Reverse polarity light on. Can I still use charger safely?

[RV-AL]

i am in Spain at the moment, having left my reverse polarity cable in UK! Every site I have stopped at ehu works fine until I switch on inbuilt charger when the reverse polarity sign comes on, so I switch it off again. On a couple of sites they have standard eu socket so I just turn it upside down and all ok. Current site has type 2 connector so can’t do that. It it safe for me to ignore the warning light and charge anyway?

The van is a 2018 auto-trail.

 

[Old Gibber]

Most on site camp sites sell male/female 3pin connectors. Open the male connector and reverse the +&- wires. Label the connector 'Reversed polarity'. Plug it into the site's supply.

... and in so doing, you achieve absolutely nothing.

 

[scotjimland]

No, it goes up to +338v and down to -338v in a sine wave.

correct

AC power, RMS and 3-Phase circuits

RMS and power in single and three phase AC circuits

www.animations.physics.unsw.edu.au

The RMS voltage is 240 volts, so the peak value Vm= V. √2 = 340v

 

[Ingwe]

Don't get caught up in an argument about physics Jim, it goes over the head of most here. The reason I didn't add a current flow description in my answer.

For those not qualified, I will explain. Mains voltage will hurt you by making your muscles contract and kill you as high current passes through your body to Earth, stopping your heart. Funny thing electricity, used wrong will stop a beating heart, used right with a defibrillator can sometimes restart a stopped heart. Not something to be messed with if you are not suitably qualified

People are often shocked when they find out I'm not a very good electrician.

 

[pat100]

What nonsense! There is no reason not to use the onboard mains system with reverse polarity.

Ian

If the charger has a switch could some parts remain live with respect to ground after switching it off? Not saying - just asking

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[bigtwin]

If the charger has a switch could some parts remain live with respect to ground after switching it off? Not saying - just asking

Any device with an on/off switch will have a portion of the device that remains ’live’ after being switched off. With ‘reverse polarity’ the proportion of the device that remains ‘live’ increases significantly.
It should be noted that NONE of this is accessible without taking covers off the device (the notable exception being a toaster where the heating element could be accessible if poked with a metal implement).

All ‘live’ conductors are live with respect to ground but, where potential differences occur a ‘live’ conductor can be ‘live’ with respect to another ‘live’ conductor. If you are at the same potential as a ‘live’ conductor then you would not receive an electrical shock (ie no current would flow through your body). This however is a very unlikely scenario and is probably limited to ‘linesmen’ who work on/suspended from overhead power transmission lines.

Ian

 

[PaulC70]

Under what circumstances do you anticipate needing to check the amperage by poking under the covers of an appliance?

Ian

If you want to check if an appliance is drawing more amps than it should be?

 

[OldCodger]

INDEED IT DOES 120v up 120v down combined gives 240v. Despite quoting RMS average value the actual voltage read across the incoming mains may be higher or lower in different areas. I know a chap in the North East regularly sees 252v on his supply. And another on Bodmin Moor sees 215v. Quoting an average 240v helps people that don't know understand

If I recall correctly (age has put that in doubt) Back in the pre B****t. Days the spec was 230 -6% +13% which put the EU and UK norms in spec. These days are who knows

 

[bigtwin]

If you want to check if an appliance is drawing more amps than it should be?

Generally, if an appliance is drawing more current than it should it blows a fuse.

Ian

 

[ianp]

Don't get caught up in an argument about physics Jim, it goes over the head of most here. The reason I didn't add a current flow description in my answer.

For those not qualified, I will explain. Mains voltage will hurt you by making your muscles contract and kill you as high current passes through your body to Earth, stopping your heart. Funny thing electricity, used wrong will stop a beating heart, used right with a defibrillator can sometimes restart a stopped heart. Not something to be messed with if you are not suitably qualified

Well, while we're on point with the pedantry, a defibrillator isn't for a stopped heart but to allow the body to regulate an irregular rhythm in the heart. A stopped heart ( flatline ) requires CPR ( to start the heart) followed by defibrillation to regulate it if needed.......or so I'm told.
Regarding the European ubiquitous two pin plug, this is a left over from the historically normal system of 2 phase supply that was prevalent through out Europe and elsewhere. As it was a 2 x 120v unreferenced supply then there was no concept of polarity. Apparently there are still a few examples of these systems operating within Europe but the norm now is 220v grounded neutral, effectively the same as ours. The difference being that we grew up with the grounded systems in the days when insulation was relatively poor and the only protection was a very good earth and a fuse that, with the good earth, would blow quick enough to hopefully save you. If you'd reversed the polarity on an old fashioned drill with a metal case and had a poor earth, then having worked the machine hard and burnt out the internal wiring it was quite likely that you would become part of the load as the case becomes live and releasing the trigger switch would have no interruption effect. The poor earth would limit current flow sufficient to shock you but not the fuse and often it would be bye bye you...! Now its all flow balance RCD's and sealed fitted plugs with minimal rating fuses and generally high or double insulated casings.......it's quite hard to get a shock now unless you try!

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[scotjimland]

If I recall correctly (age has put that in doubt) Back in the pre B****t. Days the spec was 230 -6% +13% which put the EU and UK norms in spec. These days are who knows

just the same... it was a paper exercise

the UK supply voltage is, and always has been, .. 240v ..

there was no real change of supply voltage, only a change in the “label”, with no incentive for electricity supply companies to actually change the supply voltage.

 

[bigtwin]

it's quite hard to get a shock now unless you try!

Indeed, but one might imagine with all the paranoia around ‘reverse polarity’ that folks were absolutely determined to try their damnedest. But yet, there is no supporting evidence of this harm occurring.

Ian

 

[Old Gibber]

just the same... it was a paper exercise

the UK supply voltage is, and always has been, .. 240v ..

there was no real change of supply voltage, only a change in the “label”, with no incentive for electricity supply companies to actually change the supply voltage.

Not true. A few years ago I made a fuss because my house voltage was 251/2 volts. Eventually they put sensing equipment next to my meter, took it away and examined the data, then put a more sophisticated sensor on. After this they agreed to rewire the whole hamlet, and the voltage was reduced to 230v. Over time, voltages are reducing from 240v to 230v.

The laugh is that I can remember when they increased the voltage from 220v to 240v, and they came and rewired/altered some appliances, and gave us a guarantee on those that could not be changed. Ho hum.

 

[scotjimland]

Not true.

Not sure why they would have to rewire the whole hamlet to adjust the supply voltage , but in any case it was within the declared voltage tolerance.


In the UK, the declared voltage and tolerance for an electricity supply is 230 volts -6%, +10%. This gives an allowed voltage range of 216.2 volts to 253.0 volts.

The voltage in our property tonight is 239.4 v .. that is the 'nominal' voltage we are normally supplied with .. well within the tolerance ..

The UK supply voltage was never actually changed from 240 to 230v .. as said it was to harmonise with Europe who supply 220v .. so both 220v and 240v supplies were harmonised to 230v

Kitchen worktop socket

 

[PaulC70]

Generally, if an appliance is drawing more current than it should it blows a fuse.

Ian

Yes, generally.
I imagine if an appliance is rated to run at less than 5 amps and keeps blowing the fuse and a 13amp fuse is used, testing to see if it's the appliance drawing more than the rated 5 amps would yield some results I imagine?

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[Petroleumblownapart]

If the charger has a switch could some parts remain live with respect to ground after switching it off? Not saying - just asking

Only if it's a single pole switch!

 

[Petroleumblownapart]

Well, while we're on point with the pedantry, a defibrillator isn't for a stopped heart but to allow the body to regulate an irregular rhythm in the heart. A stopped heart ( flatline ) requires CPR ( to start the heart) followed by defibrillation to regulate it if needed.......or so I'm told.
Regarding the European ubiquitous two pin plug, this is a left over from the historically normal system of 2 phase supply that was prevalent through out Europe and elsewhere. As it was a 2 x 120v unreferenced supply then there was no concept of polarity. Apparently there are still a few examples of these systems operating within Europe but the norm now is 220v grounded neutral, effectively the same as ours. The difference being that we grew up with the grounded systems in the days when insulation was relatively poor and the only protection was a very good earth and a fuse that, with the good earth, would blow quick enough to hopefully save you. If you'd reversed the polarity on an old fashioned drill with a metal case and had a poor earth, then having worked the machine hard and burnt out the internal wiring it was quite likely that you would become part of the load as the case becomes live and releasing the trigger switch would have no interruption effect. The poor earth would limit current flow sufficient to shock you but not the fuse and often it would be bye bye you...! Now its all flow balance RCD's and sealed fitted plugs with minimal rating fuses and generally high or double insulated casings.......it's quite hard to get a shock now unless you try!

Sensible post at last.