Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

Karl Townsend wrote:

Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

Just make a probe with standard K type thermocouple wire, do a tiny weld
at the end. It's only the temp of the junction that counts.
http://www.omega.com/ppt/pptsc.asp?r...IRE&Nav=temh06
Looks like they have a 100' min but that would be enough for multiple
probes.

Pete C. wrote:
Karl Townsend wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

RoyJ wrote:

Just make a probe with standard K type thermocouple wire, do a tiny weld
at the end. It's only the temp of the junction that counts.
http://www.omega.com/ppt/pptsc.asp?r...IRE&Nav=temh06
Looks like they have a 100' min but that would be enough for multiple
probes.

Yea, you can roll your own, and McMaster has TC wire as well. I expect
the OP just want's to get the job done, and not practice TIG welding his
own thermocouples however.

Pete C.



Pete C. wrote:
Karl Townsend wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

"Karl Townsend" wrote: (clip) My old tired eyes almost can't see the dial
anymore, trying to look through bifocals to the ceiling while holding a
flashlight (clip)
^^^^^^^^^^^^^^^^^
1.) Flashlight with a headband. Available at Harbor Freight.
2.) Glasses with a bifocal element at the top. They are made for
librarians (who have to read stuff on the higher shelves) and people who
have to read meters and gauges that are above eye level. I used to have a
pair, and they are also good for working off a creeper under the car.

"Remote sensor thermostat". I got one last fall for the apartments -
the sensor is in one apartment on the 2nd floor and the thermostat is in
the basement. Just ran ordinary wire between them. Don't remember the
model, but it is Honeywell & I got it on eBay. IIRC, it was a model
that could be either internal or remote sensor, switch or option selected.

Bob

Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

Help me out with thermocouple vs. thermister.

My understanding, thermocouples are just a joint of two dissimilar metals.
can measure temperature over a large range, but can't control accurately to
a small range of control. I'm after +/- 1 degree F or better

Thermistors are a temperature sensitive resistor with less range and more
accuracy, and can do +/- 1 degree control.

The only thermistor controller in McmasterCarr is the one I'm asking about.

Karl

Yeah, but Karl's son is one of those TIG welder guys that practices on
beer cans. For what he wants to do, welding his own seems like the best
choice.

I didn't find the TC wire in McMaster, used the Omega site since it had
a good writeup.

I've always used 'K' wire, you mentioned 'J'. Why/Comments?

Pete C. wrote:
RoyJ wrote:
Just make a probe with standard K type thermocouple wire, do a tiny weld
at the end. It's only the temp of the junction that counts.
http://www.omega.com/ppt/pptsc.asp?r...IRE&Nav=temh06
Looks like they have a 100' min but that would be enough for multiple
probes.

Yea, you can roll your own, and McMaster has TC wire as well. I expect
the OP just want's to get the job done, and not practice TIG welding his
own thermocouples however.

Pete C.


Pete C. wrote:
Karl Townsend wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl
Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

My 'K' thermocouple thermometer reads in 1/10s of degree F.

The 'K' junction gnerates about .23 milivolts per degree in the temp
range you are interested. Sensitivity is a function of the controller.
http://www.omega.com/temperature/Z/pdf/z218-220.pdf

Karl Townsend wrote:
Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

Help me out with thermocouple vs. thermister.

My understanding, thermocouples are just a joint of two dissimilar metals.
can measure temperature over a large range, but can't control accurately to
a small range of control. I'm after +/- 1 degree F or better

Thermistors are a temperature sensitive resistor with less range and more
accuracy, and can do +/- 1 degree control.

The only thermistor controller in McmasterCarr is the one I'm asking about.

Karl

Check with the industrial sales rep for Honeywell HVAC instruments. I
have some older Honeywell units that have 50' capillary tubes. I didn't
see any of these in the McMaster catalog.

Karl Townsend wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

RoyJ wrote:

Yeah, but Karl's son is one of those TIG welder guys that practices on
beer cans. For what he wants to do, welding his own seems like the best
choice.

Certainly an option. Save a few $ in TC connectors.


I didn't find the TC wire in McMaster, used the Omega site since it had
a good writeup.

McMaster page 541, bottom.


I've always used 'K' wire, you mentioned 'J'. Why/Comments?

No particular reason, just first in the list of supported TC types for
the controller.







Pete C. wrote:
RoyJ wrote:
Just make a probe with standard K type thermocouple wire, do a tiny weld
at the end. It's only the temp of the junction that counts.
http://www.omega.com/ppt/pptsc.asp?r...IRE&Nav=temh06
Looks like they have a 100' min but that would be enough for multiple
probes.

Yea, you can roll your own, and McMaster has TC wire as well. I expect
the OP just want's to get the job done, and not practice TIG welding his
own thermocouples however.

Pete C.


Pete C. wrote:
Karl Townsend wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl
Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

Karl Townsend wrote:

Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

Help me out with thermocouple vs. thermister.

My understanding, thermocouples are just a joint of two dissimilar metals.
can measure temperature over a large range, but can't control accurately to
a small range of control. I'm after +/- 1 degree F or better

Thermistors are a temperature sensitive resistor with less range and more
accuracy, and can do +/- 1 degree control.

The only thermistor controller in McmasterCarr is the one I'm asking about.

Karl

Exact opposite, thermocouples are much more accurate than thermisters.
Thermisters are cheaper than thermocouples, and good enough for consumer
stuff like on PC cooling fans.

"Pete C." wrote:

Karl Townsend wrote:

Thermistor temp probes can definitely be lengthened within reason and
just need a little recalibration perhaps.

If you want to do things the correct industrial way, you use a real
industrial temperature controller like 38615K13 on page 544 with a
thermocouple type sensor (pick a type J on page 538) you can readily
locate anywhere (type J extension on page 542)

Help me out with thermocouple vs. thermister.

My understanding, thermocouples are just a joint of two dissimilar metals.
can measure temperature over a large range, but can't control accurately to
a small range of control. I'm after +/- 1 degree F or better

Thermistors are a temperature sensitive resistor with less range and more
accuracy, and can do +/- 1 degree control.

The only thermistor controller in McmasterCarr is the one I'm asking about.

Karl

Exact opposite, thermocouples are much more accurate than thermisters.
Thermisters are cheaper than thermocouples, and good enough for consumer
stuff like on PC cooling fans.

Additionally the autotuning PID controller referenced will learn the
response times of your refrigeration system and tune itself for very
tight control.

On Sun, 09 Sep 2007 02:56:39 GMT, "Pete C."
wrote:

RoyJ wrote:

Yeah, but Karl's son is one of those TIG welder guys that practices on
beer cans. For what he wants to do, welding his own seems like the best
choice.

Certainly an option. Save a few $ in TC connectors.


I didn't find the TC wire in McMaster, used the Omega site since it had
a good writeup.

McMaster page 541, bottom.


I've always used 'K' wire, you mentioned 'J'. Why/Comments?

No particular reason, just first in the list of supported TC types for
the controller.


snip

J t/c's come on a lot of stuff because they're cheaper. They work
fine, but don't use one around moisture or corrosive environments. The
iron (J = iron/constantan) will corrode and fail. Actually, when I
need as much accuracy as I can get, I use RTD's. Most temp
controllers support them, and the signal is much more robust than the
t/c millivolt signal. I have them assembled with Brad Harrison
Nanochange connectors by Sandelius in Houston. That makes it easy to
swap in a spare. The normal four prong connector made from two t/c
connectors of copper is too big and clunky.

I still use J's when they come installed by the OEM. But when I use
them, I calibrate the entire loop with a dry block tester at least
once per year. I have found that J's will drift significantly over a
period of years in a temperature cycling application, like an oven or
an extruder that doesn't run continuously.

Pete Keillor

Karl Townsend wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

There are standard thermostats with a capillary tube and a
remote sensing bulb. Generally, they con'd come with VERY long
tubes, but 6 feet is no problem. You should be able to put the
part with the dial in a more convenient place. You should be
able to find these at a refrigeration supply outfit.

Jon

On Sep 8, 3:40 pm, "Karl Townsend"
wrote:
Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 ofhttp://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

Make sure you're dealing with a thermistor, not a thermocouple.
Thermistors are "thermal resistors" and can use regular copper wire
for hook up. Thermocouples use two different types of materials and
require the same pairing for hookup wire. One causes a varying
voltage drop to an applied voltage, the other generates a (small)
varying voltage. Temperature controls can be designed to use one or
the other, but they don't substitute types without some redesign. With
a thermistor, you may have to adjust for the voltage drop of the
additional wire, the temperature control may think it's cooler(or
warmer) than it really is because of the additional resistance,
depends on the coefficient of the thermistor, positive or negative.

Stan

On Sat, 8 Sep 2007 16:40:09 -0500, "Karl Townsend"
wrote:

Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

I used the Penn A419 (1760K77) on a Sauna where nothing else worked,
too cool for an oven stat, too hot for a room... It's fine except
when one of the residents tries messing with anything other than the
setpoint - it's either totally locked or totally unlocked, no
'setpoint change only' option... Then I have to go and reset it.

They have factory longer lead thermistor sensors available. Put it
in conduit for damage protection. And the Penn has nifty features -
all the setpoints and timing is programmable...

-- Bruce --

I used the Penn A419 (1760K77) on a Sauna where nothing else worked,
too cool for an oven stat, too hot for a room... It's fine except
when one of the residents tries messing with anything other than the
setpoint - it's either totally locked or totally unlocked, no
'setpoint change only' option... Then I have to go and reset it.

They have factory longer lead thermistor sensors available. Put it
in conduit for damage protection. And the Penn has nifty features -
all the setpoints and timing is programmable...

-- Bruce --

BINGO! I'm orderring two on Monday. McMaster doesn't list the long lead
but says they are available. Can you suggest a vendor to just order from?

Karl

On Sun, 9 Sep 2007 08:23:00 -0500, "Karl Townsend"
wrote:

I used the Penn A419 (1760K77) on a Sauna where nothing else worked,
too cool for an oven stat, too hot for a room... It's fine except
when one of the residents tries messing with anything other than the
setpoint - it's either totally locked or totally unlocked, no
'setpoint change only' option... Then I have to go and reset it.

They have factory longer lead thermistor sensors available. Put it
in conduit for damage protection. And the Penn has nifty features -
all the setpoints and timing is programmable...

BINGO! I'm orderring two on Monday. McMaster doesn't list the long lead
but says they are available. Can you suggest a vendor to just order from?

You can use the thermistor that comes with it and splice on some
more wire - ISTR that there's a gauge restriction, but not onerous -
needs 18 Ga or 16 Ga copper thermostat wire.

Might call for twisted, but that's used as speaker wire for home
theatre pre-installs. Available at The Borg.

If McMaster gives you a long lead time, try a local refrigeration
house - Johnstone Supply is national, and has locations everywhere.

-- Bruce --

On Sat, 8 Sep 2007 16:40:09 -0500, "Karl Townsend"
wrote:

Each of the evaporators in the apple cooler has a thermostat like item C on
page 603 of http://www.mcmaster.com/ They are mounted on the 13' ceiling in
the dark area behind the evaporator. I have to climb to the top of a 10 foot
step ladder to adjust them and they need several adjustments per season. My
old tired eyes almost can't see the dial anymore, trying to look through
bifocals to the ceiling while holding a flashlight and leaning over a stack
of apple boxes just ain't fun.

So, I'm looking for a better thermostat. First I looked at an electronic
thermostat - item E on the same Mcmaster page 603. I could move it about
four foot down the wall as it has a longer bulb length. That would put it
9-10' high on the wall. easier to see but still need a ladder.

Then I noticed item 331K21 on page 544. If I could lengthen the cables from
3' to 30', the control unit could be placed near the cooler walk door at eye
level - no more ladder. It says the sensor is a thermistor probe with a 3.5'
cable. So, can a thermistor probe cable be lengthened?

Or, any other good suggestions? I'd really like to adjust cooler set point
without a ladder and at the front of the room if at all possible. The back
evaporator often gets stacked in. FWIW, any thermostat just energizes a 220
VAC solenoid to let the refrigerant flow.

Karl

You can extend thermistor lines 30 feet or so with no problem. The
additional resistance in the wiring might change the setpoint a
fraction of a degree, oh dear. Given all the other stuff you have
running, it wouldn't hurt and might help to use shielded cable.

RoyJ writes:
Yeah, but Karl's son is one of those TIG welder guys that practices on
beer cans. For what he wants to do, welding his own seems like the best
choice.

I once built a bunch of thermocouple junctions for a science experiment.
All that was needed was stripping a bit of insulation from the end of
the TC cable, twisting or otherwise putting the two wires in contact at
their ends, and a moment in an oxyacetylene torch flame.

Dave

"Leo Lichtman" writes:

2.) Glasses with a bifocal element at the top. They are made for
librarians (who have to read stuff on the higher shelves) and people who
have to read meters and gauges that are above eye level. I used to have a
pair, and they are also good for working off a creeper under the car.

And airline pilots, who have to read complex display panels overhead.

Dave

On Wed, 12 Sep 2007 01:48:17 +0000, Dave Martindale wrote:
"Leo Lichtman" writes:

2.) Glasses with a bifocal element at the top. They are made for
librarians (who have to read stuff on the higher shelves) and people who
have to read meters and gauges that are above eye level. I used to have a
pair, and they are also good for working off a creeper under the car.

And airline pilots, who have to read complex display panels overhead.

And even aircraft mechanics, and I suppose car mechanics. :-)

Cheers!
Rich