Tingle from metal lamp = dangerous?
On Wed, 27 Apr 2005 20:16:20 UTC, Lars wrote:
I have an old Anglepoise lamp with painted metal arms and painted
metal lampshade (Anglepoise model 90). It has a two-core mains
lead. I am in the UK so this is all at 230-240 volts.
Today I touched the outside of the lampshade and got a sort of vey
mild tingle feeling which felt "odd". When I used a mains tester
screwdriver on the exposed metal (at the joint of the lampshade
and support arm) then it glowed as if the metal of the Anglepoise
lamp was live.
I unplugged the lamp and tested the resistence between the live
pin on the mains plug and some exposed metal on the lamp. I got
no resistence reading at all (i.e. it must have been a very high
resistence). I then tested the neutral pin in the same way and
got the same high resistence result.
QUESTION: Is my lamp safe to use and could I get a shock from it
in its present condition?
No. Yes.
QUESTION: If my lamp is unsafe then is there a repair I can do?
I would guess that the insulation is failing somewhere. Your test with
the meter wasn't high voltage and didn't show it up. You need proper
equipment to do that test.
I would guess that replacing all the wiring would probably do it. It
*might* be the lamp holder, but I'd change the wiring first. If you do
replace the lampholder, it's probably a special heat resistant one
(probably ceramic).
--
Bob Eager
begin a new life...dump Windows!
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