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From: Dave Plowman (News) on 2 Jan 2010 08:15
In article <postings-27DDC5.17183701012010(a)news.bigpond.com>,
David <postings(a)REMOVE-TO-REPLYconfidential-counselling.com> wrote:
> > No it hasn't. Isolation transformers are still used for many safety
> > related reasons. But don't expect you to understand why. Obviously.

> I am one of those who rarely agree with Phil, but this time he is giving
> you the right info.

> From your post Dave it does seem you do not understand the reasons
> behind the use of isolation xformers when working on or testing gear.

Seems to me some expect the use of an isolation transformer to be some
form of magic bullet that removes all risks. It doesn't. But can reduce
the sort of risk caused by one side of a mains supply being grounded. If
you then ground one leg of the output of that transformer by any means you
are back to square one.
However, I can't think of any case where the use of an isolation
transformer *increases* any hazard.

--
*The early bird gets the worm, but the second mouse gets the cheese *

Dave Plowman dave(a)davenoise.co.uk London SW
To e-mail, change noise into sound.
From: sparky on 2 Jan 2010 08:58
On Jan 2, 8:15 am, "Dave Plowman (News)" <d...(a)davenoise.co.uk> wrote:
> In article <postings-27DDC5.17183701012...(a)news.bigpond.com>,
>    David <posti...(a)REMOVE-TO-REPLYconfidential-counselling.com> wrote:
>
> > > No it hasn't. Isolation transformers are still used for many safety
> > > related reasons. But don't expect you to understand why. Obviously.
> > I am one of those who rarely agree with Phil, but this time he is giving
> > you the right info.
> > From your post Dave it does seem you do not understand the reasons
> > behind the use of isolation xformers when working on or testing gear.
>
> Seems to me some expect the use of an isolation transformer to be some
> form of magic bullet that removes all risks. It doesn't. But can reduce
> the sort of risk caused by one side of a mains supply being grounded. If
> you then ground one leg of the output of that transformer by any means you
> are back to square one.
>  However, I can't think of any case where the use of an isolation
> transformer *increases* any hazard.


Quite correct.
The isolation transformer is a great tool for the workbench if a
person knows how to utilize it. That appears to be the problem with
some posters here. They have either had no instructions about the use
of the isolation transformer on the service bench or they just ignore
any instruction they have had.
From: Ron on 2 Jan 2010 10:08
On 02/01/2010 13:58, sparky wrote:
> On Jan 2, 8:15 am, "Dave Plowman (News)"<d...(a)davenoise.co.uk> wrote:
>> In article<postings-27DDC5.17183701012...(a)news.bigpond.com>,
>> David<posti...(a)REMOVE-TO-REPLYconfidential-counselling.com> wrote:
>>
>>>> No it hasn't. Isolation transformers are still used for many safety
>>>> related reasons. But don't expect you to understand why. Obviously.
>>> I am one of those who rarely agree with Phil, but this time he is giving
>>> you the right info.
>>> From your post Dave it does seem you do not understand the reasons
>>> behind the use of isolation xformers when working on or testing gear.
>>
>> Seems to me some expect the use of an isolation transformer to be some
>> form of magic bullet that removes all risks. It doesn't. But can reduce
>> the sort of risk caused by one side of a mains supply being grounded. If
>> you then ground one leg of the output of that transformer by any means you
>> are back to square one.
>> However, I can't think of any case where the use of an isolation
>> transformer *increases* any hazard.
>
>
> Quite correct.
> The isolation transformer is a great tool for the workbench if a
> person knows how to utilize it. That appears to be the problem with
> some posters here. They have either had no instructions about the use
> of the isolation transformer on the service bench or they just ignore
> any instruction they have had.

The golden rule when working on any kind of live gear, isolation tranny
or not, is to keep one hand in your pocket (but not too close to the
'spheres'

Ron
From: David on 2 Jan 2010 19:19
In article <50d3511cf4dave(a)davenoise.co.uk>,
"Dave Plowman (News)" <dave(a)davenoise.co.uk> wrote:

> In article <postings-27DDC5.17183701012010(a)news.bigpond.com>,
> David <postings(a)REMOVE-TO-REPLYconfidential-counselling.com> wrote:
> > > No it hasn't. Isolation transformers are still used for many safety
> > > related reasons. But don't expect you to understand why. Obviously.
>
> > I am one of those who rarely agree with Phil, but this time he is giving
> > you the right info.
>
> > From your post Dave it does seem you do not understand the reasons
> > behind the use of isolation xformers when working on or testing gear.
>
> Seems to me some expect the use of an isolation transformer to be some
> form of magic bullet that removes all risks. It doesn't. But can reduce
> the sort of risk caused by one side of a mains supply being grounded. If
> you then ground one leg of the output of that transformer by any means you
> are back to square one.
> However, I can't think of any case where the use of an isolation
> transformer *increases* any hazard.

Well, I sure can. When they listen to someones advice that it is OK to
touch either side of the output of the xformer. As Phil pointed out if
there is a problem that could be lethal

David
From: David Nebenzahl on 2 Jan 2010 19:33
On 1/2/2010 4:19 PM David spake thus:

> In article <50d3511cf4dave(a)davenoise.co.uk>,
> "Dave Plowman (News)" <dave(a)davenoise.co.uk> wrote:
>
>> However, I can't think of any case where the use of an isolation
>> transformer *increases* any hazard.
>
> Well, I sure can. When they listen to someones advice that it is OK to
> touch either side of the output of the xformer. As Phil pointed out if
> there is a problem that could be lethal

That is in no way a fault of the isolation transformer. Might as well
blame power lines because some doofus, somewhere told someone that it's
OK to touch one side of the line.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"
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