Janitza AHF
37
5.5.3 CT installation on the grid side (closed loop)
If it is not possible to install the CT group on the load side, or if current transformers are
already present on the grid side, the CT groups can also be connected on the grid side (see
Kirchhoff’s law of current distribution).
• When there is an existing compensation on the grid side, there are two options for the
installation of the current transformer group: Figure 3-23 (a) and 3-23 (b).
• When there is an existing compensation on the load side, the installation
of the CT groups must done as shown in Figure 3-24.
AHF
1S
1
1S
2
CT
Kompensation
CT
1S
1
1S
2
CT
CT
1S
1
1S
2
AHF
1S
1
1S
2
CT
CT
2S1
2S2
AHF
AHF
AHF
1S
1
1S
2
2S
2
2S
1
P
1
P
2
P
1
P
2
1S
1
1S
1
1S
2
1S
2
2S
2
2S
1
Figure 3-23 (a)
Current transformer on the grid side
with existing compensation on the grid
side
AHF
1S
1
1S
2
CT
Kompensation
CT
1S
1
1S
2
CT
CT
1S
1
1S
2
AHF
1S
1
1S
2
CT
CT
2S1
2S2
AHF
AHF
AHF
1S
1
1S
2
2S
2
2S
1
P
1
P
2
P
1
P
2
1S
1
1S
1
1S
2
1S
2
2S
2
2S
1
Figure 3-22
Current transformer on the grid side
Grid side
Grid side
Load side
Load side
NOTE
When there is more than one filter module, current transformers must be installed in the
supply line to the AHF: this is the only way for the load current to be captured. This is not
necessary only if there is only one filter module.
