6
JEP0-IL9558
MVG-A3 Series Earth Fault Overvoltage Relay [Standard: JEC 2520 (2018)]
Features
1. Earth fault overvoltage relay for MPD-3 type ZVT
correspondence.
2. Wide setting range enables 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. Reset method of output contacts can be switchable
between auto-reset and self-hold.
5. The fault value record function is installed.
6. 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.
7. Panel cutout is the same as previous MELPRO-A series
and E series.
Ratings and Specifications
Type name
MVG-A3V-R
MVG-A3V-RD
Style No.
108PGA
523PGA
Ratings
Zero-sequence voltage
7V (MPD-3 type ZVT secondary)
Frequency
50/60Hz (switchable)
Auxiliary power supply
AC110V (Range: 90
～
120V)
Settings
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
(*)
-0.2-0.5-1.0-1.5-2.0-2.5-3.0-4.0-5.0s
Using
condition
Frequency
50Hz(SW1-ON) - 60Hz
(*)
(SW1-OFF)
Output contact
Self-hold(SW2-ON)
–
Auto-reset
(*)
(SW2-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
※
1 "Lo." means LOCK setting (the protection element is locked).
※
2 "In." is the display for instantaneous setting.
Indication item
Range
V
0
measurement
1.0
～
40.0%
Pickup
U.
V
0
setting
Lo.
(
※
1)
,2
～
30%
Operating time setting
In.
(
※
2)
,0.2
～
5.0s
Frequency setting
50,60Hz
Output contact setting
Ho.,FU.
Fault record
2.0
～
40.0%
Clear fault record
O.K.
TEST (Forced operation)
F.O.
Test button
(Forced operation)
By turning the indicator select switch to "TEST" and pushing "TEST" button
for 2 seconds or more, output contact can be forced to operate (except for
the case of LOCK setting).
Power consumption (Power supply)
Normal
：
3.0VA Operating
：
4.0VA
Case
(Munsell color)
Unit-fixed type (Fig. 6-8)
(0.6B7.6/0.2)
Unit-drawer type (Fig. 6-9)
(0.6B7.6/0.2)
Mass
Approx. 0.6kg
Approx. 0.7kg
(*) shows factory setting.
Application to 3.3kV system voltage:
The MPD-3 type ZVT is intended for use at 6.6kV system voltage.
When applied to a system voltage of 3.3 kV, ZVT secondary output voltage at single-phase fault is 3.5V.
(Half of the rating voltage (7V) at 6.6kV system.)
Therefore, setting and measurement display are as follows:
Example 1) In the case of 10% setting for 3.3kV system, the actual setting value should be 5%, which is half
of 10%.
Example 2) When the V
0
measurement display is 5%, the actual value in 3.3kV system is 10% of the single-phase
fault, which is twice the displayed value.
