GE b30 Instruction Manual page 347

CHAPTER 5: SETTINGS
Six instantaneous overcurrent elements facilitate applications including an external check zone function. For bus
configurations of up to five feeders, each with a second set of CTs, a check zone can be implemented by externally
summing currents from the independent sets of CTs and connecting the resulting differential current to the sixth current
input. In this case, one element monitors the independently formed differential current and supervises the differential
protection.
If applied, the overcurrent function responding to the independently formed differential signal is used to supervise the
output from the main differential protection with a FlexLogic AND gate before driving the output contact. It is not
recommended to use the drop-out operand of the overcurrent function as the block input to the differential element. The
differential element includes the saturation detector that responds to specific time relationships between the differential
and restraining currents, and therefore, it must be operational all the time in order to function properly.
The phase instantaneous overcurrent element can be used as an instantaneous element with no intentional delay or as a
definite time element. The input current is the fundamental phasor magnitude. For timing curves, see the publication
Instantaneous Overcurrent (IOC) Element Response to Saturated Waveforms in UR Series Relays (GET-8400A).
— This setting enables and disables the phase instantaneous overcurrent protection element.
FUNCTION
— Selects the signal source for the phase instantaneous overcurrent protection element.
SOURCE
— Specifies the phase instantaneous overcurrent pickup level in per-unit values.
PICKUP
—Delays the assertion of the
DELAY
and relays.
— Specifies a delay for the reset of the phase instantaneous overcurrent element between the operate output
RESET DELAY
state and the return to logic 0 after the input passes outside the defined pickup range. This setting is used to ensure that
the relay output contacts are closed long enough to ensure reception by downstream equipment.
— Assertion of the operand assigned to this setting block's phase A of the phase instantaneous overcurrent
BLOCK A
element.
— Enables and disables the logging of phase instantaneous overcurrent events in the sequence of events recorder.
EVENTS
5.7.4.5 Phase directional overcurrent (ANSI 67P, IEC PDOC/PTOC)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  PHASE CURRENT  PHASE DIRECTIONAL 1(2)
 PHASE
 DIRECTIONAL 1
B30 BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
operands. It is used to achieve timing coordination with other elements
PHASE IOC OP
Figure 5-89: Phase instantaneous overcurrent 1 logic
PHASE DIR 1

FUNCTION: Disabled
PHASE DIR 1 SIGNAL

SOURCE: SRC 1
PHASE DIR 1 BLOCK:

Off
GROUPED ELEMENTS
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
Range: FlexLogic operand
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