Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Whatever 80/K stands for it is not 80 deg K. A temp of 80 deg. K would
be -193 deg C or -316 deg F!

While the K is curious, 80 deg C at least would be a more reasonable
temperature. Perhaps you can short out the bad sensor and measure the
operating temperature of the heat sink during use with a thermocouple.
Add some factor say 20% to the number and compare that to the
temperature limit for the output MOSFETs. That would give you a
temperature range for a substitute thermal sensor.

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Whatever 80/K stands for it is not 80 deg K. A temp of 80 deg. K would
be -193 deg C or -316 deg F!

While the K is curious, 80 deg C at least would be a more reasonable
temperature. Perhaps you can short out the bad sensor and measure the
operating temperature of the heat sink during use with a thermocouple.
Add some factor say 20% to the number and compare that to the
temperature limit for the output MOSFETs. That would give you a
temperature range for a substitute thermal sensor.

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Whatever 80/K stands for it is not 80 deg K. A temp of 80 deg. K would
be -193 deg C or -316 deg F!

While the K is curious, 80 deg C at least would be a more reasonable
temperature. Perhaps you can short out the bad sensor and measure the
operating temperature of the heat sink during use with a thermocouple.
Add some factor say 20% to the number and compare that to the
temperature limit for the output MOSFETs. That would give you a
temperature range for a substitute thermal sensor.

Robert,

You are correct about the temperature not being 80 degrees K, however
that is how the part is marked, it could be 80 degrees centigrade and
the /K could be a tolerance. However, at room temperature the part
should read as a short, and on the defective one the case is physically
burnt up. The one in the other channel is OK, though I do not have a
temperature probe to see at what temperature it trips open.

Regards,
Tim Schwartz
Bristol Electronics


Robert Gault wrote:

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Whatever 80/K stands for it is not 80 deg K. A temp of 80 deg. K would
be -193 deg C or -316 deg F!

While the K is curious, 80 deg C at least would be a more reasonable
temperature. Perhaps you can short out the bad sensor and measure the
operating temperature of the heat sink during use with a thermocouple.
Add some factor say 20% to the number and compare that to the
temperature limit for the output MOSFETs. That would give you a
temperature range for a substitute thermal sensor.

Robert,

You are correct about the temperature not being 80 degrees K, however
that is how the part is marked, it could be 80 degrees centigrade and
the /K could be a tolerance. However, at room temperature the part
should read as a short, and on the defective one the case is physically
burnt up. The one in the other channel is OK, though I do not have a
temperature probe to see at what temperature it trips open.

Regards,
Tim Schwartz
Bristol Electronics


Robert Gault wrote:

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Whatever 80/K stands for it is not 80 deg K. A temp of 80 deg. K would
be -193 deg C or -316 deg F!

While the K is curious, 80 deg C at least would be a more reasonable
temperature. Perhaps you can short out the bad sensor and measure the
operating temperature of the heat sink during use with a thermocouple.
Add some factor say 20% to the number and compare that to the
temperature limit for the output MOSFETs. That would give you a
temperature range for a substitute thermal sensor.

Robert,

You are correct about the temperature not being 80 degrees K, however
that is how the part is marked, it could be 80 degrees centigrade and
the /K could be a tolerance. However, at room temperature the part
should read as a short, and on the defective one the case is physically
burnt up. The one in the other channel is OK, though I do not have a
temperature probe to see at what temperature it trips open.

Regards,
Tim Schwartz
Bristol Electronics


Robert Gault wrote:

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Whatever 80/K stands for it is not 80 deg K. A temp of 80 deg. K would
be -193 deg C or -316 deg F!

While the K is curious, 80 deg C at least would be a more reasonable
temperature. Perhaps you can short out the bad sensor and measure the
operating temperature of the heat sink during use with a thermocouple.
Add some factor say 20% to the number and compare that to the
temperature limit for the output MOSFETs. That would give you a
temperature range for a substitute thermal sensor.

Tim,

If memory serves me correctly I believe the Hafler thermal switches tripped at
around 65C. The place below used to have a variety of thermal switches listed in
its catalog:

http://www.meci.com/

Hope this helps...........

Tim Schwartz wrote:

Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Tim,

If memory serves me correctly I believe the Hafler thermal switches tripped at
around 65C. The place below used to have a variety of thermal switches listed in
its catalog:

http://www.meci.com/

Hope this helps...........

Tim Schwartz wrote:

Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

Tim,

If memory serves me correctly I believe the Hafler thermal switches tripped at
around 65C. The place below used to have a variety of thermal switches listed in
its catalog:

http://www.meci.com/

Hope this helps...........

Tim Schwartz wrote:

Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics

In article , Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics


If Elmwood says the part is still available, they should be able to
provide you with a complete part number, specs, and a list of their
distributors. One of the distis should then be able to help you out at
a lot less than $50. Have you tried this route?

Steve

In article , Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics


If Elmwood says the part is still available, they should be able to
provide you with a complete part number, specs, and a list of their
distributors. One of the distis should then be able to help you out at
a lot less than $50. Have you tried this route?

Steve

In article , Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a $750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics


If Elmwood says the part is still available, they should be able to
provide you with a complete part number, specs, and a list of their
distributors. One of the distis should then be able to help you out at
a lot less than $50. Have you tried this route?

Steve

Sometimes companies like this will provide a "sample" for you to test.

Just a thought.


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stephan Goldstein" wrote in message
...
In article , Tim Schwartz
wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker
(Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell
and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a
$750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics


If Elmwood says the part is still available, they should be able to
provide you with a complete part number, specs, and a list of their
distributors. One of the distis should then be able to help you out at
a lot less than $50. Have you tried this route?

Steve

Sometimes companies like this will provide a "sample" for you to test.

Just a thought.


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stephan Goldstein" wrote in message
...
In article , Tim Schwartz
wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker
(Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell
and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a
$750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics


If Elmwood says the part is still available, they should be able to
provide you with a complete part number, specs, and a list of their
distributors. One of the distis should then be able to help you out at
a lot less than $50. Have you tried this route?

Steve

Sometimes companies like this will provide a "sample" for you to test.

Just a thought.


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stephan Goldstein" wrote in message
...
In article , Tim Schwartz
wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker
(Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

The original is made by Elmwood Sensor, a division of Honeywell
and is
a 2450 series (the number is molded into the plastic on the top of the
sensor). Other lettering around the side of the defective one is
"87-232 L167 80/K", where 87-232 is likely the date code (232nd day of
1987), no idea about the L167, and 80/K the temperature where it trips.

I've contacted Elmwood and the part is still available, with a
$750
minimum order, so that is not one of my choices. I believe the DH-120,
DH-200, DH-220 and DH-500 all use the same part. Does anyone have a
parts unit that might have a good thermal circuit breaker that they
would be willing to part with? (Please note that on the DH-500 there is
also a thermal sensor to turn on the fan, which is NOT a substitute.)

Thanks for your time,
Tim Schwartz
Bristol Electronics


If Elmwood says the part is still available, they should be able to
provide you with a complete part number, specs, and a list of their
distributors. One of the distis should then be able to help you out at
a lot less than $50. Have you tried this route?

Steve

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

Try the various surplus dealers. You probably want a N/C thermal switch that
opens around 70-80 C, and will handle 15 amps of 120 VAC.

For example:

http://www.electronicsurplus.com/dictionary/cat2115.htm

http://www.allelectronics.com/cgi-bi...765&type=store

http://www.surplussales.com/Thermal/Theraml-1.html

http://www.meci.com/default.asp?mode...s&category=515

http://www.mainlinegroup.co.uk/mless...sort=05&page=2

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

Try the various surplus dealers. You probably want a N/C thermal switch that
opens around 70-80 C, and will handle 15 amps of 120 VAC.

For example:

http://www.electronicsurplus.com/dictionary/cat2115.htm

http://www.allelectronics.com/cgi-bi...765&type=store

http://www.surplussales.com/Thermal/Theraml-1.html

http://www.meci.com/default.asp?mode...s&category=515

http://www.mainlinegroup.co.uk/mless...sort=05&page=2

Tim Schwartz wrote:
Hello all,

I'm trying to find a replacement thermal circuit breaker (Schematic
location TB1 and TB2) for a Hafler DH-500 the part number is SF-024 in
the earlier manual, or 332002 in the later manual. The part is no
longer available from Hafler.

Try the various surplus dealers. You probably want a N/C thermal switch that
opens around 70-80 C, and will handle 15 amps of 120 VAC.

For example:

http://www.electronicsurplus.com/dictionary/cat2115.htm

http://www.allelectronics.com/cgi-bi...765&type=store

http://www.surplussales.com/Thermal/Theraml-1.html

http://www.meci.com/default.asp?mode...s&category=515

http://www.mainlinegroup.co.uk/mless...sort=05&page=2