Bongo Fury

Whilst stocking up on gear from the camping shop for a trip to the continent an assistant tried to advise me to buy a reverse polarity detector, to test hook ups are wired correctly, I suspected opportunist selling, are they needed and if so what use are they?

Hi
They usually are a plug that just LITERALLY plugs into the outlet to check if the connections are correct...They might seem a bit of a sales gimmick if you've not heard of them, but they're essential if you want to avoid damage to your equipment...It's fairly common to find incorrectly wired points abroad, and VERY common in the old ex-Commie countries
Cheers
Helen

Some RCD trip units used on conversions have a built in indicator such as this one: http://www.ebay.co.uk/itm/Caravan-Mains ... 1057888355

Reverse polarity in itself is unlikely to do any damage to equipment but the problem is that most switches on sockets and appliances have the on/off switch in the live connection. If the polarity into the vehicle is wrong then when something is switched off it will still be live as the switch is now in the return/neutral connection.

If you get a revese polarity tester, then you'll also need a cross-wired plug/socket lead to correct any problems found: http://www.ebay.co.uk/itm/Mains-Reverse ... 35d753b5d9

For the price I recon it's well worth having.

http://www.amazon.co.uk/Winner-Mains-Po ... B002QW3SL8

And you will probably need a 2pin (continental type plug) to the normal 3pin type.
Also remember to check the polarity before you plug the van in.
In Spain a couple of months ago we had the reverse polarity and the 2/3 pin adapter on.