Toshiba GR200 Series Instruction Manual page 277

VCT combinations
4.2.6
In the preceding section we have discussed about three types of the VCT modules. The selection
of the VCT types in the MainUnit and the SubUnit are controlled with three structures, which
we can categorized by means of the number of CTs and VTs
No VT configuration (voltage-transformer not existing for fail-safe)
(i)
When the fail-safe function halts for the protection, a voltage-transformer (VT) is not required
to acquire voltage quantities. Figure 4.2-8 illustrates the 24 CH arrangement; a CH will collect
the three-phase currents, which corresponds coincidentally with the reception signal number
(CH1) of the VCT module. This arrangement is ruled when both the MainUnit and the SubUnit
have the VCT23B.
Busbar 1
Busbar 2
I a,b,c I a,b,c
VT configuration for two-zones protection
(ii)
Figure 4.2-9 shows the 20 CH arrangement; two protection zones is protected with 22 CTs plus
two VTs. This configuration is achieved when the MainUnit has the VCT48B, but the SubUnit
has the VCT23B.
I a,b,c
Figure 4.2-8 Busbar protection
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I a,b,c I a,b,c
Centralized GRB200
(Soft: 030, 031, 032, 033, 034)
6F2S1931 (0.20)