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5-220
L60 Line Phase Comparison System
GE Multilin
5.6 CONTROL ELEMENTS
5 SETTINGS
5
As long as the current through the voltage monitor is above a threshold (see technical specifications for form-A), the “Cont
Op 1 VOn” FlexLogic™ operand will be set (for contact input 1 – corresponding operands exist for each contact output). If
the output circuit has a high resistance or the DC current is interrupted, the trickle current will drop below the threshold and
the “Cont Op 1 VOff” FlexLogic™ operand will be set. Consequently, the state of these operands can be used as indicators
of the integrity of the circuits in which form-A contacts are inserted.
EXAMPLE 1: BREAKER TRIP CIRCUIT INTEGRITY MONITORING
In many applications it is desired to monitor the breaker trip circuit integrity so problems can be detected before a trip oper-
ation is required. The circuit is considered to be healthy when the voltage monitor connected across the trip output contact
detects a low level of current, well below the operating current of the breaker trip coil. If the circuit presents a high resis-
tance, the trickle current will fall below the monitor threshold and an alarm would be declared.
In most breaker control circuits, the trip coil is connected in series with a breaker auxiliary contact which is open when the
breaker is open (see diagram below). To prevent unwanted alarms in this situation, the trip circuit monitoring logic must
include the breaker position.
Figure 5–122: TRIP CIRCUIT EXAMPLE 1
Assume the output contact H1 is a trip contact. Using the contact output settings, this output will be given an ID name; for
example, “Cont Op 1". Assume a 52a breaker auxiliary contact is connected to contact input H7a to monitor breaker status.
Using the contact input settings, this input will be given an ID name, for example, “Cont Ip 1", and will be set “On” when the
breaker is closed. The settings to use digital element 1 to monitor the breaker trip circuit are indicated below (EnerVista UR
Setup example shown):
The
PICKUP DELAY
setting should be greater than the operating time of the breaker to avoid nuisance
alarms.
Trip coil
52a
UR-series device
with form-A contacts
I = current monitor
V = voltage monitor
DC–
827073A2.CDR
H1a
H1b
H1c
I
V
DC+
NOTE
Summary of Contents for UR series
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Page 12: ...xii L60 Line Phase Comparison System GE Multilin TABLE OF CONTENTS ...
Page 32: ...1 20 L60 Line Phase Comparison System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Page 54: ...2 22 L60 Line Phase Comparison System GE Multilin 2 2 SPECIFICATIONS 2 PRODUCT DESCRIPTION 2 ...
Page 438: ...7 8 L60 Line Phase Comparison System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7 ...
Page 478: ...8 40 L60 Line Phase Comparison System GE Multilin 8 3 FAULT LOCATOR 8 THEORY OF OPERATION 8 ...
Page 502: ...A 10 L60 Line Phase Comparison System GE Multilin A 1 PARAMETER LIST APPENDIXA A ...
Page 584: ...B 82 L60 Line Phase Comparison System GE Multilin B 4 MEMORY MAPPING APPENDIXB B ...
Page 622: ...D 10 L60 Line Phase Comparison System GE Multilin D 1 PROTOCOL APPENDIXD D ...
Page 634: ...E 12 L60 Line Phase Comparison System GE Multilin E 2 DNP POINT LISTS APPENDIXE E ...
Page 642: ...F 8 L60 Line Phase Comparison System GE Multilin F 3 WARRANTY APPENDIXF F ...