Woodward
Manual MRIK3-C EN
12
DOK-TD-MRIK3-C Rev. A
Figure 4.3: Measuring of phase currents and earth current detection in Holmgreen connection (IE)
This kind of connection can be used where three phase CTs are available and a combination of
phase and earth current measuring is required.
Figure 4.4: Measuring of earth current with core-type CT (IE)
With the combination of phase and earth current measuring, CTs to be connected according to
Figure 4.3 or Figure 4.4.
P1
P2
S1
S2
P1
P2
S1
S2
P1
P2
S1
S2
I1
I2
I3
IE
L1.1
B3
B4
L1.2
L2.1
B5
L2.2
B6
L3.1
B7
L3.2
B8
B1
B2
L1
L2
L3