On Sun, 1 Aug 2010 14:26:05 -0400, "Ed Pawlowski"
wrote:


"jeff_wisnia" wrote in message
m...
Ed Pawlowski wrote:


"Higgs Boson" wrote in message
...

Lately, one circuit on my box blows. It covers the microwave and
regular oven. I could
understand it blowing when another heat-using appliance, like toaster
oven or toaster runs at same time as microwave. But now it's blowing
all on its own.

Last time, today, only the micro was being used, to "reduce" a glass
dish of chicken drippings.

Can one circuit go bad all on its own? If so, why? And what should I
do about it.

Any info appreciated.


What is the "regular oven" you speak of? Like a toaster oven but larger?
It may have been marginal all along. What is the rating of the two
appliances? If the microwave motor is starting to go, it may be pulling
more amps that it normally does.

Also. what is the actual voltage coming in? In the summer with heavy
loads, the power company sometimes reduces the voltage a bit and that
increases the amps. If you live in an area of high tempertures that
may be going on some days as the AC load goes way up.

120 volts with a 1500 watt appliance = 12.5A reduce to 110 volts and you
get 13.6A Maximum safe load on a 20A breaker is 16A

Whaaaaat?

I seriously doubt that you are correct about that. I say the current at
110 volts would be closer to 11.5 amps. It's quite unlikely that an
appliance would be sophisticated enough to continue to consume the same
number of watts when the voltage is lowered.

I didn't make the laws of physics, but I usually follow them. Amps = volts
÷ watts. If one changes, another will. Are you saying the rated watts of
the heating element will change?
No, what he (and I) am saying is the resistance (effective load) will
stay the same, and if the voltage drops, the power consumed will also
drop. The only place that doesn't happen is with induction motors
where the back EMF drops, making them draw more current when the
voltage drops.