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centrifugal chiller high current starting!
- Thread starter naifmbo
- Start date
Yorkman
Mechanical
- May 10, 2006
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You did not mention the type of starter, high current at start up is a relative term, Is this an accross the line starter, Part-wind, an auto transformer, a solid state starter or V.S.D.? Depending on the starter, you might see currents at locked rotor amps (L.R.A.) this would be momentarily at 4-5 times F.L.A. Some solid state starters keep current at 45% L.R.A. The V.S.D. keeps starting currents at or below F.L.A.
Is the starter tripping on overcurrent? Make sure you have good in coming power to all three phases.
If the starter is not calibrated correctly this could cause a false high current reading, if this is an older machine with a new problem then I would not think this is the issue.
Here are some other things to check, verify that the inlet vanes are closed at startup, there is usually an end switch to verify that, if this is malfuctioning you might be trying to start this machine with the inlet vanes at the wrong position. I would start there. If that checks out ok, you want to check the condition of the motor starter and it's connections. Check the motor windings by using a megger to ground check, and if possible a winding to winding check if the phases can be isolated.
If all that appears ok you could be looking at an internal mechanical problem (bearings, gears, or thrust bearing failure. On an open drive machine this can be checked by trying to turn the compressor shaft by hand/strap wrench (high pressure machines can be tough), depending on the size of the machine you may want to remove the coupling to do this. If you can not turn the shaft an inspection would be in order. On a semi-hermetic machine you will have to open the machine for in spection. Hope things turn out ok. A.J. Gest York International
Is the starter tripping on overcurrent? Make sure you have good in coming power to all three phases.
If the starter is not calibrated correctly this could cause a false high current reading, if this is an older machine with a new problem then I would not think this is the issue.
Here are some other things to check, verify that the inlet vanes are closed at startup, there is usually an end switch to verify that, if this is malfuctioning you might be trying to start this machine with the inlet vanes at the wrong position. I would start there. If that checks out ok, you want to check the condition of the motor starter and it's connections. Check the motor windings by using a megger to ground check, and if possible a winding to winding check if the phases can be isolated.
If all that appears ok you could be looking at an internal mechanical problem (bearings, gears, or thrust bearing failure. On an open drive machine this can be checked by trying to turn the compressor shaft by hand/strap wrench (high pressure machines can be tough), depending on the size of the machine you may want to remove the coupling to do this. If you can not turn the shaft an inspection would be in order. On a semi-hermetic machine you will have to open the machine for in spection. Hope things turn out ok. A.J. Gest York International
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