Setting Of Ground Fault Protection Characteristics - Mitsubishi Electric V Series Instruction Manual

17.2 Setting of ground fault protection characteristics

1
GF
Ig
(xln)
.5
Ig
.3 .7
.5
Tg
.1 .9 .8
1.5
1
GF Freq.
TRIP
50Hz 60Hz
TEST
.84
.76 .92
.68 1
1.15
(OVER)
Ip
(xlu)
(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.
No. Setting item Mark
1 GF pick-up current Ig
2 GF time Tg
̶
̶ Alarm output
(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%.
2
Tg
(s)
.1
.15 .1
.3 .15
.3
.5
.8
3 1.5
3
ALARM
RESET
TEST
L/S LOCK
Adjustable setting range
0.1 to 1.0 × In (0.1 steps)
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
(TRIP)
Setting for TRIP: Self-holding/Setting for ALARM: Automatic reset
Option
Ground fault protection characteristic curve
60
50
40 Ground fault pick-up current: lg
In × 0.1-1.0 ±20% (step 0.1)
30
20
10
1.0
0.1
5
4
3
3.0
2
Ground fault time: Tg (Note)
1
0.1-0.15-0.3-0.5-0.8-1.5-3.0 (s) ±20%
.5
.4
0.3
.3
.2
.1 0.1
.05
.04
.03
.02
10 20 50 100125 150 200
Ground fault current (% of CT rating ln)
(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%.
(ALARM)
(at 1.5 × Ig)
1
50
40
30
20
10
5
4
3
2
(s)
1
.5
.4
.3
.2
.1
.05
.04
.03
.02
500 1000
Factory
Accuracy
default value
±20% 1.0
±20%
3 s (TRIP)
(Note)
Setting for TRIP
̶
(Self-holding)
E-35