RFL Electronics RFL 9300 - Figure 2-5. Logic Diagram, Weak-Feed Trip (for 2- and 3- Terminal Systems)

a. Local terminal
b. Remote terminal
OR
UHS RECEIVED
FROM REMOTE
TERMINAL
CCD RECEIVED
FROM REMOTE
TERMINAL
AND
AND
AND
AND
NO
NO
NO
YES
YES
YES
YES
NO
WFT RECEIVED
FROM REMOTE
COMPOSITE
FAULT DETECTOR?
(SEE FIG. 2.2)
TRIP
ENABLED
?
LOCAL
CURRENT<1.5A
rms?
COMPOSITE
FAULT DETECTOR?
(SEE FIG. 2.2)
TRIP
AND ISSUE CCT-U
TO REMOTE
TERMINAL
TRIP
AND ISSUE
CCT-U
TO REMOTE
TERMINAL
SEND WFT +
FAULT
DETECTOR
STATUS AT
LOCAL,
TO REMOTE
TERMINAL
SEE NOTE 1
CCD VALUE>
1.5A rms+BIAS
?
NO
YES
SEE NOTE 2
SEE NOTE 1
NOTES: 1. SIGNAL MUST BE VALIDATED FOR THREE TERMINAL SYSTEM.
2. MUST BE COMPOSITE FOR THREE TERMINAL SYSTEM.
CCD VALUE>
3A rms+BIAS
?
NO
YES
BIAS
CONTROL
ENABLED FOR
UNDERGROUND
CABLE ?
NO
YES
Figure 2-5. Logic diagram, weak-feed trip (for 2- and 3- terminal systems)
RFL 9300 RFL Electronics Inc.
October 29, 2001 2 - 18 (973) 334-3100