Carrier PIC 5+, Installation, Operation And Maintenance Instructions

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6.7 Surge prevention trouble shooting guide:
1. If chiller surges very frequently, the surge prevention line should be decreased
a. If chiller surges only at full load region, Delta Tsmax should be decreased by 0.28°C for each step until
there is no abnormal surge occurs. See Fig. 48 for the effect of delta Tsmax on surge prevention line.
b. If chiller surges only at low load region, Delta Tsmin should be decreased by 0.28°C for each step until
there is no abnormal surge occurs. See Fig. 49 for the effect of delta Tsmin on surge prevention line.
c. If chiller surges only at medium load region, surge line shape factor should be increased by 0.01 for
each step until there is no abnormal surge occurs. See Fig. 50 for the effect of surge line shape factor on
surge prevention line.
d. If chiller surges at all the regions, delta Tsmax, delta Tsmin and surge line shape factor can be
adjusted at the same time.
2. If chiller no surge but efficiency cannot meet the target, the surge prevention line should be increased
a. If the problem only occurs at full load region, Delta Tsmax should be increased by 0.28°C for each step
until chiller enters real surge. See Fig. 48 for the effect of delta Tsmax on surge prevention line.
b. If the problem only occurs at low load region, Delta Tsmin should be increased by 0.28°C for each step
until chiller enters real surge. See Fig. 49 for the effect of delta Tsmin on surge
prevention line.
c. If the problem only occurs at medium load region, surge line shape factor should be decreased by 0.01
for each step until chiller enters real surge. See Fig. 50 for the effect of surge line shape factor on surge
prevention line.
d. It the problem occur at all the regions, delta Tsmax, delta Tsmin and surge line shape factor can be
adjusted at the same time.
The effect of surge line speed factor on surge prevention line is shown in Fig. 51.
Fig 48
– Effect of surge delta TSmax on Surge prevention