48
48
NV10P - Manual - 01 - 2015
CHARACTERISTICS
Application notes concerning to the Vts positioning
• Both transducers residual as well as voltage and frequency VTs are normally to be installed up-
stream of the CB.
VOLTAGE AND FREQUENCY VTs POSITIONING
Only for static generators, it is permissible to install it downstream of the CB but:
exclusion of protective elements must be provided when CB is open (to avoid that the CB closing
is forbidden) and
when the CB closes (after removal of the exclusion), the SPI should automatically set the operate
time of the f>>, f<<, UE>> thresholds to a reduced time (while maintaining the response time of the
remaining thresholds) for a time of at least 30 s after the closing of the CB.
The element disabling when the circuit breaker is open can be selected by setting ON the
xxdisbyCB_OPEN
parameters inside the
Set \ Profi le A(or B) \ yy \ Setpoints
, menu where
xx
is is the element that you want to disable (eg: f>) and
yy
is the corresponding function (eg:
Over-
frequency-81O
).
When the CB closes, the operate time of the f >>, << f, UE >> elements is automatically adjusted to
a reduced value
tcxx>>def
for an adjustable time
tatcxx>>def
. The reduction of the operate
time for the second threshold can be selected by setting the
EnTcxx>>def
parameter inside the
Set \Profi le A(or B) \ yy \ xx>> Element \ Setpoints
menu, while the timers are adjustable inside the
Set \Profi le A(or B) \ yy \ xx>> Element \ Defi nite time
menu.
—
A)
B)
A)
B)
Grid
Load
2xVT-I
phase-phase
3xVT-I
phase-ground
3xVT-NI
phase-ground
CB
Grid
Load
CB
I
SPI
SPI
Grid
Load
2xVT-I
phase-phase
3xVT-I
phase-ground
3xVT-NI
phase-ground
CB
Grid
Load
CB
I
SPI
SPI
Grid
Load
3xVT-NI
phase-ground
SPI
SPI
DDI
Grid
Load
DDI
I
2xTV-I
phase-phase
Grid
Load
3xVT-NI
phase-ground
SPI
SPI
DDI
Grid
Load
DDI
I
2xTV-I
phase-phase
Operate time reduction after CB closing (eg: f>> element)
RESET
t
f>>
0
T
( closing)
DDI OFF->ON
( 1
≡
upstream)
EnTcf>>def
t
atcf>>def
0
T
RESET
t
f>>def
t
cf>>def
t
atcf>>def
“1”
“0”
TV downstream
CB State
CB CLOSED (52a=ON)
CB OPEN (52a=OFF)
t
f>>
=
t
cf>>def
t
f>>
=
t
cf>>def
t
atcf>>def
t
f>>
t
f>>
=
t
f>>def
Operate time reduction after CB closing (eg: f>> element)
RESET
t
f>>
0
T
( closing)
DDI OFF->ON
( 1
≡
upstream)
EnTcf>>def
t
atcf>>def
0
T
RESET
t
f>>def
t
cf>>def
t
atcf>>def
“1”
“0”
TV downstream
CB State
CB CLOSED (52a=ON)
CB OPEN (52a=OFF)
t
f>>
=
t
cf>>def
t
f>>
=
t
cf>>def
t
atcf>>def
t
f>>
t
f>>
=
t
f>>def