ABB PQFS Installation, Operation And Maintenance Instructions page 50

The terminal block X21 can handle control cable wiring with sections from 2.5 mm² to 10
mm².
In addition to the 6-wire CT cabling approach shown in
approach may also be used. This approach is illustrated in
secondary terminal to which the guard circuit is connected is interconnected between the
CTs and also on the filter terminal X21. One common cable is used for this terminal. Note
that this cable must be able to withstand three times the secondary current rating of the
CTs.
50 Electrical design and installation ç Manual Power Quality Filter PQFS
The l (S2) terminal of the line 3 CT (L3, Blue, W) must be connected to
o
terminal X21-6 of the filter
· The CT connection terminal X21 is located in the middle of the top plate of the
filter (Cf. Figure 42).
L1 K
L2
Supply side
L3
k
N
To X21.1/X21.2
K = P1, L = P2, k = S1, l = S2
Figure 41: Basic CT connection example for a single unit active filter.
Figure 42: Location of the CT connection terminal X21 in the PQFS
L
K L
K
l
k l
k
To X21.5/X21.6
To X21.3/X21.4
Load side
L
l
N L1 L2 L3
X21.1
X21.2
X21.3
PQF
X21.4
X21.5
X21.6
Figure 41 above, a 4-wire
Figure 43. In this case the CT