Toshiba GR200 Series - 2.19.4 Scheme logic; 2.19.5 Setting

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 289 -
2.19.4 Scheme logic
Figure 2.19-3 shows the scheme logic for the BCD function. The BCD function issues a trip
signal through a delayed pick-up timer, the value of which is set for [TBCD]. The operation of
the BCD function can be disabled using scheme switch [BCD-EN] Off.
BCD
BCD-OPT
TBCD
0.00 - 300.00s
t
0
Block
BCD-CTFBlk
+
800000EBB0 BCD_BLOCK
8000001C23
&
8000001B60
&
Alarm
Trip
BCD-UseFor
+
8300001B23
8400001B62
BCD-OPT-TRIP
BCD-OPT-ALARM
BCD-ARC-BLOCK
On
BCDEN
+
ICD-OR
From ICD
&
BCD-2PBlk
CTF_DETECT
From CTF
&
1
≥1
&
&
&
+
1
To TRC
To Recording
Figure 2.19-3 Broken conductor protection scheme logic
Normal power system levels of negative phase sequence restrict the setting value of
[BCD]. The BCD function continuously determines the ratio (I
2F
/I
1F
). User can check the
present ratio along with the maximum value (I
21
max) that has been examined for 15 minutes
ago. We recommend that user should distinguish the present ratio against the value on
commissioning stage; and user should set a value for [BCD] from 130% to 150% of the ratio has
been checked.
Note: The ratio (I
2F
/ I
1F
) is displayed only when the current in positive-sequence (or load
current) on the secondary circuit is larger than 2% of the rated current on
secondary circuit.
2.19.5 Setting
Setting of BCD(Function ID: 452001)
Setting items
Range
Unit
Contents
Default
Note
1A rating
5A rating
1A
5A
BCD-EN
Off / On
-
BCD protection scheme switch
Off
BCD
BCD
0.10 - 1.00
-
BCD relay operating value (I2/I1)
0.20
TBCD
0.00 - 300.00
s
BCD operating delay time
1.00
Output
BCD-2fBlk
Non / Block
-
BCD operation block by 2f-detection
Non
BCD-CTFBlk
Non / Block
-
BCD operation block by CTF
Non
BCD-UseFor
Trip / Alarm
-
BCD used for trip or alarm
Trip