Centrifugal chiller

[fahood93]

how can centrifugal chiller compressor shaft brocken , is it possible by power fluctuation.

[sedgy]

hi fahood93 , have you striped it down yet?

[centrecipew]

Hi, Probably Excessive Surging or total loss of oil at bearings. I`ve seen loads of damaged thrust bearings, labyrinth seals and impellors - but never a snapped shaft. Was this the high speed or Drive Shaft?? What Chiller did this happen on??

[fahood93]

it is carrier centrfugal chiller , model 19XR-5050437DFS52S. The brocken shaft was high speed shaft. The sposnor explanation for failure cause was due to surge caused by power fluctuation .

[yorkman_gr]

that is correct surge can cause serious damages even can break the shaft and more

[james10]

If there was a fluctuation in the power supply the machine would trip, providing the control system is working 100% refrigerant shortage can cause surging which in turn can cause shaft and thrust bearing damage also irregular water flow can be the cause, before you carry out any repair to the unit be sure to check all other components in particular the anti-surge valve (hot gas) on the underside of the condenser it would be a shame to do all that work for it to fail again also check the impellor for damage and bear in mind if the impeller is damaged you will need to replace the diffuser aswell , I would not recommend trying to rebalance or repair the impeller in my experience when this has been done the thrust bearing go in no time.
good luck
James

[iceman2306]

i have seen 2 high speed shafts break and a couple bend, but only on the frame 5 compressors.
thats a frame 4 compressor, all caused by surging.
has it a fixed or variable diffuser.

[FRIDGE]

Hi,
Carrier 19XR chillers are protected against power fluctuations, hence machine would trip, does alarm history indicate power issues?

- has machine been stripped and rebuilt recently? ( service on time and compressor hours )( poor assembly)
- low load running results in poor oil return, increased high speed thrust bearing wear
- low load running (less than 50%) can cause high lift due due to guide vanes being almost closed; this would cause low end surging which would damage thrust bearings, increase the thrust, impeller touches the shroud and shaft twist, bends or snaps. ( poor chilled water flow? what does alarm history indicate? )
- high end surge also causes the above. ( poor condenser water flow? alarm history?)

if you stripped it down, what is the state of the impeller if any of it was recovered ;)