"Tough Guy no. 1265" wrote in message
news
On Mon, 09 Nov 2015 19:04:56 -0000, Rod Speed
wrote:



"Tough Guy no. 1265" wrote in message
news
On Mon, 09 Nov 2015 18:36:32 -0000, Rod Speed
wrote:



"Tough Guy no. 1265" wrote in message
news On Mon, 09 Nov 2015 18:02:47 -0000, Dave Plowman (News)
wrote:

In article ,
Tough Guy no. 1265 wrote:
On Mon, 09 Nov 2015 13:48:44 -0000, Dave Plowman (News)
wrote:

In article ,
Tough Guy no. 1265 wrote:
Anyway, every time I've seen one of those yellow builders
transformers
for sale, it's referred to as isolating.

Of course it's isolating. That refers to the design of
transformer.

Hmmmm, isolating from the mains perhaps. I assumed isolating was
completely isolated, as in floating.

That's what it means. The output winding has no reference to the
input
one.

It does on one end in the case of an earthed builder's one.

Using an auto transformer

Oh is that what they're called, I call those Variacs. Very useful.

A Variac is a variable voltage transformer. And entirely different
device.

No, it's an auto transformer where you can move the tap. The coil is
in
the same configuration.

to give the 110v would work the tools - but could end
up with 240 on one leg of the output to ground if incorrectly
wired
up.

Anything can be dangerous if you wire it up wrong. Don't.

If you could guarantee everything was correctly wired and used
safely,
there'd be no need for additional safety precautions.

Safety precautions don't tolerate incorrect wiring.

Double insulated does.

Why do they call it double insulated?

Because it is, stupid.

It's just insulated. Eg. plastic chassis.

That is extra to the insulation on the wires, stupid.

Faults are usually the bare wire coming out of a connector,

And well designed system allows for all
faults, not just the most common ones.

And few wires come out of connectors
anymore with plugs molded on cables.

not the insulation on the wires decaying.

I said nothing about wires decaying.

That isn't the reason for double insulated devices.