• Als Spam markieren
• Beitrag melden

• 
  Diese Gruppe Alles

• Archiv
• RSS-Feeds

• Kontakt
• Hilfe
• Impressum
• Datenschutz

Re: Warranty?

Cynic wrote:

> On Wed, 4 Nov 2009 20:21:59 -0000, "Ian" <idh@henden.co.uk> wrote:
>
> > ISTM that the only way that a cooker could sustain damage, being
> > installed in a place where a cooker of similar power requirement
> > has been installed previously, would be if it were subject to
> > excess voltage (and thus excess current). How could that happen?
> > Thank you for your comment.
>
> It could become dangerous to the user if it was wired incorrectly.
> Cookers are notorious for developing current leaks between the
> heating elements and their metal chassis, so simply omitting to
> connect the earth wire, or relying only on a flexible metal conduit
> to maintain the earth would create a potential timb-bomb.
>
> Some cookers have several different wiring options, allowing a
> low-current mains supply to be connected to feed clocks and lights
> on the cooker that by-passes the main cooker breaker.  If that
> option is not being used, the two supplies are usually bridged on
> the cooker's terminal block and the cooker fed from only the
> switched high-current supply.  Connecting both feeds but leaving
> the bridge in place means that the heating elements will be
> supplied from a permanently live low-current feed when the main
> cooker breaker is off.
>
> Yet other cookers have a 3-phase supply option.  Again, when a
> single phase is used, the 3 live phases are bridged.  Leave the
> bridge in place when wiring to a 3-phase supply and there will be
> fireworks as soon as the breaker is switched on!
>
> And then we have the case where the supply for the cooker is a 4
> wire 3 phase supply but the cooker is a single phase device.  2 of
> the 4 wires must be taped off, but which two?  Wiring colour codes
> have changed, and an ignorant or out-of-date fitter might end up
> connecting a single phase cooker across 2 lives of a 3-phase supply
> instead of between one of the lives and neutral.  And that would
> damage the cooker (though it may appear to work OK for as much as
> several weeks before an element burns out due to the excess voltage)
>
> If the grill element gets yellow-hot instead of red-hot it is a good
> indication that something is not right ...

We are talking domestic appliances here , very few are 2 phase plus
neutral  or 3 phase rated in the UK as its rare to have 3 phase in
domestic properties

Antworten