urgent

[A_Ahed]

Dear Friends
It is a pleasure if u can be of any help :
In some DX air conditioning systems using R134 we face a problem :
During operation oil is discharged from crank case and then the compressor jams . In reciever sight glass there is thick layer of oil (8 - 10 mm) .
We came 2 conclusion that the reason is :
1-Using fake oil or refrigerant ?
2-As we had the compressors repaired, newly installed oil rings are not working properly so piston sucks oil into chamber and discharges it, as it happens in reciprocating engines causing oil to be burnt.

[paul_h]

Is this a newy designed system, or a retrofit of an old r12 air con plant?
If its a new system is the system designed correctly to allow oil return?
If it's an old retrofit, then obviously the design is OK, but what oil are you using, how many oil changes did you do?

[sylvester]

please note: oil used in in 134a is different from r12

[A_Ahed]

With so many thanks.
Yeap .It is a retrofit cycle but all the procedure in order to change the system has been done correctly.
Even the oil has been selected appropriately(poly ester)
But there is something u should know :
Compressor , Evaporator and condensor are on the same level ( Packaged system )

[Gary]

With so many thanks.
Yeap .It is a retrofit cycle but all the procedure in order to change the system has been done correctly.
Even the oil has been selected appropriately(poly ester)
But there is something u should know :
Compressor , Evaporator and condensor are on the same level ( Packaged system )

What was the original refrigerant? Did you change the TXV?

[A_Ahed]

Hi
The original refrigerant was R 12 and we had the TXV changed.

[vadivelan]

Did you check the cranckcase heater functioning? this seems to be related to flooded start situation. Do you have the pump down cycle?