How surge protectors work

[paul_uk]

I'm moving to France and I've been reading up on putting French plugs on UK appliances and I noted that it is not uncommon for the live and neutrals to be switched on sockets. I also read that power surges are more frequent here and surge protectors are a good idea for sensitive equipment.

From my understanding surge protectors work by monitoring the live. So if the live and neutrals were swapped at the socket would devices be protected? I'm interested to know as I am intending to adapt UK ones and I was wondering whether they are different to French ones.

Can anyone help with the theory?

 

[Lucien Nunes]

Normal surge-protectors as found in electrical accessories are usually symmetrical and have the same protection for both line and neutral conductors (both of which are termed 'live conductors' in modern parlance). Therefore the protection is not compromised by reversed polarity. Whether surges are more prevalent will depend on the kind of supply network you are connected to and will vary by location just as it does in the UK.

Avoid using fused UK electrical accessories in Continental Europe, as there is a chance of the fuse ending up in the neutral due to reversed polarity accessories, which can cause an appliance to appear dead when it is still live. The MCBs in any modern French consumer unit will control both poles and hence when it trips, the appliance will be dead. That said, French CEE7/5 sockets are polarised and there is a convention (the same as ours, neutral on the left when the earth is uppermost) and most electricians will be wiring them correctly. Schuko sockets are different inasmuch as they are not polarised at all, for valid historical reasons.

 

[Pete999]

How Surge Protectors Work - HowStuffWorks
Try this for size

 

[Lucien Nunes]

Pete I just had a 30 second skim through that article and spotted a number of errors and bad explanations, so wouldn't recommend it much as an information source. In any case I am not sure that its diagrammatic representation of single-pole protection by MOVs is at all representative of EU practice (or US for that matter, as the unit in the photo appears to be double-pole).

There's a lot of myths around surge protection. I spotted one even in this:
http://www.emersonnetworkpower.com/...30119_surgereferenceguide_11-11_singlepgs.pdf

 

[paul_uk]

Thanks for your responses. It was articles like HowStuffWorks that made me think only a single line was protected.

I'll still stick with my plan of using a UK surge protector with a French plug safe in the knowledge I'm protected. When you say that using a fused plug "can cause an appliance to appear dead when it is still live", I assume you mean if the fuse blows and is on the neutral line then the appliance will not work but it is still attached to the live wire? However if CEE7/5 convention is followed then this shouldn't be an issue?