Scary stuff - didn't realise they could be dangerous:
BBC News - Richard Hammond tests dimmer switch danger

Scary stuff - didn't realise they could be dangerous:
BBC News - Richard Hammond tests dimmer switch danger

right, cause dimmers in houses and theatres are always catching fire?
this is just as bad as the Panorama Wireless scare....

Did you watch it?
What a load of scaremongering tosh.
Ben

But it's by the hamster - it has to be true?!?!
[NOTE - the above is a sarcastic comment]

Lol![]()


On that dimmer there showing the leads, some of them look like they failed PAT tests, surely not good advertising by the beeb to show using hardware that has failed pat!
As for that, as has been said another typical Beeb junk reporting situation!
Last edited by john; 8th May 2011 at 11:46 PM.
ok - so using triacs to control the power getting through does create harmonics, but not huge ones... a 60W light bulb at 10%'s harmonic distortion is nothing to worry about, the cable used for lighting is usually well over rated for the load. i don't see you running into your drama department and telling them not to use their dimmers? if it was dangerous we wouldn't be aloud to use them.
and it's the same effect from switch mode PSU i do believe, but we still run labs full of em (although they have power factor correction usually now)
just by co-incidence the zero 88 betapack 2 dimmers that are so often used in schools WILL and SHOULD fail a PAT test. they have a capacitor to meet CE regs and this means it will fail the PAT test. Not sure if the ones used in this was a zero 88 model but just a FYI. http://common.zero88.com/public/file...alIssue2_1.pdf page 8, bottom left, up a bit for reference.
Last edited by mjs_mjs; 9th May 2011 at 08:26 AM.

There was a mistake with that test. Hammond and the rest of the Top Gear team should have been in that shed.....

I watched this last night, and thought the whole point was not to show 'this is dangerous in your house' but to say 'this can be dangerous in very large buildings with lots of dimmers'. Obviously he's not saying, "quick, rip out your dimmers". He's merely showing an extreme case (the shed) as an example, and then quickly introduces the capacitor afterwards - the device that makes dimmers safe.
This isn't a whole load of scaremongering tosh at all. It's a program about engineering (and a program I enjoyed, even though i was slightly drunk) and it demonstrates how different obstacles are overcome.
Why are people always so skeptical on this website?
rsarg (10th May 2011)

Because we work in IT in Education?
Fail the standard test, yes. Dangerous, no. They may have a leakage to earth through the capacitor (that almost ALL dimmers NEED) but it will only "fail" if the tester doesn't know what he is doing.
American theater installations have their neutral conductors over rated by 50% due to the 1/3rd harmonics issue. Over here, it is all just a bit "looser".
Last edited by Andrew_C; 9th May 2011 at 08:58 AM.
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