Toshiba GR200 Series Instruction Manual page 562

Dead line detection
2.38.4
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.
Under-voltage relay
(i)
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].
Decision of CB operation
(ii)
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.
Detection time
(iii)
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.
Dead line detection logic
(iv)
Figure 2.38-3 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.
A
UVLG B
C
AB
UVLS
BC
CA
DLDbyUV
From
DLDbyCB
CB decision logic
CB_ALLPH_OPEN
Figure 2.38-3 Dead line detection logic with under voltage relays
(2.84.3)
8000001B60
8100001B61
8200001B62
≥1
&
8400001B63
8500001B64
8600001B65
≥1
&
On
On
&
- 539 -
(2.84.3.2)
(2.84.3.3)
TDLD
&
t 0
&
t 0
0.00 to 3000.00s
6F2S1914 (0.49)
(2.84.3.5)
To Common of DISCAR, DEFCAR
UVLG-A
UVLG-B
UVLG-C
UVLG-AB
UVLG-BC
UVLG-CA
DEAD_LINE_DETECT
To SOTF-OC
8000001B9C
≥1
DEAD_LINE_DETECT
UVLG-OR
UVLG-AND
UVLS-OR
UVLS-AND
GRL200 (Soft 033 & 037)