Heavy Current Blocking Element; Overcurrent Protection Settings - NR Electric PCS-9611 Instruction Manual

I
max
|Ia
2
|Ib
2
|Ic
2
|I
max2
[50/51P.Opt_Hm_Blk]
[50/51P1.En_Hm_Blk]
Figure 3.3-9 Logic diagram of the OC1 phase A harmonic blocking element
Where:
[50/51P1.En_HarmBlk] is the logic setting of the harmonic blocking element of the stage 1
overcurrent protection;
[50/51P.K_Hm2] is the percent setting of the harmonic blocking element for OC protection;
[50/51P.I_Rls_HmBlk] is the current setting for releasing the harmonic blocking element;
[50/51P.Opt_Hm_Blk] is the setting for selecting the harmonic blocking criterion;
"Ix " (x: a, b or c) is the fundamental current; "Ix
1
"Imax" is the maximum phase current; "Imax

3.3.6 Heavy Current Blocking Element

If the setting [50P/51P.En_CCE] is set as "1" and any phase current is greater than the setting
[50P/51P.I_CCE] and, the binary output "B09.BO_03" will be blocked. It is always adopted to
cooperate with the overcurrent protection if the circuit breaker has no enough breaking capacity to
cut off the heavy fault current, and the binary output "B09.BO_03" must be configured as tripping
output of the overcurrent protection through the PCS-Explorer. It can prevent the circuit breaker
from being burned if the fault current is greater than the rated breaking current.

3.3.7 Overcurrent Protection Settings

All the settings of the overcurrent protection are listed in following table. For the in formation about
the common explanation of the settings, see Section 7.3.
No. Menu text
1 50/51P.U2_VCE
2 50/51P.Upp_VCE
3 50/51P .En_VCE_CrossCtrl
4 50/51P.RCA
5 50/51P.En_VTS_Blk
PCS-9611 Feeder Relay
> [50/51P.I_Rls_HmBlk]
/Ia | > [50/51P.K_Hm2]
1
/Ib | > [50/51P.K_Hm2]
1
/Ic | > [50/51P.K_Hm2]
1
/Ia | > [50/51P.K_Hm2]
1
The voltage s etting of the negative sequence
voltage blocking element (phase voltage)
The voltage setting of the low voltage blocking
element (phase-to-phase voltage)
The logic setting of the e xternal voltage control
function
The relay characteristic angle for the directional
overcurrent protection
The logic setting of the function which can block
the OC protection related voltage measurement
when the voltage transformer is failed
Date: 2014-04-08
1
2
&
50/51P1.HmBlk_A
3
" (x: a, b or c) is the 2
2
" is the maximum 2
2
Explanation
3 Operation Theory
nd
harmonic current;
nd
harmonic current.
Range
2~70V 0.001V
2~120V 0.001V
0~1 1
-180° ~179° 1°
0~1 1
Step
3-13