Toshiba GR200 Series - 2.35.1 VCHK1 for 1 CB system; (i) Characteristic and elements; (ii) Voltage condition and check zone

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
- 476 -
2.35.1 VCHK1 for 1CB system
(i) Characteristic and elements
VCHK1 does voltage and synchronous check in 1CB system. Four relay elements (OVB, OVB,
UVL, and UVL) are used for voltage check. Tow relay elements (OVB and OVL) are used for
verification of existing voltage; the remaining ones (UVB and UVL) are used for verification of
non-existing voltage.
(ii) Voltage condition and check zone
Figure 2.35-2 shows four zones (A1 to D1) for voltage verification. For example, if both UVB
and OVL elements are active, VHCK1 determines that the Bus-bar is in Dead condition (no-
voltage) and Line is in Live condition (existing voltage). This condition holds true for A1 zone.
If voltage condition matches with B1 zone, synchronous check is carried out on VCHK1. Thus,
this means that Synchronous check is not carried out in A1, C1 or D1 zones.
C1
D1
B1
A1
0(V)
VCHK-UVL
VCHK-OVL
A1, C1, D1: Voltage check
B1: Synchronism check
VCHK-UVB VCHK-OVB
V
L
Line voltage
(Incoming voltage)
V
B
Bus-bar voltage
(Running voltage)
Dead bus and
dead line
(DB-DL)
Dead bus and
live line
(DB-LL)
Live bus and
live line
(LB-LL)
Live bus and
dead line
(LB-DL)
Figure 2.35-2 Check zones by VCHK1
Table 2.35-2 Voltage condition by VCHK1
Voltage condition
DB_LL
LB_LL
DB_DL
LB_DL
Check zone
A1
B1
C1
D1
Bus-bar voltage (V
B
)
Dead
Live
Dead
Live
Line voltage (V
L
)
Live
Live
Dead
Dead