HomeRoast Digest


Topic: AlpenRost: AC current draw (6 msgs / 132 lines)
1) From: coffenut
Hey Folks,
I just recently acquired a 20-400amp digital clamp-on current probe and
decided to see just how much current this baby draws.  I built a test
pig-tail extension cord (1ft, 12ga) so I could clamp the probe around just
the hot lead of the line.
My setup was: [Alpenrost]--> [1ft 12ga pig-tail] --> [6ft 12ga ext cord] -->
[wall outlet 20amp]
Also:  Location was indoors at 72F using home-made blower to draw smoke
outdoors.
Here's what I measured, using the lowest scale on my probe (20amp), measured
about six inches from the Alp plug:
- Powered on and at rest - 0.05 amps
- After Start button pressed - initial 8.77 amps then settles down to 8.55
amps within first minute.
- After heater cycle begins (approx 2:10 minutes into roast) - Cycles
between 1.3 and 8.52 amps
- After Cool button pressed - 0.30 amps
- Dump beans cycle - 0.30 amps
I got virtually the same measurements across both of the 2 roasts I did
today.  When the heater cycling begins, my probe wasn't fast enough to
totally settle out between the few seconds of continuous cycle that occurs
throughout the roast.  It appears though, that the cycles vary in time
during the roast as there were points that my meter had more time to settle
during measurement.  I know this isn't very scientific, but it's more than I
used to know about the current draw of the Alp.
Coffenut  :^)
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

2) From: Gloria Hoover
Hi Coffeenut
That's interesting but can you please translate it into something that I a
non-electric person can understand.
Is that more than say a micro-wave, a toaster, oven? Now we have a Alp and have
noticed that at times the lights will flicker when the Alp "kicks" here. But
here on the west coast the power is not at the best currently (pun intended). No
the lights are not on the same circuit/breaker as the alp.
Gloriahttp://natures-emporium.com/Jewelry, jade, quartz, decor items, bookends
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

3) From: coffenut
Gloria,
Well, since you asked, and I have this handy little test rig, here's what I
measured a few minutes ago:
- Toastmaster toaster (on high) = 7.8amps
- Sharp Carousel II microwave (on high) = 11.7amps
So, the AlpenRost is somewhere in-between.  My lights don't flicker in the
kitchen when using the Alp, so maybe one of the our Electrical Engineer
types will step in to address that one.  I do have a similar situation when
my LaserJet printer cycles in my office and it causes my desk lamp to
flicker.
Coffenut  :^)
<Snip>
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

4) From: Gloria Hoover
Thanks, Coffeenut, that helps alot. And I was curious about this before you did
the test - glad you did it for us.
The lights that flicker are in the office where the PC is, the Alp is on the
stove top under the vent lol. When we have the living room lamp on it doesn't
flicker.
Again thanks for the information I enjoyed it.
Gloria--http://natures-emporium.com/Jewelry, jade, quartz, decor items, bookends
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

5) From: Keith Jones
Hey coffeenut,
Basically you can accomplish the same thing with a voltmeter and a little
math.   Your roaster is rated to draw a max 1020 watts, your average line
voltage is 115 - 120 volts.  To get the current your unit will draw, divide the
watts the unit is rated at by the line voltage-- 1020 divided by 115 equals 8.86
amps.  The current draw will be inversely proportional to the line voltage.  If
your line voltage is great the 115 VAC then the current will be a little less.
What you should really check is circuit load.  Plug your voltmeter into the same
circuit you have your Alps on, check the voltage without the Alps on, then turn
your Alps on, when the heater comes on, check the voltage, if there is a drop,
that means your loading the circuit.  A volt or two is not bad, but several
volts means you are overloading it and will shorten the life of the Alps. By the
way, sounds like yours is pretty good, looks like you are holding about 117 VAC
line voltage.
Some gee whizz info
Keith Jones
coffenut wrote:
<Snip>
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast

6) From: coffenut
Keith,
The meter I have will also measure AC/DC volts, so my line voltage is 122.8
VAC.  Then it drops to 118.5 VAC when you press the "Start" button and holds
there until the Alp begins to cycle.  When the Alp begins to cycle, the
voltage fluctuates between 118.5 and 121.6.  You're calculations were pretty
close to my actuals.
Coffenut  :^)
<Snip>
homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast


HomeRoast Digest