6
JEP0-IL9554
MDG-A3 Series Directional Earth Fault Relay [Standard: JIS C 4609 (1990)]
Features
1. Directional earth fault relay for MPD-3 type ZVT
correspondence.
2. Wide setting range and fine setting steps enable
flexible protection coordination.
3. The number of connectable relay units to MPD-3 type
ZVT is increased to 20.
Caution
However, this increase is limited only when all
of the relays are composed of New MELPRO-A series. If
another series are combined, the number of connectable
units is limited to 5.
4. Max. 20 relays can be connected through V0 extension
terminal.
5. Reset method of output contacts can be switchable
between auto-reset and self-hold.
6. The fault value record function is installed.
7. Good operability and visibility design is adopted.
The numerical display turns on for 3 seconds when the
setting value is changed, which enables to check
setting values easily.
8. Panel cutout is the same as previous MELPRO-A series
and E series.
Ratings and Specifications
Type name
MDG-A3V-R
MDG-A3V-RD
Style No.
104PGA
519PGA
Ratings
Zero-sequence current
0.2A (MZT type ZCT primary)
Zero-sequence voltage
7V (MPD-3 type ZVT secondary)
Frequency
50/60Hz (switchable)
Auxiliary power supply
AC110V (Range: 90
～
120V)
Settings
I
0
Operation value
0.1
(*)
-0.2-0.4-0.6-0.8-1.0A (ZCT primary value)
V
0
Operation value
LOCK
(*)
-2-2.5-3-4-5-6-7-7.5-8-9
–
10%
(Single-phase fault in 6.6kV power systems:
V
0
primary = 3810V, ZVT secondary = 7V)
Operating time
Instantaneous
(*)
-0.2-0.3-0.4-0.5-0.6-0.7-0.8-0.9-1.0s
Using
condi
tion
Frequency
50Hz(SW1-ON) - 60Hz
(*)
(SW1-OFF)
Output contact
Self-hold(SW2-ON)
–
Auto-reset
(*)
(SW2-OFF)
Max. sensitivity
angle
Lead 10
°
(SW3-ON)
–
Lead 45
°
(*)
(SW3-OFF)
Display
Self-monitoring
The "RUN" indicator (green-color) is lighted in normal condition.
Operation indicator
The indicator turns from black into orange color when the protection element
is put into operation. (Manual resetting type)
Numerical display
Indication item
Range
V
0
measurement
1.0
～
12.0%
I
0
measurement
0.05
～
0.09A, 0.1
～
1.5A
Phase measurement
0
～
359
°
(V
0
standard, I
0
lag display)
V
0
, I
0
Pickup
U.-I.
V
0
setting
Lo.
(
※
1)
,2.0
～
10%
I
0
setting
0.1
～
1.0A
Operating time setting
In.
(
※
2)
,0.2
～
1.0s
Condition setting
Frequency, output contact, and max.
sensitivity angle are shown at intervals
of 2 seconds.
Fault record of V
0
2.0
～
40.0%
Fault record of I
0
0.1
～
1.5A
Fault record of phase
0
～
359
°
(V
0
standard, I
0
lag display)
Clear fault record
O.K.
TEST (Forced operation)
F.O.
※
1 "Lo." means LOCK setting (the protection element is locked).
※
2 "In." is the display for instantaneous setting.
