Differential Protection Configuration; Differential Phase Fault Configuration - GE P741 Technical Manual

P74x/EN ST/Na7
(ST) 4-14
−
There are four groups of protection settings, with each group containing the same setting
cells. One group of protection settings is selected as the active group, and is used by the
protection elements. The settings for group 1 are shown. The settings are discussed in the
same order in which they are displayed in the menu.
1.2.1 Differential Protection Configuration ("Diff Busbar Prot" menu – P741)
Differential Elements 87BB
ST
The differential element has independent settings for phase and earth (sensitive) faults,
which are used for all zones and the check zone independently.
1.2.1.1

Differential phase fault Configuration

DIFF BUSBAR PROT
Diff Phase Fault (Diff busbar protection menu first part)
CZ Parameters
Phase slope kCZ
Slope angle setting for the check zone biased differential element.
I CZ>2 Current
D
Setting that determines the minimum differential operating current for the check zone
biased differential element
Zone Parameters
Phase slope k2
Slope angle setting for all discriminating zone biased differential elements
I >2 Current
D
Setting that determines the minimum differential operating current for all the discriminating
zone biased differential elements
Common
>1 Current
I
D
Setting for the phase circuitry fault monitoring characteristic for the minimum pickup
Phase slope k1
Slope angle setting for the phase circuitry fault monitoring characteristic.
>1 Alarm Timer
I
D
Setting for the operating time delay of the phase circuitry fault monitoring
• Dead Zone configuration ("Dead Zone Prot" menu),
• Non-directional Phase overcurrrent protection ("Overcurrent" menu),
• Non-Directional Earth Fault Overcurrent Protection and External Fault Detection by
High-Set Overcurrent ("Earth Fault" menu),
• Circuit breaker fail and undercurrent function ("CB Fail" column),
• Supervision CTS ("Supervision" menu).
Programmable scheme logic (PSL) that also includes InterMiCOM signals mapping.
Menu Text Default Setting
30%
1200 A
60%
1000 A
100 A
10%
5.0s
MiCOM P741, P742, P743
Setting Range
Min. Max.
0% 90%
50 A 30.000 A
20% 90%
50 A 30.000 A
10 A 500 A
0% 50%
0.0s 600.0s
Settings
Step Size
1%
10 A
1%
10 A
10 A
1%
0.1s