HomeRoast Digest


Topic: power question (6 msgs / 151 lines)
1) From: Phil Palmintere
I have a question to those of you who are more knowledgeable about such
things...
I'm using a popcorn popper rated at 120v 1250 watts, which, with Ohm's law,
indicates it should draw about 10.42 amps
I just picked up a Kill A Watt EZ at Costco.  
The Kill A Watt reports I have 120 volts (fluctuating from about 120.3 to
120.4), but once I turn on the popcorn popper, the Kill A Watt reports the
voltage at about 113.3 to 113.4 volts.
What, if anything, does this tell me for roasting? 
thanks
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

2) From: Yakster
The drop in voltage indicates that you have a voltage drop in your house
wiring due to the resistance of the wiring at that current level.
You may want to look for an outlet closer to your panel or one that's run
with higher gauge wire, this could be trial an error.  Also avoid long
extension cords if you want to maximize your voltage (but some folks use
extension cords to drop voltage to slow down their roasts).
This is pretty typical.  I plug my Behmor into the outlet that feeds my
washer/dryer in the garage and use a heavy gauge, short extension cord to
run it to my bench for roasting to minimize the voltage drop.
You may also see voltage dips during the day, especially on hot days due to
high usage on the power grid.
-Chris
On Wed, Sep 9, 2009 at 9:52 AM, Phil Palmintere 

3) From: Allon Stern
On Sep 9, 2009, at 12:52 PM, Phil Palmintere wrote:
<Snip>
It tells you that your branch circuit is sagging.http://www.psihq.com/iread/faqvolt.htmhttp://en.wikipedia.org/wiki/Voltage_drop
If you know what you're doing, make sure you have solid connections  
all around.
If you don't know what you're doing, consult with a licensed  
electrician.
Is it a 15A branch circuit? What else is on it?
Roasting with a popper or 120V 10A roaster is probably best done on a  
dedicated 20A circuit.
20A branch circuit is probably okay, but not as ideal.
The kill-a-watt may also be a bottleneck. I believe it is rated at  
15A. You can try measuring (with a different tool) with the kill-a- 
watt out of the loop. Or measure with the kill-a-watt in parallel to  
the load (assuming a duplex outlet)
-
allon
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

4) From: Jamie Dolan
<Snip>
<Snip>
drop.  I've done tests with much more expensive meters (True RMS
meters) and have seen similar voltage drop when using the I-Roast.
The length of the wire (how far this is from your panel) will directly
affect the amount of voltage drop.  It is possiable a connection is
less than perfect and that is causing increased voltage drop, but I
doubt it.  If there was, you would likely see a much larger drop.
If you plug this in at a outlet that is closer to your electrical
panel, you will see less voltage drop, but you will still see voltage
drop.  Even if you were checking the voltage right at your panel, you
will still see some voltage drop with a 10A draw anywhere in your
house.
For what it's worth, the Kill A watt, at least the one I have tends to
be quite accurate based on comparison to readings with a RMS clamp
meter.
Jamie
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

5) From: Yakster
BTW, Phil, I picked up that same Kill A Watt EZ the last time I went to
Costco.  I haven't noticed it being a bottleneck for my Behmor, I read
somewhere that someone used a Kill A Watt on a microwave that exceeded 15 A
and it caused the Kill A Watt to flash, but as long as your below 15 A, I
think you should be fine.  I also run a voltmeter in parallel so I can log
the min voltage while watching the Watts on the Kill a Watt and another
voltmeter displays the temperature from the temp probe (nice to have extra
voltmeters laying around).
Also, with your voltage dipping to 113, your current is going to creep up to
11 A to sustain the same 1250 W.  Did you measure the Watts with the Kill A
Watt too?
Often a voltage drop is not going to negatively affect a hot air popcorn
popper roast, in fact many people use long extension cords or variacs (with
or without split-wiring the heater circuit on the popper) to lower the
voltage and slow down the roast.  I used this trick when I was running hot
air poppers.  You may be trying to solve a problem that doesn't exist.  What
are your roast times looking like with the voltages you have?
-Chris
On Wed, Sep 9, 2009 at 10:13 AM, Allon Stern  wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

6) From: Bob Hazen
<Snip>
Not exactly. . . .  If it's a resistive heater, and it most likely is, then 
the current will drop as the voltage does.  The power in the heating element 
will also drop.  Only if the load is a constant power load like most 
computer power supplies, will the current increase in response to a voltage 
sag.
Bob
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20


HomeRoast Digest