Seg XRI1-IR, Руководство пользователя

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16 TB XRI1-IR 02.00 E
6 Operations and settings
6.1 Setting procedure
After push button <SELECT/RESET> has been pressed,
always the next measuring value is indicated. Firstly
the operating measuring values are indicated and then
the setting parameters. By pressing the <ENTER> push
button the setting values can directly be called up and
changed.
6.1.1 Pickup current for phase
overcurrent element (I>)
The setting value for this parameter that appears on the
display is related to the nominal current (I
N
) of the re-
lay. This means: pickup current (Is) = displayed value x
nominal current (I
N
) e.g. displayed value = 1.25 then,
Is = 1.25 x IN.
6.1.2 Time current characteristics for
phase overcurrent element
(CHAR I>)
By setting this parameter, one of the following 4 mes-
sages appears on the display:
DEFT - Definite Time
NINV - Normal Inverse (type A)
VINV - Very Inverse (type B)
EINV - Extremely Inverse (type C)
Anyone of these four characteristics can be chosen by
using <+> <-> push buttons, and can be stored by us-
ing <ENTER> push button.
6.1.3 Trip delay or time multiplier for
phase overcurrent element (t
I>
)
Usually, after the characteristic is changed, the time
delay or the time multiplier should be changed accord-
ingly. In order to avoid an unsuitable arrangement of
relay modes due to carelessness of the operator, the
following precautions are taken:
After the characteristic setting, the setting process turns
to the time delay setting automatically. The LED tI> is
going to flash yellow to remind the operator to change
the time delay setting accordingly. After pressing the
<SELECT> push button, the present time delay setting
value is shown on the display. The new setting value
can then be changed by using <+> <-> push buttons.
If, through a new setting, another relay characteristic
other than the old one has been chosen (e.g. from
DEFT to NINV), but the time delay setting has not been
changed despite the warning from the flashing LED,
the relay will be set to the most sensitive time setting
value of the selected characteristics after five minutes
warning of flashing LED tI>. The most sensitive time set-
ting value means the fastest tripping for the selected re-
lay characteristic. When the time delay or the time
multiplier is set out of range (Text "EXIT" appears on the
display), the low set element of the overcurrent relay is
blocked. The "WARN"-relay will not be blocked.
For the XRI1-IR -version with directional feature, the dif-
ferent trip time delays or the time multipliers can be
chosen for forward and backward faults.
By setting the trip delay, the actual set value for for-
ward faults appears on the display first and the LED
under the arrows is alight green. It can be changed
with push button <+> <-> and then stored with push
button <ENTER>. After that, the actual trip delay (or
time multiplier) for backward faults appears on the dis-
play by pressing push button <SELECT> and the LED
under the arrows is alight red.
Usually this set value should be set longer than the one
for forward faults, so that the relay obtains its selectivity
during forward faults. If the time delays are set equally
for both forward and backward faults, the relay trips in
both cases with the same time delay, namely without
directional feature.
Note:
When selecting dependent tripping characteristics at
relays with directional phase current detection, atten-
tion must be paid that a clear directional detection will
be assured only after expiry of 40 ms.