Basler Electric DGC-2020HD - Manual (Page 351)

9469300990 Rev B 341
Table 95. Characteristic Curve Cross-Reference
Curve Curve Name Similar To
S1 Short Inverse ABB CO-2
S2 Short Inverse GE IAC-55
L1 Long Inverse ABB CO-5
L2 Long Inverse GE IAC-66
D Definite Time ABB CO-6
M Moderately Inverse ABB CO-7
I1 Inverse Time ABB CO-8
I2 Inverse Time GE IAC-51
V1 Very Inverse ABB CO-9
V2 Very Inverse GE IAC-53
E1 Extremely Inverse ABB CO-11
E2 Extremely Inverse GE IAC-77
A Standard Inverse Refer to BS 142
B Very Inverse (I
2
t) Refer to BS 142
C Extremely Inverse (I
2
t) Refer to BS 142
G Long Time Inverse (I 2 t) Refer to BS 142
F Fixed Time n/a
46 K Factor n/a
P User Programmable n/a
Time Dial Setting Cross-Reference
While the time characteristic curve shapes have been optimized for each relay, time dial settings of Basler
Electric relays are not identical to the settings of electromechanical induction disk overcurrent relays.
Table 96 helps you convert the time dial settings of induction disk relays to the equivalent setting for
Basler Electric relays. Enter time dial settings using BESTCOMSPlus. For more information, refer to the
Generator Protection chapter.
Using Table 96
Cross-reference table values were obtained by inspection of published electromechanical time current
characteristic curves. The time delay for a current of five times tap was entered into the time dial
calculator function for each time dial setting. The equivalent Basler Electric time dial setting was then
entered into the cross-reference table.
If your electromechanical relay time dial setting is between the values provided in the table, it will be
necessary to estimate the correct intermediate value between the electromechanical setting and the
Basler Electric setting.
The DGC-2020 has a maximum time dial setting of 9.9. When the F (fixed) curve is selected, the
maximum timing range is 7,200 seconds. The Basler Electric equivalent time dial setting for the
electromechanical maximum setting is provided in the cross-reference table even if it exceeds 9.9. This
allows interpolation as noted above.
Basler Electric time current characteristics are determined by a linear mathematical equation. The
induction disk of an electromechanical relay has a certain degree of non linearity due to inertial and
friction effects. For this reason, even though every effort has been made to provide characteristic curves
with minimum deviation from the published electromechanical curves, slight deviations can exist between
them.
DGC-2020HD Time Curve Characteristics