
CHAPTER 5: SETTINGS
CONTROL ELEMENTS
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
5-301
5
Figure 5-161: Thermal overload protection logic
5.8.11.7 Broken conductor detection
SETTINGS
CONTROL ELEMENTS
MONITORING ELEMENTS
BROKEN CONDUCTOR 1(2)
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.
BROKEN CONDUCTOR 1
BROKEN CONDUCTOR 1
FUNCTION: Disabled
Range: Disabled, Enabled
BROKEN CONDUCTOR 1
SOURCE: SRC 1
Range: SRC 1, SRC 2
BROKEN CONDUCTOR 1
I2/I1 RATIO: 20%
Range: 20.0% to 100.0% in steps of 0.1%
BROKEN CONDUCTOR 1
I1 MIN: 0.10 pu
Range: 0.05 to 1.00 pu in steps of 0.01
BROKEN CONDUCTOR 1
I1 MAX: 1.50 pu
Range: 0.05 to 5.00 pu in steps of 0.01
BROKEN CONDUCTOR 1
PKP DELAY: 20.000 s
Range: 0.000 to 65.535 s in steps of 0.001
BROKEN CONDCT 1 BLK:
Off
Range: FlexLogic operand
BROKEN CONDUCTOR 1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
BROKEN CONDUCTOR 1
EVENTS: Disabled
Range: Disabled, Enabled