AC compressor oil consumption

[sha3rawy]

Hi,

I have AC unit of 80 tons capacity with aworking compressor w-type (carrier) it has been retrofited to R-134a,using synthetic poloyol ester oil as a lubricant,I know that the oil may be transfered through the system as amist with the refrigerant. may concern is to know the actual oil level in the compressor.

I would like to know if there is a specific procedures to be sure that the oil that goes through the system is returned back to the compressor.
and also,

what is the indications for oil condensation at any place through the system?

Thanks.

 

[MintJulep]

A few hours of operation at a reasonably steady state should fill up any oil traps in the system.

As that happens you'll see the oil level fall in the compressor. When it stops falling, top the oil back up and watch it for another few hours. It should stay pretty level.

 

[imok2]

With the unit running, inspect the oil level through the sight glass at the side of the compressor If oil can be seen in the glass, then the level is correct, if oil cannot be seen, then oil must be added The oil will very between 1/4 and 3/4 sight glass depending on loading.

 

[DrRTU]

Proper oil return needs to be evaluated over the complete operational range. In a system with large coil surface area, unloading or HGBP to the compressor may log oil in the evaporator at low loads. With the Carlyle pump, monitor the sump level at the site glass. It is generally accepted to run about 1/3 on the glass. At 80 tons, you most likely have numerous compressors connected with an equalizing tube.