Thytronic NA20, Manual, Page: 59 / 208

FUNCTION CHARACTERISTICS
59 NA20 - Manual - 04 - 2022
If the CLP function (Cold Load Pick-up) is enabled for blocking 49, the thermal image is blocked for an
adjustable time interval, starting from the circuit breaker closure.
[1]
The operating mode parameter
may be select by setting ON-Element blocking the DThCLP Mode parameter inside the
Set \
Profile A(or B) \ Thermal image-49 \ Common configuration
menu.
If the CLP function (Cold Load Pick-up) is enabled for threshold change, the equivalent thermal cur-
rent may be decreased by means a K
INR
factor for an adjustable time interval, starting from the
circuit breaker closure.
[2]
The operating mode parameter may be select by setting ON-Change
setting the DThCLP Mode parameter inside the
Set \ Profile A(or B) \ Thermal image-49 \
Common configuration
menu.
For the Dth> threshold, a block from the second harmonic restraint may be set by setting
ON the DTh>2ndh-REST parameter inside the
Set \ Profile A(or B) \ Thermal image-49 \
Common configuration
menu.
All elements can be enabled or disabled by setting ON or OFF the DThetaAL1 Enable , DTheta-
AL2 Enable and/or DTheta> Enable parameters inside the
Set \ Profile A(or B) \ Thermal image-
49 \ DthAL1 Element
(
DthAL2 Element
,
Dth> Element)
menus.
The trip element (Dth>) may be inhibited when a start of at least one of the overcurrent element
(50/51) is active, if the Dth>disby50-51 parameter is set ON inside the
Set \ Profile A(or B) \Ther-
mal image-49 \ Dth> Element
menu.
The D q
IN
parameter sets a minimum level of previous thermal image D q
p
when the protection relay
is powered or when a remote (binary input) or local (keyboard or ThyVisor) command is issued.
The DthIN parameter may be adjusted inside the
Set \ Profile A(or B) \ Thermal image-49\
Common configuration
menu.
To active the D q
IN
preset value remotely, a binary input must be programmed as Init DTheta func-
tion inside the
Set \ Inputs \ Binary input IN1, Binary input INx
menu.
The trip element can produce the Breaker Failure output if the Dth> BF parameters is set to ON. The
parameter is available inside the
Set \ Profile A(or B) \ Thermal image-49 \ Dth> Element
menu.
[3]
The IB setting is adjustable inside the
Set \ Profile A(or B) \ Base current IB
menu.
Note 1 The CLP function (Cold Load Pick-up) with blocking of the 49 element has priority compared with the second harmonic restraint function, so, if
the equivalent thermal current is enabled, the latter is not reduced when a second harmonic restraint is active.
Note 2 The CLP function (Cold Load Pick-up) with threshold change of the 49 element has priority compared with the second harmonic restraint func-
tion, so, if the equivalent thermal current is enabled, the latter is not reduced when a second harmonic restraint is active.
Note 3 The common settings concerning the Breaker failure protection are adjustable inside the Breaker Failure - BF menu.
all-F49.ai
K
INR
T DthIN DthCLP Mode Dth2ndh REST tDthCLP
Common configuration
I
th
Dth> Element
Trip DTh>
DTh> Enable DTh>
Trip DTh>
Dth>BF
&
Dth>BF
BLK2OUT
Dth>BLK2OUT
& Trip Dth>
Trip Dth>
BLK2INDth>
Block2
&
Dth>BLK2IN
&
DthAL1 Element
DThAL1
DThAL1
DThAL1 DThAL1 Enable
I
th
BLK2OUT
DthAL1BLK2OUT
&
Block1
BLK1DthAL1 &
DthAL1BLK1
&
Dth>AL1
DthAL1
BLK2INDthAL1
Block2
&
DthAL1BLK2IN
&
DthAL2
BLK2INDthAL2
Block2
&
DthAL2BLK2IN
&
DthAL2 Element
DThAL2
DThAL2 DThAL2 Enable
I
th
BLK2OUT
DthAL2BLK2OUT
&
Block1
BLK1DthAL2
&
DthAL2BLK1
&
Dth>AL2
Dth>AL2
Block1
BLK1Dth>
&
Dth>BLK1
Trip Dth> &
&
50-51 inhibition
Dth>disby50-51
General logic diagram of the thermal image elements - 49