10
CU R R E NT A N D VOLTAG E I N STRU M E NT TR A N S FOR M E R S
I N S T R U C T I O N S FO R I N S TA L L AT I O N , USE A N D M A I N T EN A N C E
- Voltage transformers according to IEC
a
n
N
PE
a1
a2
n
N
PE
a
n
da
dn
N
PE
1a
1n
2a
2n
N
PE
1a1 1a2 2a1 2a2
1n
2n
N
PE
1a
2a
da
1n
2n
dn
N
PE
1a
2a
3a
1n
2n
3n
N
PE
1a1 1a2 2a2 da1 da2
1n
2a1
2n
dn
N
PE
a1
a2
da1 da2
n
dn
N
PE
a1
a2
da
n
dn
N
PE
a
b
PE
a1
a2
b
PE
1a
1b
2a
2b
PE
a
b
da
dn
PE
1a1 1a2 2a1 2a2
1b
2b
PE
1 measuring winding with 1 tap
2 measuring
1 mea residual
2 measuring winding with tap
1 measuring winding with no tap
1 measuring winding with 1 tap
1 mea residual
2 measuring winding with no tap
2 measuring winding with 1 tap
2 mea residual
3 measuring
2 measuring with tap + residual
with 1 tap
1 measuring with tap + residual
with 1 tap
1 measuring with tap + residual
1 measuring
Variants of connections of double row terminal - One pole VT
according to IEC
Variants of connections of double row terminal - Double pole VT
according to IEC
Residual voltage windings connected to open delta must have dn terminal earthed
only on one of three transformers (earthing screws at dn terminals of others two
transformers have to be removed).
