On Sep 20, 10:55*am, wrote:
On Sep 20, 1:17*am, wrote:

Resistive loads don't draw ten times their normal current on startup,
that's an induction motor starting stalled and even then 10x would be
pretty high.

What are you talking about? This resistive load is a tungsten or
nichrome or similar metal that with out a doubt changes resistance
depending on its temperature.

What he's talking about is that a resistive load in a coffee pot
doesn't change in resistance by anywhere near 10X over it's operating
range. * * If they did draw 10X, then the typical 1500W hair dryer
would draw 120amps when first turned on and you'd have tripped
breakers. * *A lot of this is probably being taken out of context from
the case of light bulbs, which do vary substantially in resistance
from cold to hot. * But in this case, cold is room temp or below and
hot is it glowing at thousands of degrees. *That doesn't happen in a
coffee pot, where the heating element is only going from 70 deg to
maybe 200 and the resistance change can be ignored.

Where does the 1500 watts come from????? (Or go to)?
The discussion is about a 'Coffee/tea WARMER'!
Probably less than 30 watts?

Or maybe we have changed over to discussing a coffee 'pot' or coffee
maker.
If so the 'inrush' current during the first half or full cycle after
first switching on from room temperature cold would
be ................ what?

Maybe half the resistance, for momentarily twice the operating
current?
Maybe quarter resistance, for momentarily four times the current?

Doubtful it would be anything like one tenth the normal operating
temperature resistance, even for that few milliseconds (1000/60 = 16.7
m/secs) = one cycle!

The temperature-resistance coefficient of typical (nichrome)
resistance wire (alpha) is say 0.00017.

In other words for a change in temperature from room at say 20C to red
hot at say 600C the amount of change of resistance would be about (600
- 20) x 0.00017 = 0.0986.

I think that means 9.86 percent lower resistance? Momentarily.