GE L60 Instruction Manual page 482

CONTROL ELEMENTS
The open pole detector is intended to identify an open pole of the line circuit breaker. The scheme monitors the breakers
auxiliary contacts, current in the circuit, and optionally voltage on the line. The scheme generates output operands used to
block the phase selector and some specific protection elements, thus preventing maloperation during the dead time of a
single-pole autoreclose cycle or any other open pole conditions.
The scheme declares an open pole at the moment a single-pole trip is issued.
In two-breaker and breaker-and-a-half applications, an open pole condition is declared when one or more of the following
hold:
• Both breakers have an open pole on the same phase
• The current on the line drops below a threshold
• The current and voltage on the line drop below a threshold
The open pole feature uses signals defined by the
setting. Voltage supervision can be used only with wye VTs on the line side of the breaker.
SOURCE
OPEN POLE CURRENT PICKUP
OPEN POLE LINE XC1
net capacitive reactance of the line and the reactors installed between the line breakers. The value is entered in secondary
5
ohms. This setting is relevant if open pole condition at the remote end of the line is to be sensed and utilized by the relay.
OPEN POLE LINE XC0
capacitive reactance of the line and the reactors installed between the line breakers. Do not enter the value in secondary
ohms. This setting is relevant if open pole condition at the remote end of the line is to be sensed and utilized by the relay
(OPEN POLE REM OP
OPEN POLE REM CURR PKP
compensated by the calculated charging current. The latter is calculated based on the local voltages and the capacitive
reactances of the line. This setting is relevant if open pole condition at the remote end of the line is to be sensed and
utilized by the relay
— Selects the mode of operation of the open pole function. When the "Accelerated" mode is chosen, an
OPEN POLE MODE
open pole is declared ½ cycle after trip output operation and before the breaker pole opens. This blocks distance loops
involved in the faulted phase and phase selector, and arms the trip output to produce three-pole trip for the next fault. If
the fault evolves into multi-phase fault before breaker pole opens for the first fault, the remaining in-service distance loops
initiates a three-pole trip. When the "Traditional" mode is selected, then an open pole is declared only after the breaker
opens and current disappears. If the fault evolves into a multi-phase fault before the circuit breaker pole opens for the first
fault, the phase selector changes the fault type from a single-line-to-ground fault to a multi-phase fault, thereby initiating
a three-pole trip.
OPEN POLE DETECTION
selected, the breaker 52 contacts and the current with optional voltage signals are used to determine open pole
conditions. For the "I AND V only" selection, only the current with optional voltage signals are used.
For convenience, the position of the breaker poles defined in the breaker control feature and available as FlexLogic
operand
BREAKER 1
AND CBaux" detection value is selected.
For correct operation of the open pole detector, the breaker control, trip output, and single-pole autoreclose features must
be enabled and configured properly. When used in configuration with only one breaker, set the
"Enabled" and the
5-314
OPEN POLE DETECTION:

I AND V AND CBaux
OPEN POLE TARGET:

Self-Reset
OPEN POLE EVENTS:

Disabled
— This setting establishes the current threshold below which an open pole is declared.
— Specifies positive-sequence reactance of the entire line. If shunt reactors are applied, this value is a
— Specifies zero-sequence reactance of the entire line. If shunt reactors are applied, this value is a net
FlexLogic operand).
— Specifies pickup level for the remote-end current estimated by the relay as the local current
(OPEN POLE REM OP FlexLogic operand).
— Selects the signals used to detect an open pole condition. When "I AND V AND CBaux" value is
through
Φ A CLSD BREAKER 1 Φ
setting to "On" (see the Breaker Control section earlier in this chapter for details).
BREAKER 2 OUT OF SV
Range: I AND V AND CBaux, I AND V only
Range: Self-Reset, Latched, Disabled
Range: Enabled, Disabled
GROUPED ELEMENTS  SETTING GROUP 1(6)  DISTANCE  DISTANCE
and are used by the open pole feature if the "I AND V
C CLSD BREAKER 1 OOS
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
to
BREAKER 2 FUNCTION