Re: Does any wall dimmer have overload protection?

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Tue, 8 Apr 2008 10:49:50 -0400, "Robert Green"
<ROBERT_GREEN1963@xxxxxxxxx> wrote in message
<VPydnedJd6PvFWbanZ2dnUVZ_saknZ2d@xxxxxxx>:

>I don't think there's any way to prevent plugging a vacuum cleaner into a
>dimmer unless you made the outlets and plugs incompatible.  An easy way to
>do that with a lamp outlet is to replace it with an ungrounded outlet and to
>make sure that the vacuum cleaner has a grounded plug.

Just so that we are clear, IMO this suggestion is _also_  a violation of the
US National Electrical Code (NEC) .

(But don't take your NEC advice from a geologist! ;-)

That way, you
>couldn't accidentally plug the three-pronged vacuum cleaner cord into the
>two pronged lamp outlet without a three-wire adapter plug.  That's pretty
>easy to do with plug-in lamp dimmer modules, because (IIRC) the X-10
>versions are all two pin devices.  That's not a complete solution, though,
>because more and more heavy duty appliances are double-insulated and do not
>use a three-pronged grounded plug.
>
>As Marc has noted, it's precisely this situation that makes dimmer
>controlled outlets "against code."  It's just too easy to make a mistake and
>plug in a motorized device, often with serious consequences.

Specifically supplying 'dimmed' power to a standard Edison AC power outlet
(eg "duplex" ; NEMA 5-15) is, in this geologist's opinion, a violation of the
National Electrical Code (NEC) 110-3(B) and 404.14(E) (and maybe others)

Lutron makes an specialized connector set (eg NTR-15-HFDU outlet and
RP-FDU-10 plug ) that has UL listing for dimming, but ABIK it is only UL-
listed for use with Lutron dimmers -- of course ! ;-)
www.lutron.com/pdfspecs/novatb.pdf These dimmers may very well also "make
smoke" when used with the inductive load presented by a vacuum-cleaner motor.

HTH ... Marc

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Marc_F_Hult
www.ECOntrol.org