Pump Down Procedure

[hamidpia]

Hello: While servicing low pressure side, I saw a machanic using pump down procedure as follows. 1. Closed HP valve on the discharge side of compressor
2. Unit was kept running for short while, with suction side valve open unit suction side pressure came down to 30psi (low pressure trip was set at 26psi). 3.Unit was stopped and Low pressure valve was closed after that. This way, he would collect refrigerant into condenser unit and thereafter he would work on the evaporator.
I just want to know is this a correct procedure, is there any gereral pump down procedure besides this.
Best regards

[kiwireeferman]

Hello: While servicing low pressure side, I saw a machanic using pump down procedure as follows. 1. Closed HP valve on the discharge side of compressor
2. Unit was kept running for short while, with suction side valve open unit suction side pressure came down to 30psi (low pressure trip was set at 26psi). 3.Unit was stopped and Low pressure valve was closed after that. This way, he would collect refrigerant into condenser unit and thereafter he would work on the evaporator.
I just want to know is this a correct procedure, is there any gereral pump down procedure besides this.
Best regards

I assume the HP valve you refer to is the outlet valve on the liquid receiver, not the discharge service valve on the compressor?

[icecube51]

it can be done this way,but make sure to come in the vacuum, watch the manifolds closely. if you want to do it that way, do it via the relays by manual command,otherwise when you start the system whit the indoor command its take to long before you can stop the system and may possible damage the compressor.:rolleyes:

when its not possible work whit a walkie talkie and a extra pair of hands , and ears.;)

Ice

[icecube51]

O, bey the way, you olso can invest in a recuparation device ( 1000,-€ ), an empty bottle , and a refrig scale (450,-€)
than you can work on the complete system whitout los of oil and refrig.
change the compressor oil, purge the tubes and clean them, install burn out filters, ......and so on.

think about it:cool:

Ice

[coolhibby1875]

there is something amiss if you close the discharge on the compressor it should cut out on hp strait away

[icecube51]

therefore we have Small screwdrivers,ho block the spring for doing so :p.

Ice

[Akram Hamza]

Hi,
you shoud be close the liquid resevaer valve (don't closed HP servece valve is v.dangeres )then operate the Compressor until suction presuer drop to 10PSI and then closed the suction servece valve.
Remark the low presure switch shoud be cancel.
Many Thanks.

[brianubaldo]

Hello: While servicing low pressure side, I saw a machanic using pump down procedure as follows. 1. Closed HP valve on the discharge side of compressor
2. Unit was kept running for short while, with suction side valve open unit suction side pressure came down to 30psi (low pressure trip was set at 26psi). 3.Unit was stopped and Low pressure valve was closed after that. This way, he would collect refrigerant into condenser unit and thereafter he would work on the evaporator.
I just want to know is this a correct procedure, is there any gereral pump down procedure besides this.
Best regards


TRY THIS ONE

[EX.1 IF YOU HAVE A LIQUID RECIEVER]
-first the unit must be operating
-do not close the high side service valve of the compressor.
-first close the access valve in the liquid reciever going to the evaporator..
-watch the pressure, then close the access valve in the reciever from the high side of the compressor "not the high side service valve of the compressor"
-all the liquid refrigerant go to your reciever

[EX.2 IF YOU DONT HAVE RECIEVER, BUT YOU CAN DO ONLY IN SPLIT A/C SYSTEM]
-first the unit must be operating
-close the discharge valve of the condensing unit
-watch the pressure, then close the suction valve in the condensing unit.. all the refrigerant is now in the condensing unit..