How to determine the refrigerator compressor run time?

[alexan_sim]

how long should refrigerator run

Does anyone know how long can the refrigerator compressor run?
additionly, in the compressor data sheet, i can not find any information about compressor runtime.
So, how to determine the compressor runtime in this case?

 

[melc]

refrigerator compressor runs constantly

The compressor runs as long the thermostat stops it.
This time is not a compresor characteristic but depends by the fridge chamber volume, thermal isolation (and frozen water thickness on the inside walls) and outside world temperature. As good will be the isolation and as low the room temperature (where the fridge lives) as short time will run the compresor. Easy.
The longest time which a good compressor could run is forever. I've saw one running continously from about three years...

 

[alexan_sim]

refrigerator run time

in my case, i want to control the compressor using my control circuit. So does the compressor need the specified time to on and off?

i actach the data sheet here for u for reference. (). Anyway i can not find any information about the compressor run time.
But i found out that the compressor can run at max ambient temperature about 40 C.
Should i use it as a reference point for ON/Off time of the compressor?

i worry that if i turn the compressor running for longer time then it would be spoiled
So, what is the best solution to determine the On/Off time?

Thanks in advance!

 

[House_Cat]

refrigerator running time

melc tried to tell you in his post above that there is no time limit on compressor operation. The length of time that a refrigeration compressor runs is dependent on the temperature of the space being cooled. A temperature sensor provides that information to the compressor control circuit.

There are also safety switches built into a refrigeration control circuit to protect the compressor from liquid refrigerant feedback which can destroy the pump vanes (since the pump is only designed to pump gaseous refrigerant), and loss of refrigerant which can destroy the pump from loss of lubrication and cooling. Those protective switches are usually pressure sensors located at the appropriate points in the refrigeration cooling loop.

Once again - refrigeration compressor operation is NOT a timed operation. It is based on pressures and temperatures in the cooling loop.

 

[alexan_sim]

average refrigerator run time

Thanks House_Cat and melc

let's say the compressor can run at max ambient temperature about 40 C. If i attach the sensor to the compressor case and the sensor reads the temperature until 40 C, then in this case, should i switch off the compressor?

 

[House_Cat]

how long should a refrigerator run

You would never put the compressor in the same space that you are cooling. The compressor would be located near the inlet to the condensor coils. Hot gaseous refrigerant is pumped by the compressor into the condensor. Heat exchange allows the gas to cool and condense. The condensed liquid refrigerant then flows into the evaporator coil through a Thermostatic Expansion Valve (TXV) that controls the flow to match the rate of evaporation in the cooling coil.

The temperature sensor that I was talking about is a temperature sensor in the COLD space. That sensor would be used to turn off the refrigeration compressor when the COLD space reached the desired temperature. The compressor would never be located in the cold space, so you wouldn't attach the sensor to the compressor.

Very few systems monitor the temperature of the compressor - it is going to be hot because it is compressing an already hot gas, and the heat of compression is added to the gas temperature. The compressor is designed to run hot. That is why it is located outside the house for a home air conditioning system, or under the box in the open air for home refrigerators.

A refrigeration compressor isn't controlled by the temperature or run-time of the compressor. It is controlled by how cool the space is in which the evaporator coil is located. The compressor runs however long it needs to, and however hot it needs to, to try and reach the cooling goal. If you leave the door to a refrigerator open, the compressor will run until it wears out, or the kitchen reaches the set temperature of the refrigerator.

The basic refrigeration cycle is explained in the two following urls:
**broken link removed**
and
http://en.wikibooks.org/wiki/Wikijunior_How_Things_Work/Refrigerator

 

[hr_rezaee]

how long should a refrigerator run for

hi
you can run te compressor until its temperature is not over than a critical temp.
if the temp. is over than a critical temp., overload in the compressor (or on it) acts as fuse.
regards

 

[xxargs]

refrigerator compressor hot

The compressor runs as long the thermostat stops it.
This time is not a compresor characteristic but depends by the fridge chamber volume, thermal isolation (and frozen water thickness on the inside walls) and outside world temperature. As good will be the isolation and as low the room temperature (where the fridge lives) as short time will run the compresor. Easy.
The longest time which a good compressor could run is forever. I've saw one running continously from about three years...

Most old fridge or freeze-box going around 50% of time to make low as possible temperature swing inside the chamber.

I know 2 freeze-box going > 43 years without any repairs...


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Here down is possible intresting forums above self build cooling systems (primary for cooling CPU - but problem is same in other usings), is parts in advanced answers ie. select refrigerant, length of capillar tube, filling volyme, optimize for low temperature or transport maximum amount of heating, how to get refrigerant (is easy to get for anybody in some contrys and near impossible to get in other contrys without cooling certificate, depend of regulations... ... but same hard regulated liquid is easy to get in canned air in same contry... etc. etc.

**broken link removed**