5 Feb
2011
5 Feb
'11
11:10 a.m.
Many power tools sold in the US have no 3rd wire for grounding at
all, instead, a "double insulated" method of construction is used.
Samve over here. I guess it's safer than having a tool that should be
earthed if the earth wire has fallen off, but I am not sure I trust
double insulation as much as an earthed metal device.
What's curious is that such tools often employ the
"large blade =
neutra, small blade = line" polarized plugs.
All our plugs are polarised, and AFAIK all mains leads have different
colours of insulation on the live and neutral wires whether it matters or
not.
I wonder if the polarisated plugs on some power tools are due to the fct
that they only have single pole mains swtiches (wbich should be wired in
the live wire, of coruse [1]). I prefer doubel-pole switches, but that's
anothe rant...
[1] I once saw an SMPSU unit -- I think for a copy of the Apple ][ (but
certainly not a genuine Apple one)-- which was wired witha fuse in one
wire and a single pole switch in the other. OUCH!
-tony