ABB PQFS Installation, Operation And Maintenance Instructions page 120

8.6.2.3.3
If the main bus bar is available and all security rules are taken, it is possible to use the
two-channel scopemeter in order to see if the current measured through the CT is
matching the real current in the bus. Connecting the current probes as shown on
84. The two traces must be in phase and of the same shape (the magnitude could be
different as the gains are different) if the wiring is correct.
Figure 84: Connection of the scopemeter for checking the CT in phase L1 by comparing the
This operation has to be repeated for the remaining two phases for a complete check.
The current probes have to be changed accordingly.
120 Commissioning instructions ç Manual Power Quality Filter PQFS
L1 K
L2
Supply side
L3
k
N
Figure 83: Connection of the scopemeter for checking CT in phase L3
Checking the correct connection of the CTs with two current probes
L1 K
L2
Supply side
L3
k
N
L
K L
K L
l
k l
k l
X21.1
Positive direction
X21.2
X21.3
X21.4
X21.5
X21.6
Ch1
Positive direction
L
K L
K
l
k l
k
Positive direction
currents
Load side
N L1 L2 L3
PQF
Ch2
L
l
N L1 L2 L3
X21.1
X21.2
X21.3
PQF
X21.4
X21.5
X21.6
Ch1 Ch2
Figure
Load side