Toshiba GR200 Series Instruction Manual page 153

Enhances in Z1G, Z1XG & Z5G zones
The Z1G, Z1XG, and Z5G zones are normally applied for instantaneous tripping; they can have
their own, dedicated 'Covering zones'. The user can program the reactance reaches using
settings [Z1G-CovCoeff], [Z1XG-CovCoeff] and [Z5G-CovCoeff] in the associated operating
zone reach.
The user is recommended so that the reach of 'Covering zones' is set to at least 1.5 times
the reach of the associated operating zones. This 'Covering zones' does not have zero-sequence
compensation; hence, the user can select maximum, compensated reach of the operating zone
as the base value.
The resistance reaches of the 'Covering zones' are automatically set to be identical to the
operating zone resistance reaches; hence the user does not need to consider them.
Figure 2.10-36 illustrates the Z1G covering zone (Z1GCOV) characterized with setting
[Z1G-CovCoeff]; it shows the Z1GCOV element can operate between the zone2 and the zone3.
X
Z3G-X.Reach
Z2G-X.Reach
Z1G-X.Reach
Z1G element
Figure 2.10-36 Quad covering zone in Z1G programmed with Z1G-CovCoeff
Enhances in Z2G, Z3G & Z4G zones
A common covering zone is provided in Z2G, Z3G, and Z4G zones. This common zone is
automatically set to be the same as the largest of three zones; hence, the user need not have
settings.
300%
150%
100%
R
- 130 -
6F2S1914 (0.49)
X
Expansion made with setting [Z1G-CovCoeff]
Directional element (DR)
Z1GCOV element
GRL200 (Soft 033 & 037)
Resistive element (R)
R