Dead Zone Configuration; Non-Directional Phase Overcurrent Protection - GE P741 Technical Manual

Settings
MiCOM P741, P742, P743
1.2.4 Dead Zone configuration ("Dead Zone Prot" menu – P742/P743)
Menu Text
Dead Zone Prot
I>DZ Current Set
Setting for the tripping characteristic for the minimum pickup phase dead zone element
I>DZ Time Delay
Setting for the minimum pickup phase dead zone element timer
Dead Earth Fault
Activates or deactivates the neutral dead zone protection. When activated, the following
menus are displayed.
IN>DZ Cur Set
Setting for the tripping characteristic for the minimum pickup neutral dead zone element
IN>DZ Time Delay
Setting for the minimum pickup neutral dead zone element timer
Note:
1.2.5 Non-directional Phase overcurrent protection ("Overcurrent" menu – P742/P743)
The overcurrent protection included in the P742 or P743 relay provides two stages non-
directional three-phase overcurrent protection with independent time delay characteristics.
All overcurrent settings apply to all three phases but are independent for each of the four
stages.
The first stage of overcurrent protection has time-delayed characteristics which are
selectable between inverse definite minimum time (IDMT), or definite time (DT). The second
stage has definite time characteristics only.
Menu Text
Overcurrent
I>1 Function
Setting for the tripping characteristic for the first stage overcurrent element.
Setting choice: Disabled, definite time (DT), IEC S(tandar) Inverse, IEC V(ery) Inverse,
IEC E(xtremely) Inverse, UK L(ong) T(ime) Inverse, EUUU Moderately) inverse, IEEE
V(ery) Inverse, IEEE E(xtremely) Inverse, US Inverse or US S(hort) T(ime) Inverse.
The next menus are displayed according to the function choice (refer to P74x/EN GS
section). When Disabled, the next menu is 'I>2 Function'.
I>1 Current Set
Pick-up setting for first stage overcurrent element.
I>1 Time Delay
Setting for the time-delay for the definite time setting if selected for first stage element.
I>1 TMS
Setting for the time multiplier setting to adjust the operating time of the IEC IDMT
characteristic.
Default Setting
1.20*I 0.05*I
n
1.00 s 0.00 s
Disabled Enabled / Disabled
1.20*I 0.05*I
n
1.00 s 0.00 s
is the CT nominal current.
I
n
Default Setting
Disabled Disabled, DT, IEC S Inverse, IEC V Inverse,
IEC E Inverse, UK LT Inverse, IEEE M
Inverse, IEEE V Inverse, IEEE E Inverse, US
Inverse, US ST Inverse
3.00*I 0.10* I
n
1.00s 0.00s
1.000 0.025
P74x/EN ST/Na7
Setting Range
Min. Max.
4.00*I
n n
100.00 s 0.01 s
4.00*I 0.01*I
n n
100.00 s 0.01 s
Setting Range
Min. Max.
32.00* I
n n
100.00s
1.200
(ST) 4-19
Step Size
0.01*I
n
n ST
Step Size
0.01* I
n
0.01s
0.025