- 18 -
EFFECT OF POLARITY REVERSAL
The compressor is still loaded with 100 kW on each phase. The load power factor (PF) is 1. PF in phase
L2 will show -1.00 due to reverse polarity. The result is that total compressor power displayed by the
controller is 100 kW.
Measured values are as follows:
kW
kVAr
kVA
pf
Phase L1
100.0
0.0
100
1.00
Phase L2
-100.0
0.0
100
-1.00
Phase L3
100.0
0.0
100
1.00
Total
100.0
0.0
300
0.33
EFFECT OF PHASE SWAPPING
The compressor is still loaded with 100 kW in each phase. The load power factor (PF) is 1. PF in phases
L2 and L3 will show -0.50 due to phase shift between voltages and currents which is caused by CT
swapping. The result is that total compressor power displayed by the controller will be 0 kW.
Measured values are as follows:
kW
kVAr
kVA
pf
Phase L1
100.0
0.0
100
1.00
Phase L2
-50.0
86.6
100
-0.50
Phase L3
-50.0
-86.6
100
-0.50
Total
0.0
0.0
300
0.0
