Dodgy "Touch Dimmer" Table Lamps

[securespark]

I got a call today.

Got to the property.

"Can you check these lights for me? Everytime I switch them on, I'm getting a painful shock."

After testing them, the old lady reappeared.

"Have you touched them yet? Did you get the shock too?"

I explained that wasn't the best way of testing them...

Anyhow, here is a volt stick test on the casing:

And here is a voltage reading between the cpc of a well-earthed socket outlet and the appliance casing.

She had another (different) touch dimmer table lamp downstairs so out of interest I tested that too. No glowing volt stick & no voltage reading between earth & the casing.

 

[ban-all-sheds]

Did you check for correct polarity in the plug of the dodgy one?

 

[londonboy]

Did you check for correct polarity in the plug of the dodgy one?

Plug and socket!

 

[Adam_151]

Did you check for correct polarity in the plug of the dodgy one?

Chances are that the standard it should comply with would require it to be safe regardless of polarity

Sounds like badly designed imported rubbish to me simon, either it was designed with the casing able to give a perceiveable level of shock or its managed to fail to such a condition

... it would be interesting to see whats inside, if you offered to dispose of it for the homeowner?

 

[securespark]

Did you check for correct polarity in the plug of the dodgy one?

Yes. My Alphatek checks polarity as part of the EFLI test. It came out at 0.74 Ohms on a first floor socket outlet on a TN-S supply. The plug tops were both wired correctly too.

 

[ccam108]

Touch lamps work on capacitance which changes whenever you touch it. They will not work with the casing earthed. Check inside, one I had to fix recently had two capacitors in series with the wire to the casing - to ensure that if one fails there is still a safety measure. Maybe the cheap one only had the one which failed?

Colin C

 

[securespark]

Did not look inside. But the lamp was double insulated. Or at any rate, it was fed with flat twin flex.