GE L30 Instruction Manual page 511

CHAPTER 5: SETTINGS CONTROL ELEMENTS
voltage level without disturbance in current can indicate VT fuse fail conditions. These noted indications of fuse failure can
also be present when faults are present on the system, so a means of detecting faults and inhibiting fuse failure
declarations during these events is provided.
Once the fuse failure condition is declared, it is sealed-in until the cause that generated it disappears.
An additional condition is introduced to inhibit a fuse failure declaration when the monitored circuit is de-energized;
positive-sequence voltage and current are both below threshold levels.
— Enables and disables the fuse failure feature for Source 1 VT Fuse Fail.
VT FUSE FAILURE 1 FUNCTION
— Enables and disables the VT neutral wire open detection function. When the VT is
NEUTRAL WIRE OPEN 1 DETECTION
connected in Delta, do not enable this function because there is no neutral wire for Delta connected VT.
— Specifies the pickup level of 3rd harmonic of 3V0 signal for the
NEUTRAL WIRE OPEN 1 3 HRAM PKP NEUTRAL WIRE OPEN
logic to pick up.
DETECTION
Base voltage for this element is setting in the case of WYE VTs and ( )/ in case
PHASE VT SECONDARY PHASE VT SECONDARY
of DELTA VTs. The setting is found under .
SETTINGS  SYSTEM SETUP  AC INPUTS  VOLTAGE BANK  PHASE VT SECONDARY
Figure 5-159: VT fuse fail logic
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L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 5-297