Carrier 19XR

[bunglebear]

Had a fault with one of these machines. The alert 162 is relating to high cooler approach which at near full load is around 8-10 degrees F (5-6 degrees C) the oil level looks low in the compressor as well. The skimmer line sight glass was clear. At part load 60% amps and 30% guide vanes the appraoch is much lower (1.3 degrees C or 2.5 degrees F) there is liquid flashing in the skimmer line sight glass and the alert is gone. I checked the resistance of the thermistors which seem OK. The flows are near enough, only marginally low. My deduction is that there is a refrigerant shortage, as at fuller load the liquid in the cooler is below the skimmer line, which leads to poor oil return (the level is lower). Another identical chiller runs mormal oil levels, and a 0.2 degree C appraoch, with flashing in the skimmer line.

Any other comments would be welcomed

Thanks

[poppop]

I would say your deduction is dead on. Rarely see these machines with more than a 2 degree f approach at full load.

[pete_d]

Originally Posted by bunglebear

Had a fault with one of these machines. The alert 162 is relating to high cooler approach which at near full load is around 8-10 degrees F (5-6 degrees C) the oil level looks low in the compressor as well. The skimmer line sight glass was clear. At part load 60% amps and 30% guide vanes the appraoch is much lower (1.3 degrees C or 2.5 degrees F) there is liquid flashing in the skimmer line sight glass and the alert is gone. I checked the resistance of the thermistors which seem OK. The flows are near enough, only marginally low. My deduction is that there is a refrigerant shortage, as at fuller load the liquid in the cooler is below the skimmer line, which leads to poor oil return (the level is lower). Another identical chiller runs mormal oil levels, and a 0.2 degree C appraoch, with flashing in the skimmer line.

Any other comments would be welcomed

Thanks

The float valve is stuck.

[consolidmech]

Is this a 19XRV

[carriermechanic]

Looks like you are low on ref. But it is not because you can't see anything in the skimmer line at full load. At full load the chiller gets oil return up through the suction elbow not the skimmer line. Normally if you are getting liquid through the skimmer line at full load than you are overcharged. But i would start with adding a little ref. when the chiller is running close to full load. If the approach does not start getting better then there might be another problem like a sticking float. We have had to replace several floats over the years because of a bad design. But the new design works.