E-35
ENGLISH
17.2 Setting of ground fault protection characteristics
(Note)
When the 3-pole circuit breaker is used
on a 3-phase 4-wire system, the N-pole
CT (NCT) is required for ground fault
protection.
For the specifications, refer to the catalog.
For the NCT installation, refer to the in-
struction manual included in the product.
When the ground fault pick-up current
(Ig) is 0.1, the control power supply is
required.
Option
3-1.5-0.8-0.5-0.3-0.15-<0.1 - <0.1-0.15-0.3-0.5-0.8-1.5-3 s
No.
Adjustable setting range
0.1 to 1.0
×
In (0.1 steps)
Setting for TRIP: Self-holding/Setting for ALARM: Automatic reset
(Note) When Tg = 0.1 setting, operating time is 0.1 s
±
50%.
When
Tg
=
0.15 setting, operating time is 0.15 s
±
30%.
(at 1.5
×
Ig)
Accuracy
±
20%
±
20%
(Note)
Factory
default value
1.0
3 s (TRIP)
Setting for TRIP
(Self-holding)
Setting item
GF pick-up current
GF time
Alarm output
(TRIP)
(ALARM)
1
2
̶
Mark
Ig
Tg
̶
̶
Operating time (s)
Ground fault current (% of CT rating ln)
0.1
0.3
3.0
0.1
1.0
60
50
40
30
20
10
5
4
3
2
1
.5
.05
.04
.03
.02
.4
.3
.2
.1
(s)
50
40
30
20
10
.5
.05
.04
.03
.02
.4
.3
.2
.1
1
5
4
3
2
1
10
20
50
100125 150 200
500
1000
Ground fault time: Tg (Note)
0.1-0.15-0.3-0.5-0.8-1.5-3.0 (s)
±
20%
Ground fault pick-up current: lg
In
×
0.1-1.0
±
20% (step 0.1)
(Note) When Tg = 0.1 setting, operating time is 0.1 s
±
50%.
When
Tg
=
0.15 setting, operating time is 0.15 s
±
30%.
Ground fault protection characteristic curve
1.15
(xlu)
1
.92
(OVER)
TEST
TRIP
ALARM
(s)
L/S LOCK
.84
.76
.68
1
.9
3
3
1.5
1.5
.15
.15
.1
.1
.8
.8
.5
.5
.3
.3
.7
.5
.3
.1
RESET
Tg
Tg
(xln)
Ig
Ig
Ip
TEST
Freq.
50Hz
60Hz
GF
GF
1
2
