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Kyle Form 4C Microprocessor-Based Recloser Control Programming Guide
Sensitive Ground/Earth Fault
Security Limits
Access Factory
Code Write Read Scroll High Low Incr Parameter Settings
120 1 0 YES -- -- -- Sensitive Ground/Earth Fault (ON/OFF) OFF
• The Sensitive Ground/Earth Fault feature allows the
Form 4C control to detect and have the recloser trip
after a selectable, definite time, for ground (zero
sequence) currents below normal ground minimum
trip currents set with Access Code 01 Ground.
• When the Sensitive Ground/Earth Fault feature is
ON, the target display (Access Code 30) is altered to
distinguish between Sensitive Ground/Earth Fault
trips and normal ground fault trips. The ground fault
portion of the display will show an E for Sensitive
Earth Fault operation and G for normal ground fault
operation.
• Remote indication of targets is also altered when the
Sensitive Ground/Earth Fault feature is ON. The
remote targets normally indicate phase A, B, or C
(alternatively 1, 2, or 3 - see access codes 17, 18,
and 19); but with the Sensitive Ground/Earth Fault
feature ON, the remote indications are phase,
ground and sensitive ground in place of A, B, C (1, 2,
or 3), respectively.
• The Sensitive Ground/Earth Fault feature is fully
accessible and independently programmable by a
digital communication link.
Security Limits
Access Factory
Code Write Read Scroll High Low Incr Parameter Settings
121 1 0 YES 100 10 1 Sensitive Ground/Earth Trip Level 100
• Sensitive Ground/Earth Trip Level is set as a per-
centage of programmed ground minimum trip in the
range of 10 to 100% in 1% increments with 3 A* as
the minimum allowable trip value.
• Form 4C control logic will prevent changes in the
percentage settings that would give a trip value
below 3 amps. Under this condition, an LO message
will appear in the display. Subsequent changes to the
Ground/Earth Minimum Trip setting (Access Code 01
Ground) that cause the Sensitive Ground/Earth Trip to
be less than 3 A are not accepted by the control and
an LO message is displayed.
* The minimum allowable trip value is dependent on
the CT ratio (Access Code 10):
2000:1 ratio, the minimum trip value is 6 A
1000:1 ratio, the minimum trip value is 3 A
500:1 ratio, the minimum trip value is 2 A
Security Limits
Access Factory
Code Write Read Scroll High Low Incr Parameter Settings
122 1 0 YES 100 10 1 Alternate Sensitive Trip Level 100
• Alternate Sensitive Trip Level has the same 3 A limi-
tation as the normal Sensitive Trip Level. By pro-
gramming the Alternate Sensitive Ground/Earth Trip
to 100%, the Sensitive Ground/Earth Trip feature is
disabled by the Alternate Minimum Trip Switch on
the control front panel, by selecting supervisory
alternate minimum trip on the Supervisory I/O acces-
sory, or through digital communications.
• Form 4C control logic will prevent changes in the
percentage settings that would give a trip value
below 3 A. Under this condition, an LO message
appears in the display. Subsequent changes to the
Ground/Earth Minimum Trip setting (Access Code 01
Ground) that cause the Sensitive Ground/Earth Trip
to be less than 3 A are not accepted by the control,
and an LO message is displayed.
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