questions

[jumanje13]

hi every body
here is my questions to my friends
first i need to know alot about pump down
and why it is a great opportunity to form liquid in suction line in freezing condition as cooling is less
last when you choose a reciver how much litre to 1 hp
thnx for help

[praveen]

pump down is the process to save refrigerant.Pump down done when indoor unit or piping repair fix issue is there.
i not understand ur liquid in suction line.
liquid in suction line will hurt compressor.

[monkey spanners]

Hi jumanji,

If you are asking about pumping down to work on a system then as Praveen says.

If you are asking about pumpdown as a means to control the condensing unit then it is done to prevent liquid migration when the system is off. The evaporator can fill with liquid when the system is off and will return as a slug when the system starts possibly damaging the compressor. If the compressor is in a colder space than the evaporator then liquid can condense in the compressor when its not running causing damage when it restarts. Pumpdown stops this happening. It can also make the wiring simpler with no need for a signal wire from the thermostat as the system is now controlled by the low pressure switch.

I don't know of any hp to litre reciever formula, most close coupled systems have a suitably size recieve already fitted on the condensing unit as supplied by the manufacturer.
If you are building a system up from component parts or it has long pipe runs then you will need to calculate the volume of refrigerant the system will hold and size accordingly.

Jon