GE D90 Plus Instruction Manual page 166

DIRECT INPUTS AND OUTPUTS
156
Figure 129: Interlocking busbar protection scheme example
For increased reliability, a dual-ring configuration is recommended for this application,
shown as follows.
Figure 130: Interlocking busbar protection scheme via direct inputs and outputs
The following settings are applied to implement this application. For IED 1, set the inter-
relay application for both channels as follows in the Settings > Communications > Inter-
Relay menu. If there are more than two IEDs in a ring configuration, then one device (for
example, IED 1) must have its protocol encoding set as an internal clock and the remaining
devices have their protocol encoding set as external clock if no multiplexer is used.
Figure 131: Inter-relay communications settings for IED 1
For IEDs 2 through 4, set the inter-relay application for both channels as follows in the
Settings > Communications > Inter-Relay menu.
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: COMMUNICATIONS