Spd's

[Steve3948]

Well after reading an article in the ECN regarding the use of SPD's where the writer who happens to be the person responsible for development of marketing within the commercial market segments for Hager, where he feels all domestic installations in his opinion should have a SPD fitted.

What are your thoughts, I have never fitted one in a domestic installation or felt the need to based on only ever hearing of one instance maybe 10 years ago where it would have helped.

Commercial/Industrial in certain environments is a done deal, but domestic is this just another money spinner, thoughts please.

 

[Evans Electric]

Knowing what an SPD is would help , Steve .    Excuse my ignorance but we have so many of these things now I lose track .

 

[OnOff]

Thinking out loud here..........lightning strikes affecting the incoming supply............would SPDs be useful in that case? Here's a random one on the lightning front........is a TT install MORE susceptible? 

 

[Steve3948]

Yes and Yes, thats the main selling point.

However do we in this country really get enough of that weather to warrant them.

I've read that in other countries its very much needed where thunder and lightning happen on a regular basis and a lot of properties are fed overhead. However I've only met one domestic person in 40 years of being in the trade that has been subject to damage caused by a surge.

So its down to the designer of the installation to assess if its required or not.

More hassle, more to go wrong, thats how I see it.

 

[OnOff]

I "know" a guy who swears blind that whilst working on a TN-S ring circuit with the fuse (yes fuse) removed and in pocket and face plates off there was a storm overhead and what felt like a bolt striking close by, as in shook the house  and a WTF moment.

Had a visible blue "spark" a few inches long come out from the "bare ends of the T&E" at him.................didn't look too close and waited for the storm to pass!

Guessing not from the Line as fuse removed......or could it jump the gap? So much for "safe" isolation although I suppose throwing the main DP switch would have broken the N.

 

[apprentice87]

Surge protectors = waste of money. There is, or was, a section in the regs concerning protection from lightning, but it explained in the regs. [red book] that it was not required in the UK as we did not have enough lightning, less than 25 a year, whereas all the other european countries have a lot more..

As to big sparks; When i was a kid years ago, there was lightning one day, and a big blue flash and a crack came out of the plug socket the telly was plugged in. Not sure what arced to where though, as the plug was in the socket [telly was off by the way] Did not appear to hurt the telly though or the socket!!!

john..

 

[OnOff]

Risk vs cost then to a large extent. How much would domestic surge protection cost? And.........do you protect all conductors?

EDIT: I use Gil-Lec myself for Hager. If I'd have known SPD's were so cheap I'd have ordered one with every cu........

http://www.youtube.com/watch?v=iHFMB5orgk8

 

[pewter]

I have a customer with an over head TT supply. They have had to replace quite a few appliances after power cuts and storms. I don't think they have actually been struck by lightning but have an over voltage issue when the power comes back on.

I did start to look into getting an SPD for them but all the ones I looked at were not suitable for a TT supply.

 

[Sidewinder]

SPD's are more necessary on TT FFS!

Not your fault, but what the heck are the makers thinking!!!

 

[OnOff]

Hager's "Guide to Surge Protection Devices" here as a PDF, inc for TT systems:

http://www.hager.co.uk/products/energy-distribution/protection-devices/surge-protection/8028.htm