Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Do thermal fuses fail from old age?

'Course the minuscule size of today's electronics and my aging
eyesight makes it a no-win game for me to try and do much

fixing of that kind of stuff those days.


I just bought an illuminated head-mount magnifier from Harbor Freight for
$5. It's surprisingly good. The optics have little distortion and no
chromatic aberration. There are four magnifications, but the lights "focus"
at only the lowest magnification.


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On Fri, 23 Mar 2012 12:48:47 -0700, "William Sommerwerck"
wrote:

'Course the minuscule size of today's electronics and my aging
eyesight makes it a no-win game for me to try and do much

fixing of that kind of stuff those days.


I just bought an illuminated head-mount magnifier from Harbor Freight for
$5. It's surprisingly good. The optics have little distortion and no
chromatic aberration. There are four magnifications, but the lights "focus"
at only the lowest magnification.


I don't really like the plastic head mounted magnifiers. I'm
constantly going from whatever I'm working on, to picking up tools,
soldering iron, parts, probes, etc, on the bench. I have to keep
raising and lowering the magnifier in order to switch. With an LCD
screen, everything is roughly the same distance away, so no raising or
lowering.

If I were to buy a head mounted magnifier, it will probably be a
surgical loupe.
https://www.google.com/search?q=surgical+loupe&tbm=isch
Lots of styles and types to choose from, all seriously expensive. I've
played with some and am rather impressed. If I can keep the working
distance constant, it's as good or better than my USB camera
microscope. Mounted on eyeglasses, they are a bit heavy, but headband
mounts are available.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Do thermal fuses fail from old age?

William Sommerwerck wrote:

'Course the minuscule size of today's electronics and my aging
eyesight makes it a no-win game for me to try and do much

fixing of that kind of stuff those days.


I just bought an illuminated head-mount magnifier from Harbor Freight for
$5. It's surprisingly good. The optics have little distortion and no
chromatic aberration. There are four magnifications, but the lights "focus"
at only the lowest magnification.


Those things and drugstore reading glasses are great if you happen to
have just the right interpupillary distance. I buy lab glasses from
Zenni Optical for about $35 a pair--+0.75 diopter for reading, +2.5 for
close work, coated, good frames, just the right interpupillary distance
to avoid eyestrain. Highly recommended.

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
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"Jeff Liebermann = Nut Case ****wit "

The coffee distillery is double insulated, which means it doesn't need
a ground pin on the power plug. Since a fault can affect either side
of the power line in such a symmertical arrangement, two fuses are
required.


** Horse manure.


Yep.


** Glad you agree- ****wit.


One fuse is sufficient to break the circuit in case of current overload.


http://www.freewebs.com/valvewizard/fuses.html
Some appliances use two fuses, one for live and one for
neutral. While there is some argument against using a
neutral fuse, there is no law against it (in the UK anyway).
You can buy IEC inlet sockets with built-in fuse holders,
which greatly simplifies construction.



** Utterly irrelevant crap.


http://www.appliance411.com/faq/dryerheat.shtml
There are 2 fuses or breakers for the dryer, both must
be good in order for the dryer to function properly.


** That schem shows TWO PHASE power being used.

You ****ing tenth wit.



Thermal fuses act on temperature, not current at all.


True.


** Glad you agree - ****head.


The max current rating given by makers is based on self heating to ensure
the fuse stays within temp rating tolerance.


The max current rating is the maximum current at which it will operate
safely without self-heating and blowing the fuse.



** There is only a few degrees of self heating at the rated current.

So to melt the material inside takes at least 5 times that current.


I found out the
hard way that it's much like the rating on a typical wire fuse. If
you run a 5A fuse, at 5 amps at room temperature, it will eventually
blow.



** Wire fuses run very hot at rated current, the wire inside may bend or
even glow in the dark - ie nothing like thermal fuses.

Same with a thermal fuse.


** Blatant LIE.

If you run it near it's rated
maximum current (usually 5A, 15A, or 30A), it will eventually get warm
enough to melt the wax and trip the fuse.


** MASSIVE BULL**** !!!!!!!!!!


With a short circuit across
the power line, the self-heating will blow the thermal fuse almost
instantly.


** Nope - it will trip the supply breaker.

With a 10 times or more overload, breakers trip in a few milliseconds.

You stupid asshole.


.... Phil


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N_Cook wrote:

Michael A. Terrell wrote in message
m...

N_Cook wrote:

Perhaps the voltage rating was lower than the required use, ie in fused
state not rated for the service voltage across the broken section so

someone
thought, I know , we'll put 2 in series ;-)



Which would do nothing, if they couldnn't handle the voltage.

Have you ever looked at the wiring in a furnace? They use multple
thermal shutdowns, for liability in the US.


so you have no visual sense for emoticons



I did too many fire restoration jobs after a pair of switches failed
and people died. I see no humor in people dying from failed and jury
rigged repairs. Laugh all you want. It fits you.


--
You can't have a sense of humor, if you have no sense.


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The Daring Dufas wrote:

P.S. They often get mad when someone like me is teasing them. o_O



Some just consider the source, and ignore you.


--
You can't have a sense of humor, if you have no sense.
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Default Do thermal fuses fail from old age?

On Thu, 22 Mar 2012 10:12:07 -0400, Phil Hobbs
wrote:

Nasty cheap Chinese thermal fuses-higher rate of failure to open in a
real overtemp condition-using two in series may keep your house from
burning down, if they don't both fail the same way.


Maybe. Such guesswork would be greatly reduced if the original poster
would kindly provide the Braun model number.
https://www.google.com/search?&q=braun+coffee+maker&tbm=isch

If the coffee maker is of the drip type automatic variety, then there
are two heaters. The upper heater, that heats the water before it
goes through the coffee filter, and the warmer at the base, that keeps
the pot of coffee warm. Such a derrangement requires two thermal
fuses, one for each heater.

Incidentally, I had a really old Mr Coffee maker overheat and melt the
plastic case. The thermal fuse never blew. The consensus was that
water somehow invaded the Microtemp thermal fuse, and rusted
everything in place.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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On 3/23/2012 5:02 PM, Michael A. Terrell wrote:

N_Cook wrote:

Michael A. wrote in message
m...

N_Cook wrote:

Perhaps the voltage rating was lower than the required use, ie in fused
state not rated for the service voltage across the broken section so

someone
thought, I know , we'll put 2 in series ;-)


Which would do nothing, if they couldnn't handle the voltage.

Have you ever looked at the wiring in a furnace? They use multple
thermal shutdowns, for liability in the US.


so you have no visual sense for emoticons



I did too many fire restoration jobs after a pair of switches failed
and people died. I see no humor in people dying from failed and jury
rigged repairs. Laugh all you want. It fits you.


I repaired a furnace for one of my favorite customers, a little old lady
about 90 who had her children and grandchildren staying with her
and she had no heat. I found that water flooding the basement had
shorted out the control board for her furnace but some moron had
bypassed the roll-out safety switch on the furnace because another
safety wasn't working. Needless to say, I had to replace a whole section
of the wiring harness because the flames blew back from the burners
destroying the wiring. It was a lucky break that the burned wiring
shorted out killing the furnace or I fear the house would have caught
fire with all those folks in there. I wish I could get my hands around
the neck of the asshole who decided it was a good idea to bypass the
safety switches on that furnace. o_O

TDD


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The Daring Dufas wrote:

On 3/23/2012 5:02 PM, Michael A. Terrell wrote:

N_Cook wrote:

Michael A. wrote in message
m...

N_Cook wrote:

Perhaps the voltage rating was lower than the required use, ie in fused
state not rated for the service voltage across the broken section so
someone
thought, I know , we'll put 2 in series ;-)


Which would do nothing, if they couldnn't handle the voltage.

Have you ever looked at the wiring in a furnace? They use multple
thermal shutdowns, for liability in the US.

so you have no visual sense for emoticons



I did too many fire restoration jobs after a pair of switches failed
and people died. I see no humor in people dying from failed and jury
rigged repairs. Laugh all you want. It fits you.


I repaired a furnace for one of my favorite customers, a little old lady
about 90 who had her children and grandchildren staying with her
and she had no heat. I found that water flooding the basement had
shorted out the control board for her furnace but some moron had
bypassed the roll-out safety switch on the furnace because another
safety wasn't working. Needless to say, I had to replace a whole section
of the wiring harness because the flames blew back from the burners
destroying the wiring. It was a lucky break that the burned wiring
shorted out killing the furnace or I fear the house would have caught
fire with all those folks in there. I wish I could get my hands around
the neck of the asshole who decided it was a good idea to bypass the
safety switches on that furnace. o_O



I used to subcontract electronic repair for a fire restoration
company. Most of their jobs were to repair the buildings so the heirs
could sell them. They wanted nothing to do with the place their parent
or parents died. More than one death was caused by an incompetent
repair. A thermal overload failed? No big deal: "he terminals on the
wires will push together, so all I need is some tape and I'll charge the
suckers a couple hundred dollars."

TDD



--
You can't have a sense of humor, if you have no sense.
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Jeff Liebermann wrote in
:

On Thu, 22 Mar 2012 19:30:18 -0400, jeff_wisnia
wrote:

'Course the current miniscule size of todays electronics and my aging
eyesight makes it a no-win game for me to try and do much fixing of that
kind of stuff those days.


I use a microscope camera:
http://www.ebay.com/itm/260969643003 $30
I have it plugged into a junk computah and LCD display. The original
plan was to attach it to a wrist strap, to make it easier for me to
see what I'm doing while soldering, but that didn't work. So, I now
use it on a plastic camera tripod, which works well. Saving the JPG's
has been handy for recording my work.

Unfortunately, I still have to wear my reading glasses in order to see
the LCD display. You can also use some cell phone cameras as a
microscope, if they have auto-focus (iPhone 3GS, most Droids, etc).




I have reading glasses(2.75X) and also have a separate binocular magnifier
of 2.5X.

you can buy "clip-on" binocular magnifiers for pretty low cost on Ebay,I
got mine for $5 USD,plus shipping. they either clip on your regular
glasses,or clip on their own eyeglass frame. They are easier to see around
than the hobby binoc flip-up magnifiers,when you don't need close up
vision,you don't have to move them out of the way.

--
Jim Yanik
jyanik
at
localnet
dot com


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On 3/23/2012 7:06 PM, Michael A. Terrell wrote:

The Daring Dufas wrote:

On 3/23/2012 5:02 PM, Michael A. Terrell wrote:

N_Cook wrote:

Michael A. wrote in message
m...

N_Cook wrote:

Perhaps the voltage rating was lower than the required use, ie in fused
state not rated for the service voltage across the broken section so
someone
thought, I know , we'll put 2 in series ;-)


Which would do nothing, if they couldnn't handle the voltage.

Have you ever looked at the wiring in a furnace? They use multple
thermal shutdowns, for liability in the US.

so you have no visual sense for emoticons


I did too many fire restoration jobs after a pair of switches failed
and people died. I see no humor in people dying from failed and jury
rigged repairs. Laugh all you want. It fits you.


I repaired a furnace for one of my favorite customers, a little old lady
about 90 who had her children and grandchildren staying with her
and she had no heat. I found that water flooding the basement had
shorted out the control board for her furnace but some moron had
bypassed the roll-out safety switch on the furnace because another
safety wasn't working. Needless to say, I had to replace a whole section
of the wiring harness because the flames blew back from the burners
destroying the wiring. It was a lucky break that the burned wiring
shorted out killing the furnace or I fear the house would have caught
fire with all those folks in there. I wish I could get my hands around
the neck of the asshole who decided it was a good idea to bypass the
safety switches on that furnace. o_O



I used to subcontract electronic repair for a fire restoration
company. Most of their jobs were to repair the buildings so the heirs
could sell them. They wanted nothing to do with the place their parent
or parents died. More than one death was caused by an incompetent
repair. A thermal overload failed? No big deal: "he terminals on the
wires will push together, so all I need is some tape and I'll charge the
suckers a couple hundred dollars."


That's basically what the idiot did and I come across that sort of thing
all the time across the many fields I work in. My friend GB
who owned the mechanical company I often helped him with was very
much like me in that we couldn't live with ourselves if we were to
cheat folks. GB passed away last fall so I'm not doing much in the
way of residential HVAC work but there is enough commercial work to
keep me occupied along with all the other stuff. I see incompetent
work and dangerous shortcuts quite often and I make sure the customer
is aware of how dangerous that sort of thing is and I would be
absolutely devastated if someone were harmed because of something I
did, especially if it was a child. If you've ever come across the
website "There, I Fixed It" and seen some of the insane shortcuts and
godawful dangerous things people do you may laugh like I do because I've
actually seen people do the same crazy things. o_O

TDD
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The Daring Dufas wrote:

On 3/23/2012 7:06 PM, Michael A. Terrell wrote:

The Daring Dufas wrote:

I repaired a furnace for one of my favorite customers, a little old lady
about 90 who had her children and grandchildren staying with her
and she had no heat. I found that water flooding the basement had
shorted out the control board for her furnace but some moron had
bypassed the roll-out safety switch on the furnace because another
safety wasn't working. Needless to say, I had to replace a whole section
of the wiring harness because the flames blew back from the burners
destroying the wiring. It was a lucky break that the burned wiring
shorted out killing the furnace or I fear the house would have caught
fire with all those folks in there. I wish I could get my hands around
the neck of the asshole who decided it was a good idea to bypass the
safety switches on that furnace. o_O



I used to subcontract electronic repair for a fire restoration
company. Most of their jobs were to repair the buildings so the heirs
could sell them. They wanted nothing to do with the place their parent
or parents died. More than one death was caused by an incompetent
repair. A thermal overload failed? No big deal: "he terminals on the
wires will push together, so all I need is some tape and I'll charge the
suckers a couple hundred dollars."


That's basically what the idiot did and I come across that sort of thing
all the time across the many fields I work in. My friend GB
who owned the mechanical company I often helped him with was very
much like me in that we couldn't live with ourselves if we were to
cheat folks. GB passed away last fall so I'm not doing much in the
way of residential HVAC work but there is enough commercial work to
keep me occupied along with all the other stuff. I see incompetent
work and dangerous shortcuts quite often and I make sure the customer
is aware of how dangerous that sort of thing is and I would be
absolutely devastated if someone were harmed because of something I
did, especially if it was a child. If you've ever come across the
website "There, I Fixed It" and seen some of the insane shortcuts and
godawful dangerous things people do you may laugh like I do because I've
actually seen people do the same crazy things. o_O



Ever looked at "White Trash Repairs"? Some dangerous idiots on that
site like the guy who blows up microwave ovens, or the one making
fireworks in his house.


The losers who do some electrical work should have to live in the
houses they wire.

I installed the computer networking, fire alarms and TV antenna
systems at a new college campus years ago. The HVAC crew was the
biggest idiot's I've ever had the misfortune to work around. The
blueprints showed where every air handler was supposed to go, so that
the ducting would have plenty of clearance. They not only set them in
the wrong places, one was backwards, with their wiring hanging from the
20 foot ceilings. the gofer for the general contractor kept running
around pulling the fire boxes while I was trying to test the prewire,
until I caught him in the act. I followed him to his bosses office and
read him the riot act. Then I promised to kick his sorry ass all the
way across the campus if anyone pulled another box. he told me I
couldn't do it, but his boss said that he would be a fool to try, and
find out for sure.

When it was time for the state inspector & his punch list he said the
system failed, because the glass break rods were missing. I told him
they would be installed, but only after the building was accepted and
that the weren't installed due to over 100 attempts to cause a false
alarm.

That was the last time I did any sub work for that electrical
contractor.

--
You can't have a sense of humor, if you have no sense.
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On 3/23/2012 9:36 PM, Michael A. Terrell wrote:

The Daring Dufas wrote:

On 3/23/2012 7:06 PM, Michael A. Terrell wrote:

The Daring Dufas wrote:

I repaired a furnace for one of my favorite customers, a little old lady
about 90 who had her children and grandchildren staying with her
and she had no heat. I found that water flooding the basement had
shorted out the control board for her furnace but some moron had
bypassed the roll-out safety switch on the furnace because another
safety wasn't working. Needless to say, I had to replace a whole section
of the wiring harness because the flames blew back from the burners
destroying the wiring. It was a lucky break that the burned wiring
shorted out killing the furnace or I fear the house would have caught
fire with all those folks in there. I wish I could get my hands around
the neck of the asshole who decided it was a good idea to bypass the
safety switches on that furnace. o_O


I used to subcontract electronic repair for a fire restoration
company. Most of their jobs were to repair the buildings so the heirs
could sell them. They wanted nothing to do with the place their parent
or parents died. More than one death was caused by an incompetent
repair. A thermal overload failed? No big deal: "he terminals on the
wires will push together, so all I need is some tape and I'll charge the
suckers a couple hundred dollars."


That's basically what the idiot did and I come across that sort of thing
all the time across the many fields I work in. My friend GB
who owned the mechanical company I often helped him with was very
much like me in that we couldn't live with ourselves if we were to
cheat folks. GB passed away last fall so I'm not doing much in the
way of residential HVAC work but there is enough commercial work to
keep me occupied along with all the other stuff. I see incompetent
work and dangerous shortcuts quite often and I make sure the customer
is aware of how dangerous that sort of thing is and I would be
absolutely devastated if someone were harmed because of something I
did, especially if it was a child. If you've ever come across the
website "There, I Fixed It" and seen some of the insane shortcuts and
godawful dangerous things people do you may laugh like I do because I've
actually seen people do the same crazy things. o_O



Ever looked at "White Trash Repairs"? Some dangerous idiots on that
site like the guy who blows up microwave ovens, or the one making
fireworks in his house.


The losers who do some electrical work should have to live in the
houses they wire.

I installed the computer networking, fire alarms and TV antenna
systems at a new college campus years ago. The HVAC crew was the
biggest idiot's I've ever had the misfortune to work around. The
blueprints showed where every air handler was supposed to go, so that
the ducting would have plenty of clearance. They not only set them in
the wrong places, one was backwards, with their wiring hanging from the
20 foot ceilings. the gofer for the general contractor kept running
around pulling the fire boxes while I was trying to test the prewire,
until I caught him in the act. I followed him to his bosses office and
read him the riot act. Then I promised to kick his sorry ass all the
way across the campus if anyone pulled another box. he told me I
couldn't do it, but his boss said that he would be a fool to try, and
find out for sure.

When it was time for the state inspector& his punch list he said the
system failed, because the glass break rods were missing. I told him
they would be installed, but only after the building was accepted and
that the weren't installed due to over 100 attempts to cause a false
alarm.

That was the last time I did any sub work for that electrical
contractor.


I will no longer tolerate sabotage or someone fooling around with my
work on a construction project. I've decided the best thing to do is
call the police and file a report along with a dollar value of the
damage based on my highest hourly rate. I will definitely have one of
perpetrators jailed on felony charges if the dollar amount is enough.
The police reports come in handy for a lawsuit against a contractor
with a "Screw You!" attitude.

I was doing some control work with an engineer friend of mine I had met
when we worked on a construction project for The Star Wars "SDI" program
back in the 80's and we were installing a large HVAC control system for
a new school in the 90's and on that job, one of the young don't give a
damn electricians decided to cut and pull our control wire out of a roof
penetration conduit so he could use it. The conduit was 40' in the air
and luckily one of the other electricians told us before the ceiling was
installed. The kid's excuse for ripping out our wire was that it was in
his way and when asked why he didn't tell us so we could handle the
problem was the fact that we weren't there that day. I don't know if
personal civilian Tasers were available at the time but I would have
liked to have owned one. ^_^

P.S. Some day I'll have to tell you of my adventures the with the Halon
fire suppression system I installed in Mission Control at the missile
range. o_O

TDD
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Default Do thermal fuses fail from old age?

On Fri, 23 Mar 2012 22:36:09 -0400, "Michael A. Terrell"
wrote:

Ever looked at "White Trash Repairs"?


http://thereifixedit.failblog.org

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Do thermal fuses fail from old age?

Maybe their thermal fuses opened?

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Michael A. Terrell" wrote in message
m...

The Daring Dufas wrote:

P.S. They often get mad when someone like me is teasing them. o_O



Some just consider the source, and ignore you.


--
You can't have a sense of humor, if you have no sense.




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Default Do thermal fuses fail from old age?

Not only thermal fuses, as you've found. I've also seen compressor thermal
overloads hanging loose in the air. With the compressor cooking hot.

One other one I saw, was a dehumidifier (commercial model, mounted in a
cellar) that would regularly freeze over. I had a look, and find the freeze
sensor hanging in the air, rather than clipped to the (frozen) suction line.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Michael A. Terrell" wrote in message
m...

I used to subcontract electronic repair for a fire restoration
company. Most of their jobs were to repair the buildings so the heirs
could sell them. They wanted nothing to do with the place their parent
or parents died. More than one death was caused by an incompetent
repair. A thermal overload failed? No big deal: "he terminals on the
wires will push together, so all I need is some tape and I'll charge the
suckers a couple hundred dollars."

--
You can't have a sense of humor, if you have no sense.


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Default using other contractor's penetrations

Reminds me of the one time I was helping extend some HVAC duct work. The
other fellow had spent all day cutting a rectangle shaped hole in a
cinderblock wall. We came back the next day, the cable TV installer had run
a wire diagonally through our hard won duct hole. I suggested taking the
wire out with diags.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"The Daring Dufas" wrote in message
...


I was doing some control work with an engineer friend of mine I had met
when we worked on a construction project for The Star Wars "SDI" program
back in the 80's and we were installing a large HVAC control system for
a new school in the 90's and on that job, one of the young don't give a
damn electricians decided to cut and pull our control wire out of a roof
penetration conduit so he could use it. The conduit was 40' in the air
and luckily one of the other electricians told us before the ceiling was
installed. The kid's excuse for ripping out our wire was that it was in
his way and when asked why he didn't tell us so we could handle the
problem was the fact that we weren't there that day. I don't know if
personal civilian Tasers were available at the time but I would have
liked to have owned one. ^_^

TDD


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Default halon system

I'd like to hear. I've learned a litle about these, but I'm sure your first
hand experience will be interesting.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"The Daring Dufas" wrote in message
...

P.S. Some day I'll have to tell you of my adventures the with the Halon
fire suppression system I installed in Mission Control at the missile
range. o_O

TDD


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Default work place sabotage

I've seen some moments when people weren't working together. But sabotage?
It's a shame that people make life dificult for each other, on purpose.

Christopher A. Young
Learn more about Jesus
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..

"The Daring Dufas" wrote in message
...


I will no longer tolerate sabotage or someone fooling around with my
work on a construction project. I've decided the best thing to do is
call the police and file a report along with a dollar value of the
damage based on my highest hourly rate. I will definitely have one of
perpetrators jailed on felony charges if the dollar amount is enough.
The police reports come in handy for a lawsuit against a contractor
with a "Screw You!" attitude.

TDD


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"Infinite Energy 3.0" is wonderful. The creator went to a lot of trouble to
set it up.




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Default Do thermal fuses fail from old age?

My job involves repairing machines with thermal fuses. does anyone
make 20 amp or 30 amp rated ones?

the machines i repair have 15 amp thermal fuses on high inrush loads,
and the fuses fatigue fail from being close to or at their current
limit. the machines draw a instaneous 20 amps for a moment on start up

i would rather install a higher amp fuse, of the right temp, and save
tons of time and gasoline replacing the same part over and over
again.........
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Default Do thermal fuses fail from old age?

On Sat, 24 Mar 2012 09:24:35 -0700 (PDT), bob haller
wrote:

My job involves repairing machines with thermal fuses. does anyone
make 20 amp or 30 amp rated ones?


http://www.thermodisc.com/uploads/specs/TCO.pdf
G8 series goes to 25A.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Do thermal fuses fail from old age?

Jeff Liebermann wrote:
On Thu, 22 Mar 2012 10:12:07 -0400, Phil Hobbs
wrote:


Nasty cheap Chinese thermal fuses-higher rate of failure to open in a
real overtemp condition-using two in series may keep your house from
burning down, if they don't both fail the same way.



Maybe. Such guesswork would be greatly reduced if the original poster
would kindly provide the Braun model number.
https://www.google.com/search?&q=braun+coffee+maker&tbm=isch

If the coffee maker is of the drip type automatic variety, then there
are two heaters. The upper heater, that heats the water before it
goes through the coffee filter, and the warmer at the base, that keeps
the pot of coffee warm. Such a derrangement requires two thermal
fuses, one for each heater.

Incidentally, I had a really old Mr Coffee maker overheat and melt the
plastic case. The thermal fuse never blew. The consensus was that
water somehow invaded the Microtemp thermal fuse, and rusted
everything in place.


Our Bunn is a Model GRX.

The two thermal series connected fuses are both located side by side on
top of the heated water tank.

There was no accessable thermal fuse I could see located on the warmer
heater, but maybe one was buried inside it.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.
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On 3/24/2012 7:30 AM, Stormin Mormon wrote:
Reminds me of the one time I was helping extend some HVAC duct work. The
other fellow had spent all day cutting a rectangle shaped hole in a
cinderblock wall. We came back the next day, the cable TV installer had run
a wire diagonally through our hard won duct hole. I suggested taking the
wire out with diags.

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"The Daring wrote in message
...


I was doing some control work with an engineer friend of mine I had met
when we worked on a construction project for The Star Wars "SDI" program
back in the 80's and we were installing a large HVAC control system for
a new school in the 90's and on that job, one of the young don't give a
damn electricians decided to cut and pull our control wire out of a roof
penetration conduit so he could use it. The conduit was 40' in the air
and luckily one of the other electricians told us before the ceiling was
installed. The kid's excuse for ripping out our wire was that it was in
his way and when asked why he didn't tell us so we could handle the
problem was the fact that we weren't there that day. I don't know if
personal civilian Tasers were available at the time but I would have
liked to have owned one. ^_^

TDD


TDD - Please fix your newsreader so it indents the previous poster's
contribution. It's very confusing when its all at the same indent level.
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Default Do thermal fuses fail from old age?

Would it help to put two thermals, in parallel?

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"bob haller" wrote in message
...
My job involves repairing machines with thermal fuses. does anyone
make 20 amp or 30 amp rated ones?

the machines i repair have 15 amp thermal fuses on high inrush loads,
and the fuses fatigue fail from being close to or at their current
limit. the machines draw a instaneous 20 amps for a moment on start up

i would rather install a higher amp fuse, of the right temp, and save
tons of time and gasoline replacing the same part over and over
again.........




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Default Do thermal fuses fail from old age?

On Sat, 24 Mar 2012 14:04:36 -0400, "Stormin Mormon"
wrote:

Would it help to put two thermals, in parallel?


No. You could not guarantee that the current would split evenly
between the two thermal fuses. A more serious problem is that it
would require BOTH thermal fuses to blow in order to protect the
appliance.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Do thermal fuses fail from old age?

On Sat, 24 Mar 2012 13:11:45 -0400, jeff_wisnia
wrote:

Our Bunn is a Model GRX.


Thanks. Is it GRX-B, GRX-W, GRX-Basic???
http://www.walmart.com/ip/Bunn-O-Matic-10-cup-Black-Professional-Coffee-Brewer-GRX-B/4891346
http://www.bunnathome.com/products/velocity-brew/velocity-brew-gr
http://www.bunnathome.com/sites/bunnathome.com/files/GR_use&carebooklet_english.pdf
That style would require two thermal fuses. One on top and one on the
warmer. I couldn't find anyone selling internal repair parts that
might also have an exploded view showing the fuses.

Looks like it has a 3 year warranty. Find your receipt.
Support 1-800-352-2866. Call and ask.

The two thermal series connected fuses are both located side by side on
top of the heated water tank.


Well, that's the most likely to overheat, but it certainly would not
require two fuses to do the job. Something is wrong here.

There was no accessable thermal fuse I could see located on the warmer
heater, but maybe one was buried inside it.


Maybe, but more likely the factory forgot to install one on the
warmer. So they put it where it would fit easily, which is next to
the upper heater fuse. QA? Whazzat?

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default using other contractor's penetrations

On 3/24/2012 1:30 PM, mjb wrote:
On 3/24/2012 7:30 AM, Stormin Mormon wrote:
Reminds me of the one time I was helping extend some HVAC duct work. The
other fellow had spent all day cutting a rectangle shaped hole in a
cinderblock wall. We came back the next day, the cable TV installer
had run
a wire diagonally through our hard won duct hole. I suggested taking the
wire out with diags.

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"The Daring wrote in message
...


I was doing some control work with an engineer friend of mine I had met
when we worked on a construction project for The Star Wars "SDI" program
back in the 80's and we were installing a large HVAC control system for
a new school in the 90's and on that job, one of the young don't give a
damn electricians decided to cut and pull our control wire out of a roof
penetration conduit so he could use it. The conduit was 40' in the air
and luckily one of the other electricians told us before the ceiling was
installed. The kid's excuse for ripping out our wire was that it was in
his way and when asked why he didn't tell us so we could handle the
problem was the fact that we weren't there that day. I don't know if
personal civilian Tasers were available at the time but I would have
liked to have owned one. ^_^

TDD


TDD - Please fix your newsreader so it indents the previous poster's
contribution. It's very confusing when its all at the same indent level.


Actually, Stormin Mormin is the one with the broken newsreader.
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Default Do thermal fuses fail from old age?


Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.

Jeff Liebermann wrote:
On Sat, 24 Mar 2012 13:11:45 -0400, jeff_wisnia
wrote:


Our Bunn is a Model GRX.



Thanks. Is it GRX-B, GRX-W, GRX-Basic???
http://www.walmart.com/ip/Bunn-O-Matic-10-cup-Black-Professional-Coffee-Brewer-GRX-B/4891346
http://www.bunnathome.com/products/velocity-brew/velocity-brew-gr
http://www.bunnathome.com/sites/bunnathome.com/files/GR_use&carebooklet_english.pdf
That style would require two thermal fuses. One on top and one on the
warmer. I couldn't find anyone selling internal repair parts that
might also have an exploded view showing the fuses.

Looks like it has a 3 year warranty. Find your receipt.
Support 1-800-352-2866. Call and ask.


The two thermal series connected fuses are both located side by side on
top of the heated water tank.



Well, that's the most likely to overheat, but it certainly would not
require two fuses to do the job. Something is wrong here.


There was no accessable thermal fuse I could see located on the warmer
heater, but maybe one was buried inside it.



Maybe, but more likely the factory forgot to install one on the
warmer. So they put it where it would fit easily, which is next to
the upper heater fuse. QA? Whazzat?


I'm finding it somewhat hard to believe that the warmer heater would
overheat, since there's no thermostat in or on it which could fail in
the closed mode and cause such overheating.

I'll await comments from others regarding the need and/or usage of a
thermal fuse on the warmer.

Jeff
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On Sat, 24 Mar 2012 08:48:09 +1100, "Phil Allison"
wrote:

If you run it near it's rated
maximum current (usually 5A, 15A, or 30A), it will eventually get warm
enough to melt the wax and trip the fuse.


** MASSIVE BULL**** !!!!!!!!!!

With a short circuit across
the power line, the self-heating will blow the thermal fuse almost
instantly.


** Nope - it will trip the supply breaker.

With a 10 times or more overload, breakers trip in a few milliseconds.

You stupid asshole.


See: UL 60691 for testing of the the thermal fuse:
http://bbs.dianyuan.com/bbs/u/32/1122972217.pdf
Section 10.8 discusses its use as a short circuit protection
overcurrent fuse. (This is rev 3. Rev 5 is the current version).



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Default Do thermal fuses fail from old age?

On Sat, 24 Mar 2012 18:55:44 -0400, jeff_wisnia
wrote:

I'm finding it somewhat hard to believe that the warmer heater would
overheat, since there's no thermostat in or on it which could fail in
the closed mode and cause such overheating.


UL coffee maker standards:
http://ulstandardsinfonet.ul.com/scopes/1082.html
http://bbs.dianyuan.com/bbs/u/33/1127541096.pdf
Section 18.x for thermal cutoff requirements.
Section 23.x for whether a thermal cutoff is required.
Table 33.1 shows the maximum temperature rise allowed. As I read
between the lines, any part that might rise above the stated
temperatures, requires a thermal fuse.

UL 60691 for testing of the thermal fuse:
http://bbs.dianyuan.com/bbs/u/32/1122972217.pdf
Section 10.8 discusses its use as a short circuit protection fuse.

You might find this interesting:
http://www.fixya.com/search/p89511-bunn_nhb_coffee_maker/thermal_fuse
It's a different model Bunn coffee maker, but the problems are
probably similar.

I'll await comments from others regarding the need and/or usage of a
thermal fuse on the warmer.


Ah, truth by consensus and acclamation. Much as I like the concept,
I've seen it fail far too often.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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"Jeff Liberian" wrote in message
...
On Sat, 24 Mar 2012 18:55:44 -0400, Jeff_wins
wrote:



I'll await comments from others regarding the need and/or usage of a
thermal fuse on the warmer.


Ah, truth by consensus and acclamation. Much as I like the concept,
I've seen it fail far too often.


If I were to reassemble the device differently than the way it was designed,
I would be certain to run it in an area with nothing nearby that could catch
fire for a while to see if the consensus was correct. (-:

Protection devices are sometimes added to products when beta testing reveals
a potentially dangerous condition. Their requirement might not be obvious
by simple inspection later on.

I would only omit a fuse or protective device if it was impossible to find
an identical replacement. Even then, I would probably use the most similar
component I could find. We're talking about a device that's often operating
out a human's presence that has ignition potential. Bad kimshi.

--
Bobby G.



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Default halon system

"Stormin Mormon" wrote:
I'd like to hear. I've learned a litle about these, but I'm sure your first
hand experience will be interesting.

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"The Daring Dufas" wrote in message
...

P.S. Some day I'll have to tell you of my adventures the with the Halon
fire suppression system I installed in Mission Control at the missile
range. o_O

TDD


All I know, I got a little handheld unit. Aren't you suppose to vacate ?

Greg
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Well, Bob Haller said he had 15 amp thermals, and occasional 20 amp inrush.
Why would that need to be "current split evenly"? Supposing they are
carrying 15 amps and 5 amps. What's the problem?

If the thermals are properly placed, they would both melt open when the
device overheated.

And suppose one thermal fails from old age? Then, Bob is back where he was
when he started.

I don't see the big problem.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Jeff Liebermann" wrote in message
...
On Sat, 24 Mar 2012 14:04:36 -0400, "Stormin Mormon"
wrote:

Would it help to put two thermals, in parallel?


No. You could not guarantee that the current would split evenly
between the two thermal fuses. A more serious problem is that it
would require BOTH thermal fuses to blow in order to protect the
appliance.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Default Do thermal fuses fail from old age?

On Mar 25, 7:53*am, "Stormin Mormon"
wrote:
Well, Bob Haller said he had 15 amp thermals, and occasional 20 amp inrush.
Why would that need to be "current split evenly"? Supposing they are
carrying 15 amps and 5 amps. What's the problem?

If the thermals are properly placed, they would both melt open when the
device overheated.

And suppose one thermal fails from old age? Then, Bob is back where he was
when he started.

I don't see the big problem.

Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"Jeff Liebermann" wrote in message

...
On Sat, 24 Mar 2012 14:04:36 -0400, "Stormin Mormon"

wrote:
Would it help to put two thermals, in parallel?


No. *You could not guarantee that the current would split evenly
between the two thermal fuses. *A more serious problem is that it
would require BOTH thermal fuses to blow in order to protect the
appliance.

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558


I have used thermal fuses in parell. But really dont like it as it
would cause too many problems if a fire occured.

thanks for the link for the high current thermal fuses anything that
decreases my gasoline expense is well worth it.........


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Default Do thermal fuses fail from old age?

On Fri, 23 Mar 2012 13:27:05 -0700, Jeff Liebermann
wrote:

On Fri, 23 Mar 2012 12:48:47 -0700, "William Sommerwerck"
wrote:

'Course the minuscule size of today's electronics and my aging
eyesight makes it a no-win game for me to try and do much
fixing of that kind of stuff those days.


I just bought an illuminated head-mount magnifier from Harbor Freight for
$5. It's surprisingly good. The optics have little distortion and no
chromatic aberration. There are four magnifications, but the lights "focus"
at only the lowest magnification.


I don't really like the plastic head mounted magnifiers. I'm
constantly going from whatever I'm working on, to picking up tools,
soldering iron, parts, probes, etc, on the bench. I have to keep
raising and lowering the magnifier in order to switch. With an LCD
screen, everything is roughly the same distance away, so no raising or
lowering.

If I were to buy a head mounted magnifier, it will probably be a
surgical loupe.
https://www.google.com/search?q=surgical+loupe&tbm=isch
Lots of styles and types to choose from, all seriously expensive. I've
played with some and am rather impressed. If I can keep the working
distance constant, it's as good or better than my USB camera
microscope. Mounted on eyeglasses, they are a bit heavy, but headband
mounts are available.

I use magnifiers in my work regularly and have been using a camera and
display for some of the work I do. I bought a camera and lens and
display and set it up for lathe work. But I need to get better
components because some of the details I need to see accurately are
less than .001". So even though the system I put together seemed at
first to be fine it is still has problems with contrast and
distortion. One thing that has really helped with magnifiers though is
bright lights. The really bright lighting, by causing my pupils to
constrict, gives me much more depth of field.
Eric
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On Sun, 25 Mar 2012 07:53:23 -0400, "Stormin Mormon"
wrote:

Well, Bob Haller said he had 15 amp thermals, and occasional 20 amp inrush.
Why would that need to be "current split evenly"? Supposing they are
carrying 15 amps and 5 amps. What's the problem?


A 15A thermal fuse will not blow on a 20A inrush. It needs some time
to melt the wax inside the fuse and blow. I'm not sure how much is
required to blow it up reliably, but a short circuit across the line
should do the trick.

The problem with unequal current distribution is that the fusing
current is not predictable. However, you're partially correct. If
one fuse blows at some current, the full current load will transfer to
the other parallel fuse, which will then have enough current to blow.
The problem is that if it takes one minute for the first fuse to blow,
it will probably take more than an additional minute to blow the 2nd
fuse because of the higher series resistance which is what causes the
unequal current distribution in the first place. In effect, such a
derangement extends the time it takes for the power to be cut, and a
fire prevented.

If the thermals are properly placed, they would both melt open when the
device overheated.


That's a big if. Presumably, if the heating element was one
contiguous device, with no possibility of a partial short to the metal
water tank, there would be no thermal gradient across the water tank.
However, if the heater was a series of heating elements, distributed
in some artistic pattern across the bottom of the water tank, and only
a partial short occurs, the resulting thermal gradient will cause one
thermal fuse to be much hotter than the other, especially if the water
tank is empty.

And suppose one thermal fails from old age? Then, Bob is back where he was
when he started.


From: UL 60691 Pg 17
NOTE 2 For reasons of safety, it should be made clear in the
documentation that a THERMAL-LINK is a non-repairable item
and that, in case of replacement, an equivalent THERMAL-LINK
from the same manufacturer and having the same catalogue
reference should be used, mounted in exactly the same way.
This might explain why every pot warmer I could find has the plastic
base solvent welded shut, or metal base riveted together, to prevent
(or at least discourage) thermal fuse replacement.

However, in the case of the coffee machine, UL contradicts itself:
From: UL 1082 Pg 26
18.1 If an appliance is provided with a thermal cutoff, it
shall be secured in place and shall be so located that it will
be accessible for replacement without damaging other connections
or internal wiring. See 50.6.

So, one spec says it should be un repairable, while another says that
it should be accessible for replacement. Toss a coin.

Incidentally, if the thermal fuse blows, one should consider asking
why it blew. It isn't always old age or crappy quality. There may be
an intermittent or obscure fault causing it to blow.

I don't see the big problem.


Look harder and you'll see. What you're suggesting is not in itself
unsafe. It is possible to run parallel thermal fuses and still have
it perform its intended function. However, it's much safer to put
them in series.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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On Mar 25, 7:01*pm, Jeff Liebermann wrote:
On Sun, 25 Mar 2012 07:53:23 -0400, "Stormin Mormon"

wrote:
Well, Bob Haller said he had 15 amp thermals, and occasional 20 amp inrush.
Why would that need to be "current split evenly"? Supposing they are
carrying 15 amps and 5 amps. What's the problem?


A 15A thermal fuse will not blow on a 20A inrush. *It needs some time
to melt the wax inside the fuse and blow. *I'm not sure how much is
required to blow it up reliably, but a short circuit across the line
should do the trick.

The problem with unequal current distribution is that the fusing
current is not predictable. *However, you're partially correct. *If
one fuse blows at some current, the full current load will transfer to
the other parallel fuse, which will then have enough current to blow.
The problem is that if it takes one minute for the first fuse to blow,
it will probably take more than an additional minute to blow the 2nd
fuse because of the higher series resistance which is what causes the
unequal current distribution in the first place. *In effect, such a
derangement extends the time it takes for the power to be cut, and a
fire prevented.

If the thermals are properly placed, they would both melt open when the
device overheated.


That's a big if. *Presumably, if the heating element was one
contiguous device, with no possibility of a partial short to the metal
water tank, there would be no thermal gradient across the water tank.
However, if the heater was a series of heating elements, distributed
in some artistic pattern across the bottom of the water tank, and only
a partial short occurs, the resulting thermal gradient will cause one
thermal fuse to be much hotter than the other, especially if the water
tank is empty.

And suppose one thermal fails from old age? Then, Bob is back where he was
when he started.


From: UL 60691 Pg 17
* *NOTE 2 For reasons of safety, it should be made clear in the
* *documentation that a THERMAL-LINK is a non-repairable item
* *and that, in case of replacement, an equivalent THERMAL-LINK
* *from the same manufacturer and having the same catalogue
* *reference should be used, mounted in exactly the same way.
This might explain why every pot warmer I could find has the plastic
base solvent welded shut, or metal base riveted together, to prevent
(or at least discourage) thermal fuse replacement.

However, in the case of the coffee machine, UL contradicts itself:
From: UL 1082 Pg 26
* *18.1 If an appliance is provided with a thermal cutoff, it
* *shall be secured in place and shall be so located that it will
* *be accessible for replacement without damaging other connections
* *or internal wiring. See 50.6.

So, one spec says it should be un repairable, while another says that
it should be accessible for replacement. *Toss a coin.

Incidentally, if the thermal fuse blows, one should consider asking
why it blew. *It isn't always old age or crappy quality. *There may be
an intermittent or obscure fault causing it to blow.

I don't see the big problem.


Look harder and you'll see. *What you're suggesting is not in itself
unsafe. *It is possible to run parallel thermal fuses and still have
it perform its intended function. *However, it's much safer to put
them in series.

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558


a 15 amp thermal fuse on a high inrush load causes premature failure
of the fuse, not from device malfunction but the repeated high current
rush.

this can and does cause cause the thermal fuse to fail while the
device is fine.

with gasoline so expensive i want to minimize unnecessary calls. they
annoy the customer and waste my time.//

I am ordering some high current thermal fuses in the AM
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Default Do thermal fuses fail from old age?

On Sun, 25 Mar 2012 20:24:33 -0700 (PDT), bob haller
wrote:

a 15 amp thermal fuse on a high inrush load causes premature failure
of the fuse, not from device malfunction but the repeated high current
rush.

this can and does cause cause the thermal fuse to fail while the
device is fine.

with gasoline so expensive i want to minimize unnecessary calls. they
annoy the customer and waste my time.//

I am ordering some high current thermal fuses in the AM


What is the device? I ask because it might be easier to install a
thermistor inrush current limiter on the input power leads, than a
bigger thermal fuse.

Inrush current limiting devices:
http://www.ametherm.com/inrush-current/
http://www.rtie.com/category-s/48.htm
According to the data sheets they have devices rated from 1 to 36
amps.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Do thermal fuses fail from old age?

On 3/25/2012 11:08 PM, Jeff Liebermann wrote:
On Sun, 25 Mar 2012 20:24:33 -0700 (PDT), bob
wrote:

a 15 amp thermal fuse on a high inrush load causes premature failure
of the fuse, not from device malfunction but the repeated high current
rush.

this can and does cause cause the thermal fuse to fail while the
device is fine.

with gasoline so expensive i want to minimize unnecessary calls. they
annoy the customer and waste my time.//

I am ordering some high current thermal fuses in the AM


What is the device? I ask because it might be easier to install a
thermistor inrush current limiter on the input power leads, than a
bigger thermal fuse.

Inrush current limiting devices:
http://www.ametherm.com/inrush-current/
http://www.rtie.com/category-s/48.htm
According to the data sheets they have devices rated from 1 to 36
amps.


Back about 4 decades when I tried my hand at TV repair, me and the guys
I worked with had to replace a lot of what were called
"glowbars/globars", they were actually PTC devices hooked to the
degaussing coil around the CRT of a TV set to power the degaussing coil
for a short period every time a TV set was turned on. When you first
turn on a TV or CRT monitor equipped with one you may hear a "GRONK"
sound and that's the degaussing circuit. The PTC thermistor allows a big
rush of current to the coil until it heats up which causes its
resistance to increase stopping the flow of current until it cools off.
There could be a way to use a globar and one of those mil spec power
resistors in that finned aluminum case that has mounting ears and one
flat surface. The resister could be epoxied to the metal in the
appliance and hooked in series with the thermistor across the incoming
power to temper any inrush current before it hit the heating element
circuit. I see several diagrams forming in my mind's eye including one
with a low value power resister in series with the heating element
connected to the thermistor circuit and another with an NTC device in
series with the heating element and the power. The only problem would be
coming up with a thermistor that could handle the current of the heating
element when it's connected in series with it. Oh well, it's my mind,
I'll have fun playing in there. ^_^

TDD
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