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Topic: strange roasting day (15 msgs / 443 lines)
1) From: L. Michael Fraley, MD
Hi all,
This morning, I found a batch of Guatemala FTO Quiche- Maya Ixil that I 
had roasted on March 3rd hiding on the shelf.  I had roasted this when 
I was experimenting with new profiles on my Hottop Programable.  I 
didn't like it, and I think that is why it was pushed to the back.  
Well, this morning when I found it, I thought, what the heck, let's 
give it a try.  It is fantastic now.  And the bloom, while brewing in 
my TV, was HUGE!  I thought it was odd to be so good after such a long 
rest.  Maybe I should give some of these profiles more of a chance with 
longer rests.
So, armed with this knowledge, and with my roasting diary, I set out to 
reproduce the results.  Unfortunately, the roaster did not want to 
cooperate.  Everything was going to plan, but when I ejected the beans 
(at a reading temp of 402F... just as last time, and just as I expected 
2nd crack at any second) only about 2/3 of the beans went into the 
cooling tray, and then the roaster died!  I mean totally died as if a 
circuit had blown.  As I am one who cares about the beans more than 
anything else, I quickly grabbed the cooling tray and dumped the beans 
into a colander.  I had a hair dryer nearby (that I use to blow chaff 
from my work surface from time to time) and it has a cool setting.  I 
stirred the beans and cooled with the hairdryer.  It was not until 
after all of this excitement that I noticed that I caused myself a 
nasty burn to my left thumb.  Huge blister.  Ouch!
So.. I let the roaster cool... took it apart (removed drum) and emptied 
the other beans (now ruined... I heard them 2nd cracking like crazy 
when I was cooling the salvaged ones.)  I reassembled the roaster, 
plugged it back in.. still nothing.  I tried other electrical items on 
this outlet to be sure I had not blown a circuit, and they worked fine. 
  I read on the Hottop site that it may be an internal fuse in the main 
board, or a "fusible link" that keeps the machine from overheating.  
Tomorrow, I will test these, and once I know which it is, get a new one 
from Hottop.  May get several, so as to have them on hand.  Do not like 
the impotent feeling of a disabled roaster!
My question:  If I were not yet (quite) to 2nd crack, why did the 
machine get so hot?  I have had it up to temps reading 410F without 
this problem.  Maybe because the ambient temp was so much higher today? 
  It was reading 85F in my garage.  I guess, to be complete, I should 
decide if it is the internal fuse, or the "fusible link" before I say 
it is from overheating.
Any thoughts?
At least the Guatemala this morning was good.
Michael
L. Michael Fraley, MD

2) From: Rich
Before prescribing a potential cure it is best to determine if it is an open circuit caused by the 
thermal overheat protection device or a fusible link which is an over current protection device.  Each 
will operate (open circuit) for a different set of initiating conditions.  Need to identify the problem
On Sat, 24 Mar 2007 18:37:13 -0400, L. Michael Fraley, MD wrote:
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3) From: L. Michael Fraley, MD
Hey Rich,
I am a little bit confused by what you are saying.  I thought the 
fusible link was a thermal overheat protection device, as apposed to an 
over current protection device (which I thought would be the fuse.)  
The Hottop website has this:  "The machine is protected from 
overheating by a length of special wire. This length of wire is a loop 
with both ends connected to the Main Circuit Board. The middle of the 
loop is attached to the backside of the rear wall of the roasting 
chamber. The wire acts as a thermal fuse. In the rare occurrence that 
the safety features of the machine fail and the roasting chamber 
overheats, the Fusible Link melts where it is attached to the roasting 
chamber and the machine turns off. If it has done its job the machine 
will not power up at all."
However, I do agree that you are right in saying that I need to decide 
which is the problem prior to finding a cure.
Michael
On Mar 24, 2007, at 6:59 PM, Rich wrote:
Before prescribing a potential cure it is best to determine if it is an 
open circuit caused by the
thermal overheat protection device or a fusible link which is an over 
current protection device.  Each
will operate (open circuit) for a different set of initiating 
conditions.  Need to identify the problem
On Sat, 24 Mar 2007 18:37:13 -0400, L. Michael Fraley, MD wrote:
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4) From: Rich
The link they are talking about is indeed a thermal shutdown device.  It is probably in the hot side of 
the 120vAC supply.  An open kills everything, just like pulling the plug.  Those types of protective 
device do just up and fail every so often.  The way it works is that the wire actually melts at a 
specified temperature.
If the machine also has an over current fuse installed that could also shut it down and is a different 
part.  I do not have a drawing so I do not know how it is wired but being equipped with an overcurrent 
protection is not an abnormal design.  That is why I said you have to find out which one is open 
circuit.  Not a problem if there is only one protective device.  You might be able to spot an open 
thermal link by looking at it where it connects to the drum, probably some small clip or clamp.  It will 
be protected by a high temp insulation but if it has melted open the insulation will be very flexible in 
the area of the open wire as compared to the rest of it.  They can also be brittle, be gentle.
On Sat, 24 Mar 2007 19:09:19 -0400, L. Michael Fraley, MD wrote:
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5) From: Barry Luterman
I have noticed that the new profiles require at least one or two days more 
rest than the same bean with the old profile did. Also on the new machine if 
the roast chamber hits 414 degrees it signals for 30 sec then dumps the 
beans and shuts down. Is that what happened?

6) From: L. Michael Fraley, MD
Thanks Rich.  I did find a diagram on their webpage.  If it is the 
fuse, those can be purchased anywhere.. like an automotive fuse.  If it 
is the other, I have to order it.
Michael
On Mar 24, 2007, at 7:27 PM, Rich wrote:
The link they are talking about is indeed a thermal shutdown device.  
It is probably in the hot side of
the 120vAC supply.  An open kills everything, just like pulling the 
plug.  Those types of protective
device do just up and fail every so often.  The way it works is that 
the wire actually melts at a
specified temperature.
If the machine also has an over current fuse installed that could also 
shut it down and is a different
part.  I do not have a drawing so I do not know how it is wired but 
being equipped with an overcurrent
protection is not an abnormal design.  That is why I said you have to 
find out which one is open
circuit.  Not a problem if there is only one protective device.  You 
might be able to spot an open
thermal link by looking at it where it connects to the drum, probably 
some small clip or clamp.  It will
be protected by a high temp insulation but if it has melted open the 
insulation will be very flexible in
the area of the open wire as compared to the rest of it.  They can also 
be brittle, be gentle.
On Sat, 24 Mar 2007 19:09:19 -0400, L. Michael Fraley, MD wrote:
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7) From: L. Michael Fraley, MD
Hi Barry,
No, that isn't how it happened.  I had actually just hit the eject 
button on my own, and the temp readout was showing 402F.  As the beans 
were falling out the chute, the entire machine just shut down as if 
somebody had pulled the plug.  It still will not come back on.
Michael
On Mar 24, 2007, at 8:13 PM, Barry Luterman wrote:
I have noticed that the new profiles require at least one or two days 
more rest than the same bean with the old profile did. Also on the new 
machine if the roast chamber hits 414 degrees it signals for 30 sec 
then dumps the beans and shuts down. Is that what happened?

8) From: Barry Luterman
sounds like a fuse

9) From: L. Michael Fraley, MD
I hope!  That would be easy!  But then, of course, that would beg the 
question.  Why did it blow?  But.. will cross that bridge as I come to 
it.
Michael
On Mar 24, 2007, at 10:24 PM, Barry Luterman wrote:
sounds like a fuse

10) From: Rich
It just looks like the automotive fuse, it is rated for 125 or 250 volts and a much higher current 
interrupting capability.  They can be tough to find unless you are in a larger city and have an electrical 
supply house that will talk to you.  Sometimes the places that sell the lighting fixtures have those fuses.  
I would bet on the fuse first and would want to have a spare on hand anyway.  Pull it out and hold it up 
to the light, you can see if the element is intact.  If you have a spare the one in service will never fail.  
Cheap insurance.  If you have a continuity checker you could check the fusible link.
Rich
On Sat, 24 Mar 2007 22:18:45 -0400, L. Michael Fraley, MD wrote:
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11) From: L. Michael Fraley, MD
Thanks Rich,
That is what I plan to do today.  I hope I can find the fuse (If that 
is what the problem is.)  Hottop's site said it was a automotive fuse 
and that it should be available anywhere.  Makes me wonder if they know 
what they are talking about.  Thanks for the help.
Michael
On Mar 25, 2007, at 12:15 AM, Rich wrote:
It just looks like the automotive fuse, it is rated for 125 or 250 
volts and a much higher current
interrupting capability.  They can be tough to find unless you are in a 
larger city and have an electrical
supply house that will talk to you.  Sometimes the places that sell the 
lighting fixtures have those fuses.
I would bet on the fuse first and would want to have a spare on hand 
anyway.  Pull it out and hold it up
to the light, you can see if the element is intact.  If you have a 
spare the one in service will never fail.
Cheap insurance.  If you have a continuity checker you could check the 
fusible link.
Rich
On Sat, 24 Mar 2007 22:18:45 -0400, L. Michael Fraley, MD wrote:
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12) From: Rich
Sounds like it is a fuse on the low voltage side of the unit.  That would shut it down dead if it opened.  
Any autoparts store will have the fuse or at worst a pack of an assortment.  Even Wal-Mart has them.  
If it is on the low voltage side thenit is a 32v rated fuse which is the auto part rated fuse.  You might 
be about to luck out on this one.
On Sun, 25 Mar 2007 11:04:32 -0400, L. Michael Fraley, MD wrote:
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13) From: L. Michael Fraley, MD
I hope you are right.  I will let you know after I investigate today.
Michael
On Mar 25, 2007, at 11:13 AM, Rich wrote:
Sounds like it is a fuse on the low voltage side of the unit.  That 
would shut it down dead if it opened.
Any autoparts store will have the fuse or at worst a pack of an 
assortment.  Even Wal-Mart has them.
If it is on the low voltage side thenit is a 32v rated fuse which is 
the auto part rated fuse.  You might
be about to luck out on this one.
On Sun, 25 Mar 2007 11:04:32 -0400, L. Michael Fraley, MD wrote:
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14) From: Rich
What is the amp rating of the fuse?  There is a small risk here but if it is 5 or 10 amps then I would be 
looking to also get a 7.5 or a 15 amp fuse.  It is a possibility (remote) that the factory recommended 
fuse is just under rated.
On Sun, 25 Mar 2007 11:30:50 -0400, L. Michael Fraley, MD wrote:
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15) From: L. Michael Fraley, MD
I haven't pulled it out yet.  I will let you know.
Michael
On Mar 25, 2007, at 11:43 AM, Rich wrote:
What is the amp rating of the fuse?  There is a small risk here but if 
it is 5 or 10 amps then I would be
looking to also get a 7.5 or a 15 amp fuse.  It is a possibility 
(remote) that the factory recommended
fuse is just under rated.
On Sun, 25 Mar 2007 11:30:50 -0400, L. Michael Fraley, MD wrote:
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