Thytronic NA11, Manual

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50
50 NA11 - Manual - 02 - 2009 FUNCTION CHARACTERISTICS
The second overcurrent element can be programmed with defi nite or inverse time characteristic
by setting the I> Time characteristic (
I>>Curve
) parameter (
DEFINITE, I2t
) available inside the
Set \ Profi le A(or B) \ Phase overcurrent-50/51\ I>> Element \ Setpoints menu.
The trip of I > element may be inhibited by the start of the second and/or third element ( I >>, I >>>) by set-
ting
ON
the Disable I> by start I>>, Disable I>> by start I>>> (
I>disbyI>>, I>disbyI>>>
) parameters
available inside the Set \ Profi le A(or B) \ Phase overcurrent-50/51 \ I>> Element ( I>>> Element) \Setpoints
menus.
Similarly the trip of the
I >> element may be inhibited by start of the third element ( I >>>) by setting
ON
the Disable I>> by start I>>> (
I>>disbyI>>>
) parameter available inside the Set \ Profi le A(or
B) \ Phase overcurrent-50/51\I>>> Element \ Setpoints menu.
All the parameters can be set separately for Profi le A and Profi le B ( Set \Profi le A(or B)\Phase over-
current-50/51 \ I> Element ( I>> Element , I>>> Element) \Setpoints menus).
An adjustable reset time delay is provided for every threshold ( t
>RES
, t
>>RES
, t
>>>RES
).
Each overcurrent element can produce the Breaker Failure output if the
I> BF
,
I>> BF
and/or
I>>> BF
parameters are set to
ON.
The parameters are available inside the Set \ Profi le A(or B) \
Phase overcurrent-50/51 \ I> Element ( I>> Element , I>>> Element) \ Setpoints menus.
[1]
For all overcurrent elements, a block from the second harmonic restraint may be set by set-
ting
ON
the
I>2ndh-REST, I>>2ndh-REST, I>>>2ndh-REST
parameters inside the
Set \ Profi le A(or B) \ Phase overcurrent-50/51 \ I> Element ( I>> Element , I>>> Element) \ Setpoints
menus.
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
ICLP> Mode, ICLP>>
Mode
and/or
ICLP>>> 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
ICLP> Mode, ICLP>>
Mode
and/or
ICLP>>> Mode
parameters, whereas the operating thresholds within the CLP
may be adjusted inside the Set \ Profi le A(or B) \ Phase overcurrent-50/51 \ I> Element ,( I>> Element ,
I>>> Element) \ Defi nite time (Inverse time) menus.
For both operating modes the CLP Activation time parameters (
tCLP>, tCLP>>, tCLP>>>
) may
be adjusted inside the Set \ Profi le A(or B) \ Phase overcurrent-50/51 \ I> Element ( I>> Element ,
I>>> Element) \ Setpoints menus.
Note 1 The common settings concerning the Breaker failure protection are adjustable inside the Breaker Failure - BF menu.
Timers-F50-51.ai
I> Start
I> Trip
t
>
t
>
RESET
INPUT
t
>RES
t
>RES
t
>RES
t
I> element phase overcurrent timers - 50/51
Timers-F50-51.ai
I> Start
I> Trip
t
>
t
>
RESET
INPUT
t
>RES
t
>RES
t
>RES
t
I> element phase overcurrent timers - 50/51