Thytronic XMR-D - Page 197

FUNCTION CHARACTERISTICS
197
Cold load pickup
The second element may be blocked by means of the Cold Load Pickup (CLP)
[1]
function.
If the CLP function is enabled the element is blocked for an adjustable time interval, starting from the
starting control criterion (circuit breaker closure or I
RUN
threshold).
The CLP Activation time parameter (tLRCLP>>) may be adjusted inside the Set \ Profile A (or B) \
Locked rotor - 50S/ 51LR/14\ ILR>> Element \ Setpoints menu.
Starting control
If the CLPSourceparameter is set to IRUN and the maximum value of phase currents is lower than
0.1 I
B
, the protection is blocked off.
If the
CLPSourceparameter is set to CB and the circuit breaker is open, the protection is blocked
off.
The
CLP Source parameter, common for profiles A and B, is available inside the Set \ Starting
control set menu.
Note 1 The inverse time threshold, unlike the definite time, is not in any way conditioned by the CLP activation time
Setting example: I
MOT-ST
= 5I
LR>inv
With input current I = I
MOT-ST
and setting t
LR>inv
=10 s the operate time is t = 10 s
Operating characteristic concerning the locked rotor element (50S/51LR(48)/14)
F_48-Char.ai
t = t
LR
>
inv
· (I
MOT-ST
/I)
2
I
MOT-ST
I/
I
LR>inv
t [s]
1 2 3 4 5 6 7 8 9 10 20 50
0.01
0.1
1
10
100
250
1000
10 000
t
LR>inv
= 1 s
t
LR>inv
= 10 s
t
LR>inv
= 200 s
t
LR>inv
= 100 s
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021