VFD Compressor Minimum Speeds
Email from Clay Brown on 1/2/20
See the below table for minimum speed setting for the ZPV variable speed compressors. These minimums are expressed as a percentage of the design RPM used for the vbalance selection. These minimum speeds have been selected to maintain a minimum velocity in the suction lines for better oil return.
We need to make sure that we are setting the minimum speed for ALL ZPV compressors per the table below. The ZPV066 and ZPV096 have a different minimum at 3600 RPM because we are using a smaller suction line size on these models. We also need to make sure that these minimums are properly communicated to the ATC for controls by others projects.
MINIMUM SPEED (%) | ||||
DESIGN RPM |
ZPV063 |
ZPV066 |
ZPV096 | |
3600 |
68% |
50% |
50% | |
4200 |
58% |
58% |
58% | |
4800 |
50% |
50% |
50% | |
5400 |
45% |
45% |
45% | |
6000 |
40% |
40% |
40% | |
6600 |
38% |
38% |
38% | |
7200 |
35% |
35% |
35% | |
