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N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
GROUPED ELEMENTS
CHAPTER 5: SETTINGS
5
The open pole detector detects if any pole of the associated circuit breaker is opened or the conductor is broken on the
protected power line and cable. The output FlexLogic operands can be used in three-pole and single-pole tripping
schemes, in reclosing schemes, in blocking some elements (like CT failure), and in signaling or indication schemes. In
single-pole tripping schemes, if
OPEN POLE
flag is set, any other subsequent fault causes a three-phase trip regardless of
fault type.
The open pole detector logic detects absence of current in one phase during presence of current in other phases. Phases
A, B, and C breaker auxiliary contacts (if available) are used in addition to make a logic decision for single-pole tripping
applications. If voltage input is available, a low voltage function is used to detect absence of the monitoring voltage in the
associated pole of the breaker.
OPEN POLE FUNCTION
— Used to enable/disable operation of the element.
OPEN POLE BLOCK
— Selects a FlexLogic operand that blocks operation of the element.
OPEN POLE CURRENT SOURCE
— Selects the source for the current for the element.
OPEN POLE CURRENT PICKUP
— Selects the pickup value of the phase current. The pickup setting is the minimum of the
range and likely to be somewhat above of the charging current of the line.
OPEN POLE BROKEN CONDUCTOR
— Enables and disables detection of broken conductor or remote pole open conditions.
OPEN POLE VOLTAGE INPUT
— Enables and disables the voltage input in making a logical decision. If the line VT (not bus VT) is
available, the voltage input can be set to “Enable.”
OPEN POLE VOLTAGE SOURCE
— Selects the voltage source for the element.
OPEN POLE
φ
A(C) AUX CONTACT
— These three settings are used to select a FlexLogic operand reflecting the state of the 52b
type phase A circuit breaker auxiliary contact (closed when main breaker contact is open) for single-pole tripping
applications. If two breakers per line are used, then both breaker auxiliary contacts feeding into the AND gate
(representing auxiliary contacts connected in series) are to be assigned.
OPEN POLE PICKUP DELAY
— Selects the pickup delay of the element.
OPEN POLE RESET DELAY
— This setting is used to select the reset delay of the element. The use of this setting depends on
the particular application and whether single-pole or three-pole tripping is used. It comprises the reset time of the
operating elements it used in conjunction with, the breaker opening time, and breaker auxiliary contacts discrepancy with
the main contacts.
OPEN POLE RESET
DELAY: 0.100 s
Range: 0.000 to 65.535 s in steps of 0.001
OPEN POLE TARGET:
Self-reset
Range: Self-reset, Latched, Disabled
OPEN POLE EVENTS:
Disabled
Range: Disabled, Enabled