Reverse Polarity - What is it?


A lot of 'scaremongering' surrounds the topic of Reverse Polarity on Caravan/Motorhome websites based on data that is no longer current.


Reverse Polarity is a term usually used to describe where a 230V device, like a household appliance, e.g kettle, has been wired incorrectly at the plug so that the Live/+ power travels down the Neutral/- wire of the 3 wire cable.

Normally the Live/+ voltage would pass down the Brown wire which is where most Appliances have the On/Off switch. 

The Blue wire is used for Neutral and the Yellow/Green wire for Earth. 

It is not an uncommon situation in the UK where somebody fits a 13A plug to, for example, a toaster they have purchased and accidently reverses the wiring so that the 230v Live/+ comes in down the Blue neutral wire in the cable. 

This is reversed Polarity.

Something like a Kettle or toaster will continue to function if connected this way.

However, even when the device works correctly there can be a 'perceived' safety issue as the On/Off switch is sometimes located in the +/Brown cable.

If the Polarity is reversed much of the cable in the device would still be 'live' when 'switched off'. If someone then opened the Case and put their fingers into the wiring, they might be injured. 

Which is why 'standard practice' suggests removal the power supply plug from the wall socket before opening a 230v device and putting your fingers into the wiring. 

Much is made of this 'danger', yet it quite clearly isn't a safety risk as few sensible people are going to open up any 230v device while it is still connected to the wall 230v socket and put their fingers on the bare wires!! 

Almost every appliance going now has labels warning about the Danger of opening the casing of any device while powered with 230v.

To combat this issue of 13A plugs being incorrectly fitted in the Home, new UK regulations were introduced (around 1990?) that specified all Appliances being sold in the UK, had to be pre-fitted with a 13A plug so that purchasers are less likley to fit a 13A Plug with wires/Polarity reversed

Around the same time Appliances began to be 'Double Insulated' and 'double pole' switched, i.e. a switch in both the Live wire AND the Neutral wire. 

UK quality Electronic devices (from say 1999 onwards) began including features to cope with Reverse Polarity by having Double Pole switches and Polarity protected Electronics, following the mainland Europe practice started many years before.   

In France and Spain, they had long ago realised that even when good standards were in place, people did not always follow them in the home. So the majority of French and Spanish manufactured 230v Appliances of the 1970's and 1980's took account of Voltage Polarity reversal and generally worked/were safe on both.

Any Camping Site Electric Hook-Up (EHU) bollard should follow the European 230v wiring standards on all camp sites.

But in the 1980's some French and Spanish camp sites were slow to adopt the more rigidly enforced standards. It had never been a problem before, so some viewed it as unnecessary bureaucracy.

The situation is now very different. Double Insulated, Double Pole switched and Polarity Reversal proof appliances are the norm. 

A modern, quality Motorhome like Auto-Trail, Burstner, Hymer, Dethleffs, N&B, Knaus, etc will happily function on any Polarity and has for about 15 years.  

So while the issue in the 1980's with 'Reverse Polarity' was significant, it is now not the problem it was with a quality, modern Motorhome/Caravan. 

Much of the advice you will read will be old and no longer so relevant.

A Kettle used on the wrong polarity in a Motorhome is no more dangerous than one in the House with the 13amp plug wired incorrectly. 

The risk of using it is zero in real terms.


We are looking to recruit a club member to the team of Directors in a PR role.

Details here

Kevin Lewis, resignation from Board of Directors

See Members Information


French speed limit has been cut… find out what it’s changed to, where it applies and how to avoid fines up to £650

See General Information





See Rally Updates


SUMMER Club Magazine now available for download HERE



Build dates affected 17/02/16 to 03/09/17

See General Information


Joan and Jonathan Taylor raised well over £1100 for 

Motor Neurone Disease 

Stratford on Avon Ralliers raise £81 for Birmingham Childrens Hospital Cardiac Unit

Evesham Ralliers raise over £50 for Birmingham Childrens Hospital

Brixham Ralliers raise £152 for local charity Humanity Torbay

See Welfare and Charity


DoT release updated information on the use of A Frames in the UK

See General Information

ATOCNZ Autumn Newsletter 

See ATOCNZ News and Info


Do you wish to hire out your motorhome or have an exchange with an owner from NZ?

See Overseas Owners


Note for club Rally Stewards 

Please visit Stewards Section in Members Information Section


Tyco BMW's primary British Superbike rider Christian Iddon collects his new 2018 Auto-Trail Comanche'

See Auto-Trail News


Taking your pet dog out of UK? Find a list of breeds banned in some countries.


Safe parking at rallies advice, please take time to read this item.

See Members Information


Auto-Trail -  Where it all began, a brief history.

See Factory News




Join now for just


+ £2.00 one off joining fee

Visit the

Auto-Trail Friendly Group on FaceBook for friendly chat, information and much more

Click the image above

Print Print | Sitemap Recommend this page Recommend this page
© 'AUTO TRAIL OWNERS' CLUB' Auto Trail Owners' Club is a Company Limited by Guarantee, Registered Office:- 22, Beaconsfield Way, Sketty, Swansea SA2 9JR. Company Number: 4702104. COOKIES EU Cookie Legislation. We only use first-party cookies to provide a better browsing experience. We never set cookies for third-party advertisers. Site owned and maintained for Auto-Trail Owners' Club by Dennis Paul