176
FUNCTION CHARACTERISTICS
The second overcurrent element can be programmed with definite or inverse time characteri-
stic by setting the I> Time characteristic (
I(H)>>Curve
) parameter (
DEFINITE, I2t
) available
inside the
Set \ Profile A (or B) \ Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Setpoints
menu.
The trip of
I(H)
> element may be inhibited by the start of the second and/or third element (
I(H)
>>,
I(H)
>>>) by setting
ON
the Disable I(H)> by start I(H)>>, Disable I(H)>> by start I(H)>>> (
I(H)>di-
sbyI(H)>>, I(H)>disbyI(H)>>>
) parameters available inside the
Set \ Profile A (or B) \ Phase
overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Setpoints
menus.
Similarly the trip of the
I(H)
>> element may be inhibited by start of the third element (
I(H)
>>>) by
setting
ON
the Disable I(H)>> by start I(H)>>> (
I(H)>>disbyI(H)>>>
) parameter available
inside the
Set \ Profile A (or B) \ Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Setpoints
menu.
All the named parameters can be set separately for
Profile A
and
Profile B
(
Set \ Profile A (or B) \
Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Setpoints
menus).
An adjustable reset time delay is provided for every threshold (
t
(H)
>
RES
,
t
(H)
>>
RES
,
t
(H)
>>>
RES
).
Breaker failure (BF)
Each thresholds (I>, I>>, I>>>) can be associated to BF (H) and BF (L) protection by activating the
relative parameter in the matrices “Selection of function tripping for BF (H)” or “Selection of function
tripping for BF (L)” in relevant
BF
menus
[1]
:
• Set \ Profile A (or B) \ Breaker failure - BF side H
• Set \ Profile A (or B) \ Breaker failure - BF side L
Second harmonic restraint
For all overcurrent elements, a block from the second harmonic restraint may be set by setting
ON
the
I>2ndh-REST, I>>2ndh-REST, I>>>2ndh-REST
parameters inside the
Set \ Profile A
(or B) \ Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Setpoints
menus.
Cold load pickup
If the CLP function (Cold Load Pick-up) is enabled for element blocking, the selected threshold may
be blocked for an adjustable time interval, starting from the circuit breaker closure.
This operating mode may be select by setting
ON-Element blocking
the
I(H)CLP> Mode, I(H)
CLP>> Mode
and/or
I(H)CLP>>> Mode
parameters.
If the CLP function (Cold Load Pick-up) is enabled for threshold change, the selected threshold may
be changed for an adjustable time interval, starting from the circuit breaker closure.
This operating mode may be select by setting
ON-Change setting
the
I(H)CLP> Mode, I(H)
CLP>> Mode
and/or
I(H)CLP>>> Mode
parameters, whereas the operating thresholds wi-
thin the CLP may be adjusted inside the
Set \ Profile A (or B) \ Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Definite time (Inverse time)
menus.
For both operating modes the CLP Activation time parameters (
tCLP>, tCLP>>, tCLP>>>
) may
be adjusted inside the
Set \ Profile A (or B) \ Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>>
Element
,
I(H)>>> Element) \ Setpoints
menus.
For every of the three thresholds the following block criteria are available:
Logical block (Block1)
If the
I(H)>BLK1, I(H)>>BLK1
and/or
I(H)>>>BLK1
enabling parameters are set to
ON
and
a binary input is designed for logical block (Block1), the concerning element is blocked off whenever
the given input is active.
[2]
The enabling parameters are available inside the
Set \ Profile A (or B) \
Phase overcurrent-50/51 side H \
I(H)> Element
(
I(H)>> Element
,
I(H)>>> Element) \ Setpoints
menus,
while the
Block1
function must be assigned to the selected binary input inside the
Set \ Board1(2)
inputs \ Binary input IN1-1...INx-x
menus.
Note 1 The common settings concerning the Breaker failure protection are adjustable inside the
Breaker Failure - BF
menu.
Note 2 The exhaustive treatment of the logical block (Block 1) function may be found in the “Logic Block” paragraph inside
CONTROL AND MONITOR-
ING
section
I> element phase overcurrent timers - 50/51 side H
Timers-F50-51.ai
I(H)> Start
I(H)> Trip
RESET
INPUT
t
(H)
>
RES
t
(H)
>
RES
t
(H)
>
RES
t
(H)
>
t
(H)
>
t
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021