Broken Conductor - GE F650 Instruction Manual

5.5 CONTROL ELEMENTS
5
F650 incorporates a broken or fallen conductor detection function. The relay uses the ratio between the negative sequence
current, I , and the positive sequence current I
2
load fault conditions, an unbalance is produced and this ratio increases.
Setpoint > Control Elements > Broken Conductor
Table 5–86: BROKEN CONDUCTOR ELEMENT SETTINGS
SETPOINT > CONTROL ELEMENTS > BROKEN CONDUCTOR
SETTING DESCRIPTION
Function permission
Tap Level in percentage of I2/I1
Trip Time
Snapshot event generation
Current Inhibition Level setting
This way, when the function is enabled and the unbalance is produced over the set percentage, the element will pick up. If
unbalance conditions are maintained during a period longer than the set time delay, the element will trip.
In order to avoid trips or pickups with very weak loads there is a current level threshold to inhibit the operation of the
element when the three phase currents are below a fixed level.
Note: The I2/I1 current inhibition level for the different firmware versions is as follows:
FIRMWARE VERSION
1.50 or Lower
1.60 or Higher
1.80 or Higher
5-108
Figure 5–30: FUSE FAILURE ELEMENT BLOCK DIAGRAM
. In normal and balanced load situations, this ratio is zero, while in severe
1
NAME
Function
Tap
Trip Delay
Snapshot Events
Operation Threshold
CURRENT INHIBITION LEVEL
10 mA
50 mA
Selectable by setting from 0.000 to 1.000 in steps of 0.001 A
F650 Digital Bay Controller

5.5.8 BROKEN CONDUCTOR

DEFAULT VALUE STEP RANGE
DISABLED N/A [DISABLED – ENABLED]
20.0 0.1% [20.0 : 100.0]
60.00 0.01 s [0.00 : 900.00]
ENABLED N/A [DISABLED – ENABLED]
0.005 0.001 A [0.000 : 1.000]
5 SETTINGS
GEK-106310AB