As in my previous post the thermostat inside our 4 year old Hotpoint
freezer has failed and isn't replaceable due to being buried in the foam
lining of the casing.

Ive bought this Inkbird temp controller
https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
which happily turns the power to the freezer off at -18 degrees and on
again at -16.

However when the temp controller restores power at -16 the freezer
doesn't restart! Yet it did restart whilst using the temporary plug in
timer set to off/on every 30 minutes.

What could the problem be?

Mike

On 11/08/2023 09:38, Mike Rogers wrote:
>
>
> As in my previous post the thermostat inside our 4 year old Hotpoint
> freezer has failed and isn't replaceable due to being buried in the foam
> lining of the casing.
>
> Ive bought this Inkbird temp controller
> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
> which happily turns the power to the freezer off at -18 degrees and on
> again at -16.
>
> However when the temp controller restores power at -16 the freezer
> doesn't restart! Yet it did restart whilst using the temporary plug in
> timer set to off/on every 30 minutes.
>
> What could the problem be?

How long after the thermostat turns off does it then command for cooling?

I'm wondering if the motor thermal cutout is operating from too short a
time being turned off before restarting the motor.

I might set the hysteresis to be -22C and -17C or similar. To ensure a
longer 'off' time.

Can you also plug in a lamp to indicate when the motor should be running?

On 11/08/2023 09:38, Mike Rogers wrote:
>
>
> As in my previous post the thermostat inside our 4 year old Hotpoint
> freezer has failed and isn't replaceable due to being buried in the foam
> lining of the casing.
>
> Ive bought this Inkbird temp controller
> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
> which happily turns the power to the freezer off at -18 degrees and on
> again at -16.
>
> However when the temp controller restores power at -16 the freezer
> doesn't restart! Yet it did restart whilst using the temporary plug in
> timer set to off/on every 30 minutes.
>
> What could the problem be?
>

if built-in thermostat wasn't bypassed it might be the self-healing
intermittently with maximum perversity

--
Robin
reply-to address is (intended to be) valid

On 11/08/2023 10:49, Fredxx wrote:
> On 11/08/2023 09:38, Mike Rogers wrote:
>>
>>
>> As in my previous post the thermostat inside our 4 year old Hotpoint
>> freezer has failed and isn't replaceable due to being buried in the foam
>> lining of the casing.
>>
>> Ive bought this Inkbird temp controller
>> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
>> which happily turns the power to the freezer off at -18 degrees and on
>> again at -16.
>>
>> However when the temp controller restores power at -16 the freezer
>> doesn't restart! Yet it did restart whilst using the temporary plug in
>> timer set to off/on every 30 minutes.
>>
>> What could the problem be?
>
> How long after the thermostat turns off does it then command for cooling?
>
> I'm wondering if the motor thermal cutout is operating from too short a
> time being turned off before restarting the motor.
>
> I might set the hysteresis to be -22C and -17C or similar. To ensure a
> longer 'off' time.
>
> Can you also plug in a lamp to indicate when the motor should be running?

+1

If the lamp doesn't work, try setting it up in reverse as a thermostat
for heating, by connecting a heater to the "heating" socket rather than
using it a freezer stat and plugging in to the "cooling" socket. If
heating works, it would suggest that the cooling side is faulty in some way.

--

Jeff

On 8/11/2023 4:38 AM, Mike Rogers wrote:
>
>
> As in my previous post the thermostat inside our 4 year old Hotpoint freezer has failed and isn't replaceable due to being buried in the foam lining of the casing.
>
> Ive bought this Inkbird temp controller
> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
> which happily turns the power to the freezer off at -18 degrees and on again at -16.
>
> However when the temp controller restores power at -16 the freezer doesn't restart! Yet it did restart whilst using the temporary plug in timer set to off/on every 30 minutes.
>
> What could the problem be?
>
> Mike

"[Heating Cooling Dual Output & Delay Protection]
Dual relay output to connect in a position with refrigeration
and heating systems at the same time. Heating / Cooling differential
function can be set to protect separately for cooling and heating for
temperature control of violent change.

Also, compressor delay protection for compressor control." <=== what does this mean ???

*******

Refrigerant compressors come in two types. Some compressors can tolerate
a "slug of liquid" on the suction side. Other compressors might be
damaged by the ingestion of liquid (such as a piston compressor).
We use a lot of scroll compressors instead, because a scroll compressor
can tolerate a small amount of liquid in the line.

If you delay the switch-on of a compressor, right after it switches off,
this gives time for liquid in the suction side to boil and turn back
into a gas. Reducing the chance that an "intolerant" compressor will
be presented with that slug of liquid.

So even when the temperature criterion is met, the unit may delay turn-on,
for the number of minutes you programmed it for.

Paul

On Fri, 11 Aug 2023 06:12:36 -0400, Paul wrote:

> Refrigerant compressors come in two types. Some compressors can tolerate
> a "slug of liquid" on the suction side. Other compressors might be
> damaged by the ingestion of liquid (such as a piston compressor).
> We use a lot of scroll compressors instead, because a scroll compressor
> can tolerate a small amount of liquid in the line.
>
> If you delay the switch-on of a compressor, right after it switches off,
> this gives time for liquid in the suction side to boil and turn back
> into a gas. Reducing the chance that an "intolerant" compressor will be
> presented with that slug of liquid.

That's answered a question I've had for a few days. I have just started
using a portable air conditioner, and they tell you not to turn it on for
three minutes after turning it off (in fact, it has a timer circuit to
prevent that).

Now I know why.

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

Historesis in the thermostat? Most thermostats have a different on and off
value depending on whether the temp is falling or rising, otherwise it would
be cycling on and off very fast.
You can show this on a fan heater quite clearly, as the knob has to be
turned back further to make it come on, than it does for it to go off.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Mike Rogers" <mike@mattishall.org.uk> wrote in message
news:C62cnYMKvsYXbkj5nZ2dnZfqn_ednZ2d@brightview.co.uk...
>
>
> As in my previous post the thermostat inside our 4 year old Hotpoint
> freezer has failed and isn't replaceable due to being buried in the foam
> lining of the casing.
>
> Ive bought this Inkbird temp controller
> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
> which happily turns the power to the freezer off at -18 degrees and on
> again at -16.
>
> However when the temp controller restores power at -16 the freezer doesn't
> restart! Yet it did restart whilst using the temporary plug in timer set
> to off/on every 30 minutes.
>
> What could the problem be?
>
> Mike

Are you sure its actually turning it on though? Also of course there could
well be another thermostat somewhere else.
It hold work though I think expecting it to be as accurate as 2 degrees is
a bit too much.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Fredxx" <fredxx@spam.invalid> wrote in message
news:ub506h$pug2$2@dont-email.me...
> On 11/08/2023 09:38, Mike Rogers wrote:
>>
>>
>> As in my previous post the thermostat inside our 4 year old Hotpoint
>> freezer has failed and isn't replaceable due to being buried in the foam
>> lining of the casing.
>>
>> Ive bought this Inkbird temp controller
>> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
>> which happily turns the power to the freezer off at -18 degrees and on
>> again at -16.
>>
>> However when the temp controller restores power at -16 the freezer
>> doesn't restart! Yet it did restart whilst using the temporary plug in
>> timer set to off/on every 30 minutes.
>>
>> What could the problem be?
>
> How long after the thermostat turns off does it then command for cooling?
>
> I'm wondering if the motor thermal cutout is operating from too short a
> time being turned off before restarting the motor.
>
> I might set the hysteresis to be -22C and -17C or similar. To ensure a
> longer 'off' time.
>
> Can you also plug in a lamp to indicate when the motor should be running?
>

On 11/08/2023 09:38, Mike Rogers wrote:
>
>
> As in my previous post the thermostat inside our 4 year old Hotpoint
> freezer has failed and isn't replaceable due to being buried in the foam
> lining of the casing.
>
> Ive bought this Inkbird temp controller
> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
> which happily turns the power to the freezer off at -18 degrees and on
> again at -16.
>
> However when the temp controller restores power at -16 the freezer
> doesn't restart! Yet it did restart whilst using the temporary plug in
> timer set to off/on every 30 minutes.
>
> What could the problem be?
>
> Mike

Are you just testing by, say, putting the probe inside the freezer to
see at what temperature the compressor goes off and then removing the
probe to raise the temperature quickly to see when it comes on again or
are you running it as you would normally? The instructions indicate
that there is a compressor delay of up to 10 minutes if you try and
cycle between the temperatures too fast. The timer (up to 10 minutes)
is initialised when cooling stops.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 11/08/2023 09:38, Mike Rogers wrote:
>
>
> As in my previous post the thermostat inside our 4 year old Hotpoint
> freezer has failed and isn't replaceable due to being buried in the foam
> lining of the casing.
>
> Ive bought this Inkbird temp controller
> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
> which happily turns the power to the freezer off at -18 degrees and on
> again at -16.
>
> However when the temp controller restores power at -16 the freezer
> doesn't restart! Yet it did restart whilst using the temporary plug in
> timer set to off/on every 30 minutes.
>
> What could the problem be?
>
> Mike

Thanks for all the suggestions.

It has provision for a startup delay, I had that set to two minutes, Ive
increased it to four and its now working fine, currently set to switch
off at -18c then on again after a drop of 2.5c.

I'm now playing around with different positions with the sensor for best
overall control.

Mike

On 15/08/2023 09:23, Mike Rogers wrote:
> On 11/08/2023 09:38, Mike Rogers wrote:
>>
>>
>> As in my previous post the thermostat inside our 4 year old Hotpoint
>> freezer has failed and isn't replaceable due to being buried in the
>> foam lining of the casing.
>>
>> Ive bought this Inkbird temp controller
>> https://www.amazon.co.uk/Inkbird-ITC-308UK-Temperature-Controller-Thermostats/dp/B01E74TEPG
>> which happily turns the power to the freezer off at -18 degrees and on
>> again at -16.
>>
>> However when the temp controller restores power at -16 the freezer
>> doesn't restart! Yet it did restart whilst using the temporary plug in
>> timer set to off/on every 30 minutes.
>>
>> What could the problem be?
>>
>> Mike
>
>
> Thanks for all the suggestions.
>
> It has provision for a startup delay, I had that set to two minutes, Ive
> increased it to four and its now working fine, currently set to switch
> off at -18c then on again after a drop of 2.5c.
>
> I'm now playing around with different positions with the sensor for best
> overall control.
>

The measured temperature rising from -18 to -16 in less than 4 minutes
suggests it was measuring the temperature of free air. FWIW one sensor
position known to avoid that is inside a bag of petit pois.

--
Robin
reply-to address is (intended to be) valid

Robin <rbw@outlook.com> wrote:
> The measured temperature rising from -18 to -16 in less than 4 minutes
> suggests it was measuring the temperature of free air. FWIW one sensor
> position known to avoid that is inside a bag of petit pois.

Isn't free air what you want? The bag of petit pois is likely to stay cold
for a lot longer, by which time the croissant on the next shelf has already
gone soft. In other words, when you open the door and let warm air in, you
want the freezer to fire up to cool the air, you don't want the air to be
cooled by warming up items in the freezer.

Theo

On 15/08/2023 12:27, Theo wrote:
> Robin <rbw@outlook.com> wrote:
>> The measured temperature rising from -18 to -16 in less than 4 minutes
>> suggests it was measuring the temperature of free air. FWIW one sensor
>> position known to avoid that is inside a bag of petit pois.
>
> Isn't free air what you want? The bag of petit pois is likely to stay cold
> for a lot longer, by which time the croissant on the next shelf has already
> gone soft. In other words, when you open the door and let warm air in, you
> want the freezer to fire up to cool the air, you don't want the air to be
> cooled by warming up items in the freezer.
>
> Theo

I'm with Robin. Sensor in free air has been working well for nearly two
weeks now :-)

Mike