no such thing as reverse polarity
all mains electricity is alternating current

if you have a uk made motorhome it is possible the trip will be on the live connection only , otherwise there will be a trip on both live and neutral
 
Connectors

***** said:
You need a reverse polarity tester (about £7 from caravan shops)
and make up a short lead with the neg & pos reversed and you must clearly mark it accordingly so that it cannot be used when the polarity is normal.
For France most electric hook ups are now the blue three pin round connector, but some of the older sited still use the two pin.
Oh, most vans don't have automatic change over except for very new or expensive vans.
Click to expand...
Thanks *****, Looks like I'll need a whole host of cable variations in order to connect the Tester and Cable to the van. Might be easier to just start up the "Genny" LOL

What array of cables do you use or do you just not plug in?

Regards Poco
 
What is your van? The reason being that continental motorhomes are usually protected by having dual pole trip relays. The only reason I see that 'reverse polarity' being an issue is that a British electric system only trips out on the live wire, this means that if the polarity is reversed then the neutral wire could still be live if the relay has tripped & even the fuse blown, the danger then is if you were to open the plug or appliance while still connected (can't see anybody doing this) then you could get a shock. I assume that having dual pole trip switches also means they don't need to fuse the plugs. I have a polarity tester I bought many years ago but my current van has dual pole relays so it doesn't matter.
 
lebesset said:
there is no such thing as reverse polarity
all mains electricity is alternating current

if you have a uk made motorhome it is possible the trip will be on the live connection only , otherwise there will be a trip on both live and neutral
Click to expand...
I can only second that. We really do have alternative current everywhere on the continent (240 V) for about 60 years now :rolleyes:. You really don't need a polarity tester. (your polarity will only change 50 times /second !)
You'll encounter practically everywhere the bleu EEC-socket. At some places there still are the french-belgian sockets with the neutre-pin (or german ones with side neutre, mostly they go together in one socket - have a plug with a neutre hole + side ones.) A GB-2 pin generally could be plugged in also, but without earth.
 
I agree that reverse polarity is not relavant to AC. My van's control panel warns of RP when charging from a genny without an earth - presumably other RP warnings occur when the earth follows the neutral instead of the line.
 
Another thing that the plug in polarity tester tells you is if the wiring is earthed.
 
lebesset

there is no such thing as reverse polarity
Click to expand...

Yes there is!!!

The biggest problem with reverse polarity on the AC occurs if a fault develops on a 240v circuit because the fuses are efficively in the neutral line, if a line (live) to earth fault develops and the fuse does blow a fault current will still exist because the neutral is now live and is not fused, this can lead to fires as the current could be in excess of the cables rating.
On another note the polarity does not change 50 times a second this is confused with the phase angles rotating between 0 degrees and 180 degrees 50 times a second (50hz) which gives the AC waveform.
So i would suggest using a plug in polarity tester and using a short lead with the brown and blue wires reversed to correct this.
Trust me on this as i am a qualified electrician.
 
reverse polarity

hi poco loco depending on the make of the m/h on the control panel there is a warning light telling you if the polarity is reversed on site also if you connect a generator up to the m/h it will show reversed polarity which we don't pay any attention to . For the sites we have cables made up to suite . happy camping
 
Am I correct in thinking that as my van is built to a continental specification & the trips are dual pole then the reverse polarity isn't an issue as both live & neutral are protected? Would like to have it confirmed by a qualified electrician.

BTW I found the easiest way to sort out the 'plugs' issue is to buy them in the country you are in.
 
Fleming said:
I can only second that. We really do have alternative current everywhere on the continent (240 V) for about 60 years now :rolleyes:. You really don't need a polarity tester. (your polarity will only change 50 times /second !)
You'll encounter practically everywhere the bleu EEC-socket. At some places there still are the french-belgian sockets with the neutre-pin (or german ones with side neutre, mostly they go together in one socket - have a plug with a neutre hole + side ones.) A GB-2 pin generally could be plugged in also, but without earth.
Click to expand...

We have always had AC, DC was never really used domestically!!
 
Kontiki said:
Am I correct in thinking that as my van is built to a continental specification & the trips are dual pole then the reverse polarity isn't an issue as both live & neutral are protected? Would like to have it confirmed by a qualified electrician.
Click to expand...

If the outlets are protected via a dual pole trip then if this trip activates you are fine but if the fault just blows the fuse at the appliance (in the plug) then the fault could still exist at the appliance. Double insulated equipment such plastic kettles dont have an earth so would be fine but if its metal then it would be earthed so could potentially become live.
 
Those who maintain that there is no such thing as reverse polarity in mains supply may be correct according to some strict (and irrelevant) definition based on DC supplies, but it might be better if they kept their own council rather than suggesting that there is never a practical reason to worry about when hooking up to a pedestal with active and neutral conductors transposed.

And as for hooking up to outlets with no earth ......

{talking about normal mains supplies, not generators or fully-isolated inverters. These last two are special situations and the earth may not even be connected so normal "rules" may not apply}

BTW - regardless of the advisability of connecting your van to an unearthed socket in a campground, those visiting Morocco may have a simple choice - unearthed outlet or nothing. Continental spec'd motorhomes with RCDs (earth leakage breakers) operating in both active conductors still provide some measure of safety, but I hate relying on safety gear as the first line of protection.
 
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Tony Lee said:
Those who maintain that there is no such thing as reverse polarity in mains supply may be correct according to some strict (and irrelevant) definition based on DC supplies, but it might be better if they kept their own council rather than suggesting that there is never a practical reason to worry about when hooking up to a pedestal with active and neutral conductors transposed.

And as for hooking up to outlets with no earth ......
Click to expand...

Reverse polarity on DC does exist that is why problems occur on older cars (Read very old) with a positive ground chassis and modern equipment. Put the battery in backwards in any DC equipment and it shouldnt work. Either way always pay attention to the polarity of any connection be it AC or DC due to the fuses being on the live or positive leg.
 
Polarity Warning Light on with a Genny

syldale said:
hi poco loco depending on the make of the m/h on the control panel there is a warning light telling you if the polarity is reversed on site also if you connect a generator up to the m/h it will show reversed polarity which we don't pay any attention to . For the sites we have cables made up to suite . happy camping
Click to expand...

When I get the hand over for the MH I will ask the question about the Reversed Polarity Warning light. I didn't know that the warning light would illuminate with a "Genny". Any idea why this is so? I thought 240v with the correct polarity is 240 with the correct polarity, whether from the mains or a generator?

Regards Poco Loco
 
Could be because the generator is not really earthed. Try using an earth spike connected to the generator chassis this may cure it.
 
you are correct , negative polarity does exist ,but in DC

reversed polarity is correctly defined as when the positive cable is connected to the negative terminal and vice-versa

as there are neither positive nor negative cables with A/C current , but phase and neutral , perhaps the expression reversed phase and neutral would describe what has happened

but to fit a trip which operates only on the phase cable is illegal in most countries , can't say if it would still be permissable in the UK
 
lebesset, If the Line (Phase) and Neutral conductors are reversed in AC (Single phase 240v) it is still referred to as reverse polarity(Even though technically AC has no polarity). AS i stated in an earlier post this is a problem if a line to earth fault occurs on a load (appliance) the fuse locally in the plug can blow but due to the line and neutral being reversed this has no effect and the fault still exists causing fires electrocution, death, a rupture in space time and all other manner of events that make you wish you had observed the polarity of your supply......


Most circuit breakers fitted to domestic distribution boards only break the Line conductor, RCD's break both the Line and Neutral.

*****, mains wont overload on the neutral side only the line (live) side. Double pole breakers are used to disconnect the supply completely as this is safer just incase a reverse polarity situation exists.
 
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