ABB ZX0 - Earthing of E-N Windings

30 | Manual ZX0 HB 600 en - Revision 05
-F
-R
dn
da
-T15L3
dn
da
-T15L2
dn
da
-T15L1
Earthing of e-n windings
If the e-n windings of the voltage transformers are damped with
a resistor, the windings connected in an open delta are to be
earthed at one point. The circuit can be earthed
- in the low voltage compartment (figure 2.3.5.2.3) or
- on the terminal block of a voltage transformer (figure
2.3.5.2.4).
Perform measurements to ascertain which earthing method ap-
plies to your system.
-F
-R
dn
da
-T15L3
dn
da
-T15L2
dn
da
-T15L1
Fig. 2.3.5.2.3: Earthing of the circuit in the low voltage compartment
Do not earth here!
Without earthing screw on
terminal "dn"
Fig. 2.3.5.2.4: Earthing the circuit on the terminal board of a transformer
Earthing in the low voltage
compartment
Do not earth here!
Without earthing screw on
terminal "dn"
Earth here!
With earthing screw on
terminal "dn"