|
Posted by Eric9822 on January 17, 2007, 10:15 pm
trainfan1 wrote:
> joshers17@hotmail.com wrote:
>
> > Actually wouldnt a reading of 0 ohms indicate a short? I thought the
> > way a heating element worked was due to resistance to current flow.
> > You definately dont want infinite resistance, as that indicates and
> > open...but if i remember correctly a good heating element on my dryer,
> > for example runs a few ohms resistance.
> >
> > Please correct and cite me if im wrong...I could be..
> >
> > Josh
>
> I'm quite sure "a few ohms resistance" is pretty damn near "close to
> zero ohms".
>
> Sounds like you guys are in agreement here...
>
> Rob
There is a very large difference between zero ohms and a few ohms,
zero ohms would draw an infinite amount of current. The resistance
should very low, i.e. around 12 ohms for a 3.8KW element supplied by
240V. I suggest you measure the resistance of the heating element and
then calculate the expected amp draw at the applied voltage. The
formula is voltage/divided by resistance or I=V/R (I is current). Then
find the KW by multiplying the voltage, the current, and the power
factor (I would assume .8) and then divide by 1000 or KW=V*I*.8/1000.
What you calculate should match the KW rating of the element. If it
does not there is a problem. I agree that heating elements usually
either work or they don't. I also agree with a previous poster that it
is possible to test on a bench by very briefly connecting a 220V or
110V source to test the element. The watchout is that the element will
heat up VERY rapidly and can cause an injury, a fire, or burn out the
element since it will not be immersed in water.
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap