Two comments:

If it were to matter -- presumably for safety's sake -- then
the transformer should be manufactured with a polarized
plug.  So, assuming that the manufacturer plays by the
rules, if it doesn't have a polarized plug, you should be okay
either way.

As far as what's going on under the hood:

Since the transformers of this type that I've seen have no
grounded cases, no 'chassis' ground, no power switches
and no fuses (it's better practice to put switches and
fuses on the 'hot' side), there is no reason that it *could*
matter.

Lastly, I've always plugged these things in based on
convenience and the goal of not blocking other outlets
on a power strip, and have never had a problem.

Good luck.  (zap...)


Mark Rode <[log in to unmask]> wrote:

> 120 >> 12 volt transformers for PC devices such as hubs, speakers and
> modems never have polarized plugs.
> However I have always made sure that the transformers are plugged in at the
> correct direction relative to the printing on the device so as to put the
> hot lead on the right. This is not always easy to arrange without loosing
> some outlets on a surge protector or UPS.
>
> Because the transformers never have polarized plugs I am not sure that this
> is in fact necessary ?
> Is this a good idea or does it matter ?

                  Visit our website regularly for FAQs,
               articles, how-to's, tech tips and much more
                  http://nospin.com - http://nospin.org