Toshiba GR200 Series Instruction Manual page 38

Selection of protection-characteristic
2.1.2
The DIF function has three protection-characteristics and one of them is selected by scheme
switch [DIFTP-FORM] under replica setting
items in Table 2.1-3.
 Check-zone and discriminating-zone -protection
A bus-bar is protected by both a "check-zone-protection" and a "discriminating-zone-
protection"; a tripping command is transmitted the corresponding CH in the faulted
zone when both protections operate.
Having a "Check-zone" and a "discriminating-zone-protection" is recommended for
all bus-bar systems and this provides a very secure and selective protection.
 Check-zone-protection
A bus-bar is protected by a "check-zone-protection"; the tripping command is
transmitted to all CHs within the Check-zone.
A "Check-zone-protection" can be applied alone in the case of a single bus-bar
system with a single zone; the setting of the 'Discriminating-zone-protection' is not
available when the scheme 'Check-zone-protection' is used alone in DIF.

Discriminating zone protection
A bus-bar is protected by a "discriminating-zone-protection"; the tripping command
transmitted to all CHs that correspond to the faulted zone.
Note: Replica setting is discussed separately. Generally, the system integrator will
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perform the replica setting before shipment to the end user.
Note: Both a 'Check-zone-protection' and 'Discriminating-zone-protection' are used when
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two IEDs are used to protect a duplicated bus-bar protection system; the user
should set one IED for the scheme 'Check zone protection' and the other IED for
the scheme 'Discriminating zone protection'.
. The scheme switch is tabulated with other setting
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6F2S1931 (0.20)
Centralized GRB200
(Soft: 030, 031, 032, 033, 034)