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Topic: MORE WBI MODS???? (19 msgs / 305 lines)
1) From: Robert Holland
Being a little electrically challenged, what gauge wire did you change
out for the power cord there Alchemist John? My WB will push 120grams
pretty easily, but hey the more the merrier, till melt down!!
Bob
Dexter, Oregon
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2) From: AlChemist John
Can not be totally sure as it is not labeled but I would estimate 12-14 
gauge stranded copper (not guessing on the stranded copper).  If you really 
want to go for mods, try voltage boosting AND redesigning the roast chamber 
for more volume and maybe insulation.
Sometime around 20:10 3/1/2003, Robert Holland typed:
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BTW, Bob, are you looking at attending the Gathering at MM's in June?
--
John Nanci 
AlChemist at large
Zen Roasting and Blending by Gestalt
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3) From: R.N.Kyle
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the
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proportions."
I did some roasting outside today, I used a 80 ft. heavy duty extension =
cord, voltage at end (no load) 121.2
plugged in a 6 outlet surge protector, voltage ( no load) 119.8 I did =
not measure with load but the roast progressed as it did when I plugged =
it in straight. 
Ron Kyle
Anderson SC
rnkyle
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4) From: Mike McGinness
From: "Robert Holland" 
<Snip>
Simply the heavier the better, less resistance! 
PNW HomeRoast List Gathering Info' URLhttp://home.attbi.com/~mdmint/coffee/pnwhrg.htmMM;-) aka Kona Konnaisseur miKe mcKoffee
Frankenformer Rosto Roasting
Rocky grindin' - Miss Silvia brewin'
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5) From: 2D Softhome
Is there any website where some pictures and directions of the voltage
boosting design can be seen?
Thanks...
Paul
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6) From: Mike McGinness
Legal disclaimer: You didn't get this from me and I didn't post how-to on
the Web either!
PNW HomeRoast List Gathering Info' URLhttp://home.attbi.com/~mdmint/coffee/pnwhrg.htmMM;-) aka Kona Konnaisseur miKe mcKoffee
Frankenformer Rosto Roasting
Rocky grindin' - Miss Silvia brewin'

7) From: David Westebbe
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Is there any theoretical point which would be "sufficient"?  If we know the
maximum current draw and the length of the wire, can we estimate/calculate
what gauge would offer near-zero resistance?
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8) From: Dan Bollinger
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the
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According to my copy of "Practical Electrical Wiring", "Regardless of the
size of wire selected, it is impossible to prevent all voltage drop;
nevertheless, the drop must be held to nominal, practical proportions."
Voltage Drop = Amperes x Ohms (of the conductor)
2% voltage drop is considered the allowable limit
You must get into some simple, yet involved algebra to calculate 'circular
mils' and that sort of thing.  Luckily, the ampacity of wire sizes has been
determined.
14ga = 15amp
12ga = 20amp
10ga = 30amp
8ga = 45amp
Dan
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9) From: dewardh
Ron:
<Snip>
Maybe next time ? ? ?  That *is* how you'd determine voltage drop across the 
extension cord . . .
Deward
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10) From: David Westebbe
<Snip>
So it sounds like a 1500 watt popper could use 14 ga wire, and that anything
heavier would be overkill.
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11) From: Mike McGinness
From: "David Westebbe" 
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anything
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NOT NECESSARILY TRUE!!! Length is another major factor. The longer the cord
the larger the wire needs to be (higher gauge.) Get too long and voltage
drop will be too great regardless the cord size. Go to a hardware store like
Lowe's. They have charts for gauge need for amperage versus length. BTW, I
use a 25' 12ga construction grade cord to feed my roasting station. Can't
really speak to voltage drop though since FrankenFormer takes care of
that:-) OH, just realized you were speaking about WB1 supply cord... never
mind. But I'll post it anyway!
PNW HomeRoast List Gathering Info' URLhttp://home.attbi.com/~mdmint/coffee/pnwhrg.htmMM;-) aka Kona Konnaisseur miKe mcKoffee
FrankenFormer Rosto Roasting
Rocky grindin' - Miss Silvia brewin'
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12) From: Dan Bollinger
New homes require outlets to be 20A and use 12ga.  So the question is moot
unless you are considering an extension cord. Often, the weakest link is the
molded plug. They can get very warm. Lacking any sort of measuring
instruments you can tell if the wire size is too small by feeling the plug.
My Isomac has an 18ga. cord and it gets very warm when heating up a cold
boiler, but stays cool when it is maintaining temperature 24/7.  I plan on
changing it to a larger cord set. Dan
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anything
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13) From: David Westebbe
<Snip>
As a practical matter, what would you think of a 9 foot 14 ga cord for a
1500 watt popper?
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14) From: Mike McGinness
From: "David Westebbe" 
<Snip>
Not that I'm suggesting or saying you *should* use a 14ga power cord, but
that is in fact the gauge I used on the FrankenFormer, around 9ft at that!
:-)
PNW HomeRoast List Gathering Info' URLhttp://home.attbi.com/~mdmint/coffee/pnwhrg.htmMM;-) aka Kona Konnaisseur miKe mcKoffee
FrankenFormer Rosto Roasting
Rocky grindin' - Miss Silvia brewin'
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15) From: Rick Farris
Dan wrote:
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So far, so good, Dan, but it's a little more complicated than that, but it
can be less complicated!
The more complicated part is that obviously, if the 12ga (say) piece of wire
is 10 feet long, it will have half the resistance of a 20 foot piece.  So
what the figures above leave out is how long that theoretical piece of 12ga
wire is.  Whoops.
First, V = IR, as you said.  Also handy is that 2% of 120 volts is 2.4
volts.
Now, if the V is equal to 2.4 volts and the I is equal to (let's say) 20
amps, then the R (doing a quick rewrite to R = V/I), must be equal to 0.12
ohms.
Then if we only knew how many ohms/foot the various gauges of wire, were, we
could quickly calculate their voltage drop for any given length.  It might
turn out that for a length of 5 feet, 18 gauge would be fine, but for 15
feet, 14 gauge would be required.
The other, simpler thing would be to take your ohm meter to the store with
you, and measure the resistance of the various cords you're considering.  As
long as they were under 0.12 ohms, you'd be ok.  Unfortunately, the el
cheapo DVM that I have is not nearly accurate enough on its resistance scale
to measure fractional ohms.  A good Fluke with a low ohms scale would work.
I love ohms law.  It's about the only thing I know about electronics.
-- Rick
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16) From: 2D Softhome
Acknowledgement:  All Modifications done at own risk!!!
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17) From: AlChemist John
Sometime around 18:39 3/2/2003, David Westebbe typed:
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I just thought of sometime.  Everyone comments about the poppers (usually 
WBI in this case) being 1500W.  I recall during my various load and wiring 
checks that the system only pulled 6-8 A (been a while for the exact 
number), definitely not over 10A.  So, have I had MANY low amp WBI's or has 
"1500" just become a mantra?  Someone mind checking their own? (my 
voltmeter is at use at work)
<Snip>
--
John Nanci 
AlChemist at large
Zen Roasting and Blending by Gestalt
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18) From: Ken Mary
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I just measured the resistance at the heater leads which are isolated from
the fan. My two WBIs read 8.9 and 9.0 ohms, close enough to 1500 watts at
115 vac.
--
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19) From: Spencer W. Thomas
The resistance of the heater coil increases when it gets hot.  So when 
it's hot, it is drawing less current (and therefore using less power) 
than when you first turn it on.  The rating is based on the *maximum* 
current draw, because that's what you need to know to prevent circuit 
overload.
=Spencer
Ken Mary wrote:
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