Lowering maximum temperature

[puansingye]

I got a freezer that can go to maximum -15 degrees now.

Would it be able to go to -20 degrees if I change the thermostat max settings?

[mbc]

Hi
Main thing is that .
But to give you right answer need to know more about your system
Type of refrigerant and compressor.

[Rob White]

.

Minus 15 for a freezer is unusual.
Minus 20 is more like the normal.

Are you sure this is a freezer?

Rob

.

[Brian_UK]

Did it go to lower temperatures before now?

What is ambient temperature around the freezer?

Has anything changed since first installation?

Is compressor running still at -15 or is thermostat still calling for compressor?

[puansingye]

No, it did not go below -15.

Compressor model: L76CZ1
Refrigerant: R134A

Understand that R134A is not able to go to lower temperature. Must be R404A, correct?

[Rob White]

.

If it is this comp then Minus 23 evap temp equates to about minus 13 case temp.

https://www.womacool.com/productinfo/284992.html


So if it is at minus 15 then you are at the limits of the comp.

Rob


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[skarrs71]

On 134a comp would need to run in vac on suction to achieve -20, which is never a good idea unless it is a special design, for low temp should be 448A, 449A, 407A or F, but on a 134a system may well require different pipework sizing, would probably be better to replace with a properly specified system.