Toshiba GR200 Series Instruction Manual page 242

Scheme logic
2.9.4
Figure 2.9-3 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.
From ICD
ICD-OR
BCD-2PBlk
+
BCDEN
+
From CTF
CTF_DETECT
BCD-CTFBlk
+
800000EBB0 BCD_BLOCK
Figure 2.9-3 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
present ratio along with the maximum value (I
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
current) on the secondary circuit is larger than 2% of the rated current on
secondary circuit.
Setting
2.9.5
Setting of BCD(Function ID: 452001)
Setting items
BCD-EN
BCD BCD
TBCD
Output BCD-2fBlk
BCD-CTFBlk
BCD-UseFor
8000001C23
BCD
& &
1
&
On
&
1
≥1
Block
/ I ) is displayed only when the current in positive-sequence (or load
2F 1F
Range
1A rating 5A rating
Off / On
0.10 - 1.00
0.00 - 300.00
Non / Block
Non / Block
Trip / Alarm
- 221 -
TBCD
t 0
&
0.00 - 300.00s
Trip
BCD-UseFor
Alarm
+
max) that has been examined for 15 minutes
21
Contents
Unit
- BCD protection scheme switch
- BCD relay operating value (I2/I1)
s BCD operating delay time
- BCD operation block by 2f-detection
- BCD operation block by CTF
- BCD used for trip or alarm
6F2S1915 (0.46)
To Recording
8000001B60
BCD-OPT
To TRC
8300001B23
BCD-OPT-TRIP
&
8400001B62
BCD-OPT-ALARM
&
BCD-ARC-BLOCK
/I ). User can check the
2F 1F
Default
1A
Off
0.20
1.00
Non
Non
Trip
GRZ200 (Soft 031 & 032)
Note
5A