GE Multilin 850 Instruction Manual page 503

CHAPTER 4: SETPOINTS
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 4-159: Transfer Scheme - Bus Tie Breaker logic diagram
After the lost source has been re-established, there are three methods to restore the
system to normal configuration. Two methods are manual and one is automatic:
• Manual Method 1 - when the sources cannot be synchronized: The Bus Tie Breaker
must be manually opened before the open incomer can be manually closed. In this
procedure the incomer is allowed to close only if the incoming source (Line VT) voltage
is above a live threshold and the load (Bus VT) voltage is below a dead threshold value
(setpoints for voltage check - dead sources associated with the Synchrocheck
function must be set).
CONTROL
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