ISA T1000 PLUS User Manual page 94

DOC. MIE91093 Rev. 1.34 Page 94 of 145
V
R N
V

I
R
R
V V
T S
This instance applies to phase 1 fault: as test starts, the value
of V1 goes from VN to Vf; at the meantime, If is applied, at
the pre-set phase angle.
1) Fault current
The current will be adjusted only on the faulty phase (1, 2
or 3), while the others remain at zero; its value is the one
selected by the operator (for instance, 10 A).
2) Healthy voltages phase angles
Choose the test angle in the R-X plane. If the distance relay is
set on the CT star point towards Busbar, the angle Φ(I-V) has
the same value but negative, otherwise it has the same value.
These angles depend upon the test angle and the supply: see
the table below. The angle is adjusted prior to actual zone
testing, as follows.
Start the test; adjust the fault current; adjust the fault voltage
at 30 V. Now select the auxiliary Vac phase with respect to the
current, as follows:
AUX VAC/DC > Aux Vac control > Phase > Reference:
current ESC
This adjustment will not be modified during tests.