GE L60 Instruction Manual page 473

CHAPTER 5: SETTINGS
Consider the following configuration:
The source 1 (SRC1) phase currents are CTs and phase voltages are bus VTs. The source 2 (SRC2) phase voltages are line
VTs. Contact input 1 is set as the breaker 52a contact (optional).
The conditions prior to flashover detection are:
• ΔVA is greater than pickup
• IA, IB, IC = 0; no current flows through the breaker
• 52a status = 0 (optional)
The conditions at flashover detection are:
• ΔVA is less than pickup
• VAg, VBg, or VCg is lower than the pickup setting
• IA, IB, or IC is greater than the pickup current flowing through the breaker
• 52a status = 0 (optional)
The element operates only when phase-to-ground voltages are connected to relay terminals. The flashover
element does not operate if delta voltages are applied.
Settings
— This setting specifies a signal source used to provide three-phase voltages and three-phase
BRK 1 FLSHOVR SIDE 1 SRC
currents from one side of the current breaker. The source selected as a setting and must be configured with breaker phase
voltages and currents, even if only three VTs are available across the breaker.
— This setting specifies a signal source used to provide another set of three phase voltages
BRK 1 FLSHOVR SIDE 2 SRC
whenever six VTs are available across the breaker.
to
BRK 1 STATUS CLSD A BRK 1 STATUS CLSD C
breaker. A separate FlexLogic operand can be selected to detect individual breaker pole status and provide flashover
detection. The recommended setting is 52a breaker contact or another operand defining the breaker poles open status.
— This setting specifies a pickup level for the phase voltages from both sides of the breaker. If six VTs
BRK 1 FLSHOVR V PKP
are available, opening the breaker leads to two possible combinations – live voltages from only one side of the breaker, or
live voltages from both sides of the breaker. Either case sets the scheme for flashover detection upon detection of voltage
above the selected value. Set
— This setting specifies a pickup level for the phase voltage difference when two VTs per phase
BRK 1 FLSHOVR DIFF V PKP
are available across the breaker. The pickup voltage difference should be below the monitored voltage difference when
close or open breaker resistors are left in service. The setting is selected as primary volts difference between the sources.
— This setting specifies the normal load current which can flow through the breaker. Depending on
BRK 1 FLSHOVR AMP PKP
the flashover protection application, the flashover current can vary from levels of the charging current when the line is de-
energized (all line breakers open), to well above the maximum line (feeder) load (line/feeder connected to load).
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
— These settings specify FlexLogic operands to indicate the open status of the
to 85 to 90% of the nominal voltage.
BRK FLSHOVR V PKP
CONTROL ELEMENTS
5
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