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Fridge Thermal fuse in series with Defrost Heater........

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Denny B

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Feb 7, 2003, 3:55:25 AM2/7/03
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Fridge is not defrosting and there is severe ice build up.
Checked the defrost heater element with an ohm meter
and it is OK.
There is a Thermal Fuse in series with the defrost heater
and it is open.
My problem is on the diagram it does not state what the
value of the fuse is in amps. It just states set to open at 140 to 150
degrees F.

Anybody have an idea what the fuse should be rated at in amps?

Make of fridge Admiral System 2000
Model # AAT-6700
Type TFA-16

thanks in advance
Denny B


Sam Goldwasser

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Feb 7, 2003, 8:05:03 AM2/7/03
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"Denny B" <dmrb...@sprint.ca> writes:

> Fridge is not defrosting and there is severe ice build up.
> Checked the defrost heater element with an ohm meter
> and it is OK.
> There is a Thermal Fuse in series with the defrost heater
> and it is open.
> My problem is on the diagram it does not state what the
> value of the fuse is in amps. It just states set to open at 140 to 150
> degrees F.

Assuming this is a one-time thermal fuse (not the defrost thermostat), then
you need to figure the normal current to the defrost heater and make sure
the replacement can handle that.

However, if it blew, could just be a quirk but may also mean there is
a problem in the heater circuit or the defrost thermostat isn't working
and it's getting too hot.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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Gary Tait

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Feb 7, 2003, 2:36:12 PM2/7/03
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There is no "amperage" rating on them to be concerned of. the Temperature
value is the one you match. Get one the same physical size will be enough amps.

Denny B

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Feb 8, 2003, 12:17:08 AM2/8/03
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"Gary Tait" <ta...@hurontel.on.ca> wrote in message
news:nh284v0h4qu40qfpm...@4ax.com...

Gary, thanks kindly.

thanks
Denny B


Asimov

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Feb 8, 2003, 10:19:16 PM2/8/03
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"Denny B" wrote to "All" (07 Feb 03 01:55:25)
--- on the topic of "Fridge Thermal fuse in series with Defrost Heater........"

It's a thermal "cut-out" so it should have 0 ohms as the current is
limited by the standardized heating element (maybe a few hundred
watts). I think there isn't really a current rating but it will reset
itself. If it stayed open then replace it. Have you checked the timer
clock turns, advancing the sequence switch, and not jammed in the run
position?

DB> From: "Denny B" <dmrb...@sprint.ca>

DB> Fridge is not defrosting and there is severe ice build up.
DB> Checked the defrost heater element with an ohm meter
DB> and it is OK.
DB> There is a Thermal Fuse in series with the defrost heater
DB> and it is open.
DB> My problem is on the diagram it does not state what the
DB> value of the fuse is in amps. It just states set to open at 140 to 150
DB> degrees F.

DB> Anybody have an idea what the fuse should be rated at in amps?

DB> Make of fridge Admiral System 2000
DB> Model # AAT-6700
DB> Type TFA-16

DB> thanks in advance
DB> Denny B


Jim Adney

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Feb 9, 2003, 12:34:57 AM2/9/03
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On Fri, 7 Feb 2003 01:55:25 -0700 "Denny B" <dmrb...@sprint.ca>
wrote:

It's probably a thermal breaker rather than a thermal fuse. The
difference is that the breaker will reset itself when the temp comes
back down.

My defrost heater coil failed many years ago and the repairman
explained that there was a temp sensor in there which turned off the
heater once things got warm enough to indicate that the ice was all
melted, so I assume this was at something like 33 degrees.

Your defroster is run by a timer which sends power to the defrost coil
for one hour out of every 13 (at least that's how mine works.)
Although the power is applied for a full hour, the thermal breaker
shuts the heater off as soond as the job's done, so you don't heat
things up more than necessary.

It's also possible that you have an actual thermal fuse there, but
this would be strange in a freezer.

I have had good luck locally with an appliance parts store here. They
can usually tell me what part I need if there's any question.

-
-----------------------------------------------
Jim Adney jad...@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

Sam Goldwasser

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Feb 9, 2003, 7:59:19 AM2/9/03
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Note that there is normally also a defrost thermostat that opens above 32
degrees F. So, the overall circuit will appear open at room temp.

Sam Goldwasser

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Feb 9, 2003, 8:00:57 AM2/9/03
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Jim Adney <jad...@vwtype3.org> writes:

> It's probably a thermal breaker rather than a thermal fuse. The
> difference is that the breaker will reset itself when the temp comes
> back down.

Yes, there should be one. But he said it had a high temperature rating.
The defrost thermostat will be set around 32 degrees to open when there
is no more ice.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

> My defrost heater coil failed many years ago and the repairman

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