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Freezer not getting cold enough

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Sonnyboy

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a system I set up over a year ago with help from this forum has been powering a small freezer without issue…until last week. After losing a bunch of food, I discovered the freezer, a small 3 cu ft model wasn’t reaching 0.

I purchased a new freezer in a panic only to discover that the old one worked when plugged into the house (grid) socket and the new one also struggles to get to zero, now hovering around 11.

The freezer is plugged into a Novopal 2000w inverter with an inkbird wired into it. The inkbird is supposed to turn on the inverter only when the freezer needs to turn on.

I am not sure what the problem could be as all the components seem to be working. Where should I begin to test things? Thank you!
 
You may have issue with defrosting. A temp controller only works on inside temperature and would not activate for defrosting demand.

You may never be getting a defrost cycle or getting defrost cycle upon every power restoration. Both situations can result in lack of proper cooling.

Some refrigerators will assume they need to initiate a defrost cycle upon power restoration after a power loss. This would cause any inverter standby shutdown controller to trigger a new defrost cycle shortly after every activate power on. Other extreme is defrost timer waits 14-18 hours after sustained power restoration to trigger a defrost cycle. Since it never gets sustained AC input power for 14-18 hours, it never defrosts, ice builds up and blocks evaporator reducing cooling.

Normally a refrig runs a defrost cycle every 14-18 hours.
 
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RCinFLA said:
You may have issue with defrosting. A temp controller only works on inside temperature and would not activate for defrosting demand.

You may never be getting a defrost cycle or getting defrost cycle upon every power restoration. Both situations can result in lack of proper cooling.

Some refrigerators will assume they need to initiate a defrost cycle upon power restoration after a power loss. This would cause any inverter standby shutdown controller to trigger a new defrost cycle shortly after every activate power on. Other extreme is defrost timer waits 14-18 hours after sustained power restoration to trigger a defrost cycle.

Normally a refrig runs a defrost cycle every 14-18 hours.
Click to expand...
Right, but the same problem with a brand new freezer? Should be reaching subzero no problem.
 
Sonnyboy said:
a system I set up over a year ago with help from this forum has been powering a small freezer without issue…until last week. After losing a bunch of food, I discovered the freezer, a small 3 cu ft model wasn’t reaching 0.

I purchased a new freezer in a panic only to discover that the old one worked when plugged into the house (grid) socket and the new one also struggles to get to zero, now hovering around 11.

The freezer is plugged into a Novopal 2000w inverter with an inkbird wired into it. The inkbird is supposed to turn on the inverter only when the freezer needs to turn on.

I am not sure what the problem could be as all the components seem to be working. Where should I begin to test things? Thank you!
Click to expand...
I would start with a voltage and frequency check of the inverter output. Then see what happens when the freezer is running and it loads up the inverter.

Sounds like the compressor is struggling.

A kill-a-watt meter is great for this type of troubleshooting.

Kill-a-watt
 
Questions -
1. what is the rated wattage of the freezer - take a picture of the identification sticker - it should tell both average and max startup wattage needed.
2. what is the wattage of the inverter and what brand/model is it. i.e. LF can do startup current more than HF ones.

A typical frost free deep freeze just runs 55watts or so but 250watts to start the compressor.
BUT - the defrost circuit will run 300+ watts constantly either off a timer or a sensor for frost. The wattage ratings on your freezer may be very different than this example.

I looked at your freeze build thread and it seems you have some voodoo going on with a temp controller and other stuff besides a pure inverter -> freezer hookup?

Can you use drawio and make a diagram of your setup? drawio is free and takes about 10 minutes to learn to use. Youtube videos are plentiful, but you only need the basics.

For devices you can just screen cap and past right in, then connect with lines for the wires.
 
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robbob2112 said:
Questions -
1. what is the rated wattage of the freezer - take a picture of the identification sticker - it should tell both average and max startup wattage needed.
2. what is the wattage of the inverter and what brand/model is it. i.e. LF can do startup current more than HF ones.

A typical frost free deep freeze just runs 55watts or so but 250watts to start the compressor.
BUT - the defrost circuit will run 300+ watts constantly either off a timer or a sensor for frost. The wattage ratings on your freezer may be very different than this example.

I looked at your freeze build thread and it seems you have some voodoo going on with a temp controller and other stuff besides a pure inverter -> freezer hookup?

Can you use drawio and make a diagram of your setup? drawio is free and takes about 10 minutes to learn to use. Youtube videos are plentiful, but you only need the basics.

For devices you can just screen cap and past right in, then connect with lines for the wires.
Click to expand...
Attached is a photo of the setup and the label on the freezer. The freezer is NOT the issue. As I have stated, it runs fine when plugged in inside the house. It is either the inverter or Inkbird or both and I am not sure how to diagnose them. I will look into a watt meter or if there is some way to do this with a multimeter from the unused outlets. On the attached photo of the setup, the blue(albeit faint) circle is where the inkbird was wired into the inverter on off switch. The white is the power working to the inkbird.
 

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Sonnyboy said:
It is either the inverter or Inkbird
Click to expand...

As I suggested earlier, bypass the inkbird. I'll bet that is the issue. I have several of them and you have to set the temp differential properly. In other words if you set it to turn on if the temp goes above a certain temperature, you have to make sure it stays on until the desired low temperature is achieved. Of course, make sure you are using the correct relay contacts. I have also had the relay contacts go bad, they may not be able to handle that compressor startup long term. If controlling heavy loads, I use the inkbird relay to turn on a heavy duty one.
Sonnyboy said:
I am not sure how to diagnose them.
Click to expand...

Just told you above, bypass the inkbird for a while.
 
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I can bypass the inkbird by switching the inverter to ON…then it is always on. That does in fact get it down to -3(as of now). What are the correct relay contacts you mentioned? On the inkbird I was only using the TS to set the temp at zero and the DS to turn on the inverter/freezer when the temp rises five degrees above 0. Am I missing another setting ?
 
Sonnyboy said:
Am I missing another setting ?
Click to expand...

I'm not near my manuals and stuff. Try using some ice water and set it the temp accordingly to test with that for proper operation

What power source are you using for the inkbird (they come in different versions).
 
seneysolar said:
I would start with a voltage and frequency check of the inverter output. Then see what happens when the freezer is running and it loads up the inverter.

Sounds like the compressor is struggling.

A kill-a-watt meter is great for this type of troubleshooting.

Kill-a-watt
Click to expand...
Multimeter reads 110v in n the outlets of the inverter when it is in use
 
Texas-Mark said:
I'm not near my manuals and stuff. Try using some ice water and set it the temp accordingly to test with that for proper operation

What power source are you using for the inkbird (they come in different versions).
Click to expand...
It is powered by my solar panels. It is wired to a fuse box (2amp fuse) and a neg bus bar.
 
Sonnyboy said:
It is powered by my solar panels.
Click to expand...

No, what i meant was - what power source is used for the inkbird (120v or 12v or ??) They come in different versions. I ask because perhaps when the compressor kicks in, it causes the voltage to drop going to the inkbird and causes it to glitch.
 
Texas-Mark said:
No, what i meant was - what power source is used for the inkbird (120v or 12v or ??) They come in different versions. I ask because perhaps when the compressor kicks in, it causes the voltage to drop going to the inkbird and causes it to glitch.
Click to expand...
12 volt
 
Sonnyboy said:
12 volt
Click to expand...

So, perhaps the load when the compressor starts glitches the inkbird.

Still a lot of unanswered questions. Have you actually sat by the unit to see what it is doing? Is the compressor even starting? OI assume so, since you said it was "sort of cool". Next is to monitor the inkbird to see when it is actually turning on and off. And as I noted earlier, the relay in those things is not very heavy duty regardless of what they claim.
 
Texas-Mark said:
So, perhaps the load when the compressor starts glitches the inkbird.

Still a lot of unanswered questions. Have you actually sat by the unit to see what it is doing? Is the compressor even starting? OI assume so, since you said it was "sort of cool". Next is to monitor the inkbird to see when it is actually turning on and off. And as I noted earlier, the relay in those things is not very heavy duty regardless of what they claim.
Click to expand...
When switched to go through the Inkbird, it cools but at a markedly slow pace as compared with switching off the Inkbird. That said, I swapped the batteries out. The be I was using said it was fully charged but maybe that could be part of the problem. I will order another inkbird if this doesn’t solve it and report back. Would be great if there was some definitive test I could run on the inkbird.
 
Sonnyboy said:
When switched to go through the Inkbird, it cools but at a markedly slow pace as compared with switching off the Inkbird.
Click to expand...

Since the inkbird only controls a relay, and since you said it is cooling somewhat, it appears it is working. However, you still need to see what temperature it is actually turning off and on. I believe that is the differential setting. If it's set for only a couple of degrees (lets say 4), it will turn on at lets say 10 degrees, but it will turn back off at 6 degrees and never get down to 0 or less.
 
If the temperature differential is too close, you may be getting hot starts which further delay cooling.

Your contacts may be crapping out. This stuff is such junk.

I have found that freezers highly stratify temperature. Your probe may be in the wrong position.
 
efficientPV said:
If the temperature differential is too close, you may be getting hot starts which further delay cooling.
Click to expand...

This ^^ could likely be the problem.

The freezer is designed to have its own internal thermostat cycling the compressor, NOT some external jobbie.

On my Haier, if you unplug it while it is running, then immediately plug it in again, it won't start. It'll wait 5 - 10 minutes then fire the compressor. This is by design and is also the case for other fridges/freezers that I own.

Additionally, there is a 10 degree difference between stop/start with the internal temp. controls.

Of course this doesn't answer the question as to why it worked for some time before falling over. I agree with the other posters that the InkBird is at fault.
 
Why not just plug the freezer straight in to your inverter source and let it run it’s cycles naturally…as when you plug it into a grid source ……

it will then draw what it needs to draw to do what it supposed to do when it’s supposed to do it….

if it doesn’t work then, it’s broken…

if it works then somthing extra your doing is affecting it adversely …
Good luck…

J.
 
JRH said:
Why not just plug the freezer straight in to your inverter source and let it run it’s cycles naturally…as when you plug it into a grid source ……

it will then draw what it needs to draw to do what it supposed to do when it’s supposed to do it….

if it doesn’t work then, it’s broken…

if it works then somthing extra your doing is affecting it adversely …
Good luck…

J.
Click to expand...

And if idle power on the inverter is the issue spring for a better one with lower idle draw. Some in that size are as low as 10w or so
 
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