Liebert DX condenser fans

[dschultz307]

I have two 20 Liebert DX air cooled condensers that I observe different discharge airflow patterns on the fans.

I observe the difference on the two constant speed fans.

One fan discharges the air straight up; the other tends to blow air off to the side with a lot of dead space at the center.

The surface of the coils do not appear to be clogged but these coils are about 4-5 inches thick.

The fan with the "sideways" air flow is also the one that gets the most year 'round runtime in my climate.

Thoughts? Very clogged coil? I also have two brand new condensers with out this issue.


What is the best way to deep clean these coils?

We have experienced high pressure trips when it is over 95-100 degrees ODT. At about 85 degrees ODT the head pressure was 260 on one circuit and 270 on the other; Semi-Hermetic compressors, no unloaders. Liebert book says high pressure cutout is 360.

Thanks.

[hands]

Make sure the fan blade is at the correct height and clean the coils with a Non-Acid coil cleaner.

[frio]

is the rotation correct on the one with sideways air flow?

[dschultz307]

I believe the rotation is correct.

I will double check Monday.

Thanks.

[noljohn]

I think it's a dirty coil. Air is sucked in around center of fan blade and discharged out around the outside of fan blade.

[GoColts]

First check for a dirty coil, then take amp draws on the motor in question and compair it too the the other motor. Has it been changed out before? You may have to adjust the height of the fan blade a little. :cheers:

[HvacCraftsman]

1. I would Agree with GoColt start with the amp draw on the 2 Cond fans to make sure one isnt just free wheeling.

2. Liebert has reccomended for cleaning to be done from starting at the top of the condenser pushing water/cleaner down towards the roof/ground.

3.Do you have Discharge Air temp with each of the fans matching closely?