Toshiba GR 200 Series, Instruction Manual

Page: 438 / 1563

6F2S1915 (0.46)
GRZ200 (Soft 031 & 032)
- 417 -
2.27.4
Dead line detection
The dead line detection (DLD) determinates whether the line is out-of-service or not. Checking
for the voltage existence in three-phase is required when all CBs are closed; hence, the output
signal of the DLD is being checked.
(2.84.3)
(i)
Under-voltage relay
A phase-to-phase (UVLS) element and a phase-to-ground (UVLG) element are provide in the
UV relay. Both elements operate when
On
is set for scheme switch [
DLDbyUV
]. (2.84.3.5)
(ii)
Decision of CB operation
Deciding the dead line state is carried out by examining the CB position. The user should set
On
for the scheme switch [
DLDbyCB
] for the decision. (2.84.3.2)
(iii)
Detection time
The examining period for DLD detection is required to set using the setting [
TDSSV
], the value
of the detection time can be set between 0 to 100 seconds. (2.84.3.3)
(iv)
Dead line detection logic
Figure 2.27-3 shows the scheme logic for the detection of an under voltage condition. It is also
used to determine whether the line is dead or not.
8000001B60
UVLG
A
B
C
&
8100001B61
8200001B62
To SOTF-OC
DEAD_LINE_DETECT
UVLG-OR
≥1
UVLG-AND
8400001B63
UVLS
AB
BC
CA
≥1
8500001B64
8600001B65
UVLS-OR
&
UVLS-AND
t 0
TDLD
&
On
DLDbyUV
&
0.00 to 3000.00s
≥1
t 0
CB_ALLPH_OPEN
On
DLDbyCB
&
8000001B9C
From
CB decision logic
To Common of DISCAR, DEFCAR
UVLG-A
UVLG-B
UVLG-C
UVLG-AB
UVLG-BC
UVLG-CA
DEAD_LINE_DETECT
Figure 2.27-3 Dead line detection logic with under voltage relays