GE L30 Instruction Manual page 515

CHAPTER 5: SETTINGS
5.8.11.7 Broken conductor detection
SETTINGS  CONTROL ELEMENTS  MONITORING ELEMENTS  BROKEN CONDUCTOR 1(2)
 BROKEN CONDUCTOR 1

The broken conductor function detects a transmission line broken conductor condition or a single-pole breaker
malfunction condition by checking the phase current input signals and the I_2 / I_1 ratio. The intent is to detect a single-
phase broken conductor only. As such, two-phase or three-phase broken conductors cannot be detected.
To distinguish between single-phase disappearance and system disturbance in all three phases (such as load change and
switching), the broken conductor element monitors the change in all three phase currents at the present instance and at
four cycles previous. It also monitors changes in the I_2 / I_1 ratio, I_1 minimum, and I_1 maximum.
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
Figure 5-161: Thermal overload protection logic
BROKEN CONDUCTOR 1

FUNCTION: Disabled
BROKEN CONDUCTOR 1

SOURCE: SRC 1
BROKEN CONDUCTOR 1

I2/I1 RATIO: 20%
BROKEN CONDUCTOR 1

I1 MIN: 0.10 pu
BROKEN CONDUCTOR 1

I1 MAX: 1.50 pu
BROKEN CONDUCTOR 1

PKP DELAY: 20.000 s
BROKEN CONDCT 1 BLK:

Off
BROKEN CONDUCTOR 1

TARGET: Self-reset
BROKEN CONDUCTOR 1

EVENTS: Disabled
Range: Disabled, Enabled
Range: SRC 1, SRC 2
Range: 20.0% to 100.0% in steps of 0.1%
Range: 0.05 to 1.00 pu in steps of 0.01
Range: 0.05 to 5.00 pu in steps of 0.01
Range: 0.000 to 65.535 s in steps of 0.001
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
CONTROL ELEMENTS
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