Discussion:
Defrost timer question - knobs
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Gib Bogle
2021-10-11 21:01:02 UTC
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Sorry to belabour this issue.
I have located a source of a timer with the same model number as mine, 1415435. The odd thing is that the shop has two timers with this model number, identical except for the plastic knob. They are shown on this page:
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on the second row. The top one is $93, the other is $45. You can easily see that everything about them is the same except for the knob.
I queried the supplier about the price difference. His response:
"Which one look like yours you need to buy that , that grey knob is there for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is black not white, is otherwise identical as far as I can see. The knob is shaped like the one on the $93 timer, with the two cams.

Does the knob really have a purpose? It is clear that on my fridge it doesn't touch anything as it turns.
Rod Speed
2021-10-11 21:16:20 UTC
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Post by Gib Bogle
Sorry to belabour this issue.
I have located a source of a timer with the same model number as mine,
1415435. The odd thing is that the shop has two timers with this model
number, identical except for the plastic knob. They are shown on this
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on
the second row. The top one is $93, the other is $45. You can easily see
that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is
black not white, is otherwise identical as far as I can see. The knob is
shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it
doesn't touch anything as it turns.
That may well be the problem with yours, that it should touch something as
it turns.

Unlikely that the knob is just decoration.
Gib Bogle
2021-10-11 21:25:14 UTC
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Post by Rod Speed
Post by Gib Bogle
Sorry to belabour this issue.
I have located a source of a timer with the same model number as mine,
1415435. The odd thing is that the shop has two timers with this model
number, identical except for the plastic knob. They are shown on this
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on
the second row. The top one is $93, the other is $45. You can easily see
that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there
for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is
black not white, is otherwise identical as far as I can see. The knob is
shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it
doesn't touch anything as it turns.
That may well be the problem with yours, that it should touch something as
it turns.
Unlikely that the knob is just decoration.
It clearly wasn't a problem for more than 20 years.
Rod Speed
2021-10-11 23:11:35 UTC
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Post by Gib Bogle
Post by Rod Speed
Post by Gib Bogle
Sorry to belabour this issue.
I have located a source of a timer with the same model number as mine,
1415435. The odd thing is that the shop has two timers with this model
number, identical except for the plastic knob. They are shown on this
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on
the second row. The top one is $93, the other is $45. You can easily see
that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there
for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is
black not white, is otherwise identical as far as I can see. The knob is
shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it
doesn't touch anything as it turns.
That may well be the problem with yours, that it should touch something as
it turns.
Unlikely that the knob is just decoration.
It clearly wasn't a problem for more than 20 years.
But it may have changed recently.
Peeler
2021-10-12 08:24:56 UTC
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On Tue, 12 Oct 2021 10:11:35 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Bod addressing abnormal senile quarreller Rodent:
"Do you practice arguing with yourself in an empty room?"
MID: <***@mid.individual.net>
Peeler
2021-10-11 22:01:21 UTC
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On Tue, 12 Oct 2021 08:16:20 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Marland revealing the senile sociopath's pathology:
"You have mentioned Alexa in a couple of threads recently, it is not a real
woman you know even if it is the only thing with a female name that stays
around around while you talk it to it.
Poor sad git who has to resort to Usenet and electronic devices for any
interaction as all real people run a mile to get away from you boring them
to death."
MID: <***@mid.individual.net>
Paul
2021-10-12 08:03:21 UTC
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Post by Gib Bogle
Sorry to belabour this issue.
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on the second row. The top one is $93, the other is $45. You can easily see that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is black not white, is otherwise identical as far as I can see. The knob is shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it doesn't touch anything as it turns.
The knob just indicates the position in the defrost cycle

Loading Image...

As for the pin numbering, the devices vary in the order they number
the pins. The pins have defined functions. If subbing, you have to
make sure you're connecting the wires to the pin function it belongs
with. These substitutes are not exact visual substitutes, but
"functional" substitutes. You, the installer, have to be aware
how to rewire the unit when installing it. If the original was 1234
and the sub is 4321, the wiring order would need to be reversed.
This is (obviously) a bitch, when the original timer has no numbers
at all on it :-/

https://www.tampaapplianceparts.com/blog/how-does-a-defrost-timer-work/

"Basics of How a Defrost Timer Works

The defrost timer has four pins labeled from 1 to 4.
Each pin has its own function in the operation of the timer.

Pin 1: The main input power is attached to pin 1.
Pin 2: When in defrost mode, the power (pin 1) connects to pin 2,
which activates the defrost mode. Most defrost timers stay
in defrost mode for 30 minutes.
Pin 3: This is your ground / neutral wire. It will be separated
from the other three pins.
Pin 4: When the timer is not in defrost mode, the power (pin 1)
connects to pin 4, which activates the compressor and fan.
Most timers stay in this mode for 10 hours.

To test if the defrost mode is working, apply voltage to pin 1.
When the power supply is turned on, you should be able to measure
the voltage on pin 2.

Once the timer advances past 30 minutes, the compressor and fan
should turn on. You will know that the defrost timer is working
if you measure voltage on pin 4 when the timer is not in defrost mode.

The compressor and fan pin should be active for 10 hours (or however
long your defrost timer is designed to run). Once the 10 hours is over,
the defrost timer will switch back to pin 2, activating the defrost.
"

On mine, when the clockwork drive is in position and plastic gear mated,
I cannot move the indicator with my fingers. However, if the clockwork
drive is rotated out of position (I drilled out the two ally rivets), then
I can advance the indicator in the clockwise direction, and hear
"click-clunk". At the highest position on the indicator, the defrost
turns on. And 30 minutes later on the dial, it turns off. The cycle
repeats twice per whole indicator rotation. The whole knob rotation
is not a day - it is equal to two defrost intervals or 20 hours on mine.

Loading Image...

The clockwork motor is 3 watts, and the gear reduction train is what
raises the torque to a high enough level to actuate the snap-action
cam. The switch must fall rapidly. The cam plastic must have a sharp
edge, or the switch contacts could be burned. It is because of
some of these design necessities that the torque level involved
is excessive, and you can hear some "hum" from the motor as it
struggles with its diminutive load.

Paul
John Rumm
2021-10-12 10:32:55 UTC
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Post by Gib Bogle
Sorry to belabour this issue.
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on the second row. The top one is $93, the other is $45. You can easily see that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is black not white, is otherwise identical as far as I can see. The knob is shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it doesn't touch anything as it turns.
It looks like the more expensive version is an OEM part, and the other a
generic replacement.

It also looks like the knob is a separate part - so can you remove it on
yours? If so you may be able to re-apply it to the generic version.

Having said that, if you don't need to interact with it, and it is not
connected to anything, it sounds like you don't need it anyway.
--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Gib Bogle
2021-10-12 18:52:37 UTC
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Post by John Rumm
Post by Gib Bogle
Sorry to belabour this issue.
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on the second row. The top one is $93, the other is $45. You can easily see that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is black not white, is otherwise identical as far as I can see. The knob is shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it doesn't touch anything as it turns.
It looks like the more expensive version is an OEM part, and the other a
generic replacement.
It also looks like the knob is a separate part - so can you remove it on
yours? If so you may be able to re-apply it to the generic version.
Having said that, if you don't need to interact with it, and it is not
connected to anything, it sounds like you don't need it anyway.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Thanks Paul and John. Very helpful info, Paul.
What puzzles me still is the function of the two cams.
I have decided that since the cams do not contact anything on my fridge they can be ignored, as John says.
The knob doesn't want to come off on mine - I didn't want to apply too much force.
The markings on the two versions of the timer at that supplier are identical - both Invensys - so I don't think one is generic. It looks more like a pricing screwup at the supplier.
Anyway, I found another supplier with the same (or almost the same) timer as the $93 one for $45, and I've ordered the timer and thermostat from there. They say delivery will take 5-10 days because of the pandemic. In the meantime our power bill will take a hit, because now the fridge seems to be running continuously.
Paul
2021-10-12 19:29:18 UTC
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Post by Gib Bogle
In the meantime our power bill will take a hit, because now the fridge seems to be running continuously.
That's true, but what you have to worry about more,
is whether that's good for the compressor or not.

Mine seemed to be traceable to the thermostat, which
had drifted out, weeks before, and took some fiddling
with the knob to get it to work. And after a while,
it would no longer stop.

What happened next, is it seemed the "cooling effort"
was reduced, suggesting maybe a gas leak. Perhaps at
the point I put it out of its misery, it was only
half filled. So on the one hand, the thermostat was
kaput, but on the other hand, the constant operation
of the compressor, somehow led to the lost of
refrigerant. I was expecting to find refrigerant
oil somewhere, but did not find anything like that
on the floor.

Once the fridge was put out of its misery, I put the
milk in a car cooler that has a Peltier solid state
cooling element in it. This runs off 12V @ 4A, and
I used a PC ATX supply for the +12V. That managed
to keep the inside of the picnic cooler at 2C for
over a week, running off ~50W of power. But I could
not put too much refrigerator content in there, just
the barest necessities.

Normally, those coolers aren't all that great, but by putting
it in the cool basement, the delta_T it managed to develop
was perfect for milk.

Peltier coolers are horribly inefficient, so before
you ask why refrigerators don't use them, it would
take kilowatts to do a good job. You can get frost
buildup on a Peltier, at around 20 amps of current
flow, but to build a refrigerator, you'd need multiple
of those. It has the advantage of moving heat, with
no moving parts. But there would be heatsinks
(a heatsink on the hot side, a heatsink on the cold side),
and to be useful, you put fans next to the heatsinks
to move the respective thermals away from the device.
The fans make a hell of a noise, while the part moving
the heat, does not.

Paul
Dave W
2021-10-12 22:19:19 UTC
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Post by Paul
Peltier coolers are horribly inefficient, so before
you ask why refrigerators don't use them, it would
take kilowatts to do a good job. You can get frost
buildup on a Peltier, at around 20 amps of current
flow, but to build a refrigerator, you'd need multiple
of those. It has the advantage of moving heat, with
no moving parts. But there would be heatsinks
(a heatsink on the hot side, a heatsink on the cold side),
and to be useful, you put fans next to the heatsinks
to move the respective thermals away from the device.
The fans make a hell of a noise, while the part moving
the heat, does not.
Paul
I would think that if you put a ginormous heatsink on it you wouldn't
need a fan.
Paul
2021-10-13 10:04:14 UTC
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Post by Dave W
Post by Paul
Peltier coolers are horribly inefficient, so before
you ask why refrigerators don't use them, it would
take kilowatts to do a good job. You can get frost
buildup on a Peltier, at around 20 amps of current
flow, but to build a refrigerator, you'd need multiple
of those. It has the advantage of moving heat, with
no moving parts. But there would be heatsinks
(a heatsink on the hot side, a heatsink on the cold side),
and to be useful, you put fans next to the heatsinks
to move the respective thermals away from the device.
The fans make a hell of a noise, while the part moving
the heat, does not.
Paul
I would think that if you put a ginormous heatsink on it you wouldn't
need a fan.
I think we'd need to see if anyone has built such a fridge
first, and have a look at their distribution scheme. And see
how they balanced the tradeoffs.

If you use fins, then heatpipes are sure to follow. A
heatpipe ensures you get the value from the fins. You can't
make a fin infinitely long, because the heat doesn't want to
travel to the fin end. So what they do instead, is lace
the fins together, at specific lengths, with heatpipes, and
the heatpipe provides excellent transport for the heat.
The fin then dissipates it.

This Zalman TNN500F computer case, is totally convection cooled.
The sides of the case, are giant heatsinks with fins. The heatpipes
dump their heat, into the aluminium of the sides.

Loading Image...

https://www.quietpc.com/tnn500af

That's one of the more ambitions attempts to handle heat.
The upper limit there is 400W, and reasonable limits might
be only about 200W of goods inside. A 95W CPU and a 100W
video card maybe. But to be honest, there's room in designs
like that, for *at least* one fan strategically placed.
Because many electronics items make assumptions that
some amount of forced cooling is present, and if you
ignore such assumptions, tiny components may overheat.

Paul
Gib Bogle
2021-10-13 20:16:29 UTC
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Post by Paul
Post by Gib Bogle
In the meantime our power bill will take a hit, because now the fridge seems to be running continuously.
That's true, but what you have to worry about more,
is whether that's good for the compressor or not.
Although the supplier said "5 - 10 days for delivery", the parts arrived the next day. I installed them and all seems to be working well - the fridge is cycling normally now.
The timer I got is not the one I ordered. This one is Paragon (same brand as the one I've removed) not Invensys, and although the one I ordered had the knob with 2 cams (which I don't understand) this one has a simple shaft with a notch. The shaft is shorter than the replaced one, and no longer stands proud of the hole, as it previously did. This means it would be hard to change manually, but I have no idea why anyone would want to rotate it, except for testing purposes I suppose. The timer has written on is "6 hours, 25 minutes".
The fridge should be good for another 20 years. A successful repair.
Thanks again for all your help, Paul. I now understand how my fridge works, and in a pinch I could get a job as a fridge repairman. :)
Brian
2021-10-12 19:03:42 UTC
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Post by Gib Bogle
Sorry to belabour this issue.
I have located a source of a timer with the same model number as mine,
1415435. The odd thing is that the shop has two timers with this model
https://www.homeappliancesonline.co.nz/results.html?q=westinghouse+defrost+timer
One is the third from the left on the top row, the other is the first on
the second row. The top one is $93, the other is $45. You can easily
see that everything about them is the same except for the knob.
"Which one look like yours you need to buy that , that grey knob is there for a purpose ."
In fact mine is by a different manufacturer (Paragon not Invensys), is
black not white, is otherwise identical as far as I can see. The knob is
shaped like the one on the $93 timer, with the two cams.
Does the knob really have a purpose? It is clear that on my fridge it
doesn't touch anything as it turns.
On the one we had, there wasn’t a proper knob just what looked like the
plastic shaft of a volume control, although the end was notched. You could
turn it, not that we did, I remember the repair main rotating it when
trying to figure out the problem.
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