Siemens siprotec 7SA6 User Manual page 285

Definite Time Very
High Set Current
Stage 3I >>>
0
"D333
"
I
E
3I >>>
0
1305 >EF BLK 3I0>>>
"D333D…ˆ†u7yx
" $
Yes
inrush-
No
stabilization
PƒÀ‚qrÃ"D333
" 
Inactive
Forward
Reverse
„1"
Non-Direct.
forwards
direction-
reverse
determination
Figure 6-61 Logic diagram of the 3I
Definite Time High
Set Current
Stage 3I >>
0
7SA6 Manual
C53000-G1176-C133-1
current transformers connected in a star arrangement must be available and
connected.
The earth current I = 3I
E
the set value ,!!!. If this value is exceeded and alarm is issued. After the
corresponding delay times 7 ,!!! have expired, a trip command is issued which
is also alarmed. The reset threshold is approximately 5 % + 0,5 mA below the pick-up
threshold.
The possibilities of selection are referred to in the heading "General". Figure 6-61
shows the logic diagram of the 3I
determination", "permissive teleprotection", "switch onto fault", and "inrush
stabilization" are common to all stages and described below. They may however affect
each stage individually. This is done with the following parameters:
• 2S PRGH ,!!!, determines the operating direction of the stage: )RUZDUG,
5HYHUVH or 1RQ'LUHFWLRQDO,
• ,!!! 7HOHS%,, determines whether a non-delayed trip with the teleprotection
scheme is possible (<HV) or not possible (1R),
• ,!!!627)7ULS, determines whether during energization of the feeder onto a
fault tripping with this stage shall be non-delayed (<HV) or not (1R) and
• ,!!!,QUXVK%ON, which is used to switch the inrush stabilization (rush blocking)
on (<HV) or off (1R).
&
&
" "
permissive
teleprot..
&
&
≥1
&
switch onto
fault
>>>–stage
0
The logic of the high set current stage 3I
3I0>>> is therefore to be replaced by ,!!, then, Figure 6-61 also applies for 3I
is passed through a numerical filter and then compared with
0
>>>–stage. The function modules "direction
0
" !
T
"D333ÃUryrƒ7D
Yes
≥1
No
FNo1310
>EF Inst TRIP
" &! TPUAÃPƒÃH‚qr
" #
PICKUP+DIRECT.
PICKUP
&
" &" UTPUAÃUv€rÃ9@G6`
>> is the same as that of the 3I
0
1354 EF 3I0>>>Pickup
UÃ"D333
0
≥1
EF 3I0>>> TRIP
1366
&
"D333TPUAU…vƒ
Yes
T 0
No
Functions
>>>–stage.
0
>>.
0
6-103