[Homeroast] Electrical question on coffee brewers

raymanowen at gmail.com raymanowen at gmail.com
Thu Oct 7 03:48:09 CDT 2010


The new power substation is being installed to solve some other problem.
They're not free, and it probably won't solve your problem.

Have you made note of the times of day during which the power at the outlet
is high and low? Or the total resistance of the wires and electrical devices
between the pole transformer and your coffee pot? The latter will not be
affected by a substation, if you even lived next door to Hoover Dam, and you
can't measure it directly.

Of course, the line resistance between the pole transformer and your roof
jack is not your responsibility. If it's excessive, Reddi Kilowatt should
make it good.

Simple to determine the outside line resistance, exclusive of your circuit
breaker and wiring devices:

   1. With your coffee pot unplugged and no other heavy load on that
   circuit, measure the voltage at a test receptacle on a different unloaded
   circuit in the house-
   2. Record the volts at the test receptacle (V1)
   3. Fill pot with dummy load of water, turn it On, plug it in and record
   (V2} at the test receptacle.
   4. Calculate the voltage difference (V1 - V2) caused by the coffee pot's
   current draw-
   5. Divide (V1 - V2) by the nameplate current draw of the coffee pot. For
   reasons stated by miKe, it won't be precisely accurate but you'll know the
   magnitude of the line resistance. ex: 1225w/117.5v = 10.4 ampere

For example, suppose you see a 119v - 116v = 3-volt change (rise or fall)
between the coffee pot connected and disconnected, measuring at the test
receptacle, and the current is stated to be 10 amperes, but you question
that number and the fraud Kill-a-Watt that gives derived numbers as if they
were basic quantities. Good attitude.

Besides, the 3-volt change on the 117.5-volt median is 2.5% change- Not
interesting to Reddy Kilowatt. They might offer some left-over office party
cheese to go with your whine.

Cheers, Mabuhay, Iechyd da -RayO, aka Opa!

Numbers at night is not good- likely to be misteaks


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