ISA T1000 PLUS User Manual page 100

DOC. MIE91093
FAULT V1
ANGLE
V2
V3
PRE-FAULT V1
ANGLE
V2
V3
In our instance, φX1 is 19°; if φ = 75°, phase angles to be
programmed are the followings.
FAULT
FAULT V1
ANGLE
V2
V3
PRE-FAULT V1
ANGLE
V2
V3
These values apply for the test of the zone having the
impedance of 1 Ohm ; for other zones they should be
repeated.
This made clear, the other thing to make clear is how to
perform the test. Once all values are correctly programmed
and adjusted, start the test: the relay will trip in zone N or in
zone N+1. To check the setting, in the first case you need to
increase Vf until the relay trips in zone N+1; in the second
case you should decrease Vf until the relay trips in zone N.
Once this is obtained, the zone setting is computed based
upon the average of two Vf voltages that make the relay to
trip in the different zones, Vf1 and Vf2:
Z = (Vf1 + Vf2) / (4 * If)
Rev. 1.34
30°-φ
-30° -φ
0°
- (60° -
φX1)
60° - φX1 - (60° - φX1)
0°
1-2
-45°
-105°
0°
- 41°
41°
0°
Page 100 of 145
0° -30° -
30°-φ
-30° -φ 30°-φ
0°
60° - φX1 - (60°
2-3
0°
-45°
-105°
0°
- 41°
41°
φ
0°
60° -
φX1
0°
-
φX1)
3-1
-105°
0°
-45°
41°
0°
- 41°