Specifications

Mechanical Indicators
92
Connection and VT ratio of EVT to be combined with a ground voltmeter (LM-11ZNAV or 11-YNAV) and an earth-leakage detector (LM-11NGD)
Generally, an EVT with which the zero-phase tertiary voltage in the 1-wire ground state is 110V (or 190V) is used in a  (star-
star-delta) connection. Although VAf is the input voltage of the ground voltmeter, the respective line voltages of the  connection
are input in addition to Vaf into an earth-leakage detector.
Connection of VT
VT ratio indication examples (in the case of a 6600V circuit)
Type of EVT
1-phase EVT
(without tertiary winding)
1-phase EVT
(with tertiary winding)
3-phase EVT
(with tertiary winding)
1-phase EVT
(without tertiary winding)
When the zero-phase tertiary voltage
in the 1-wire ground state is 110V
/ V
/ / V
6600 / 110 / V
/ 110V
When the zero-phase tertiary voltage
in the 1-wire ground state is 190V
/ V
/ / V
6600 / 110 / V
/ 190V
Without tertiary winding With tertiary winding
When the EVT is connected between the transformer neutral point and the earth
6600
3
110
3
6600
3
110
3
110
3
110
3
6600
3
6600
3
190
3
6600
3
110
3
190
3
190
3
6600
3
Vaf
6600V
6600V
Vaf
6600V
Vaf
Note.
With an arrangement without the tertiary winding in the above diagram, the voltage at the open end resulting from a secondary winding is considered as the zero-phase tertiary voltage.
Scales of a ground voltmeter (LM-11ZNAV or 11-YNAV) and an earth-leakage detector (LM-11NGD) and the VT ratio
The earth-leakage detector is used in combination with an -connected EVT, and this table shows the relationship between the
line voltage V
L-L and the scale and the VT ratio.
Circuit voltage
V
V
L—L
440
3300
6600
VT ratio (examples)
440
3
110
3
440
3
190
3
440
3
110
3
440
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
110
3
190
3
3300
3
3300
3
3300
3
3300
3
6600
3
6600
3
6600
3
6600
3
3300
3
3300
3
3300
3
3300
3
6600
3
6600
3
6600
3
6600
3
440
3
Indicator maximum
scale value
(V)
600
440
4500
3300
9000
6600
Zero-phase voltage
(Vaf)
110
190
110
190
110
190
110
190
110
190
110
190
When three 1-phase EVTs are used
When one 3-phase EVT is used
With tertiary winding
440 / 110 /
440 / 110 /
440 / 110 /
440 / 110 /
3300 / 110 /
3300 / 110 /
3300 / 110 /
3300 / 110 /
6600 / 110 /
6600 / 110 /
6600 / 110 /
6600 / 110 /
With tertiary winding
/ /
/ /
/ /
/ /
/ /
/ /
/ /
/ /
/ /
/ /
/ /
/ /
Without tertiary winding
/
/
/
/
/
/
/
/
/
/
/
/
LM-11ZNAV LM-11YNAV
Indicator rating (V)
When 3 units are combined
86.6
150
63.5
110
86.6
150
63.5
110
86.6
150
63.5
110
In the case of 1 unit
150
259
110
190
150
259
110
190
150
259
110
190
LM-11NGD
Indicator rating
(V)
86.6
150
63.5
110
86.6
150
63.5
110
86.6
150
63.5
110
Alarm relay operating
voltage (V)
30~50
55~75
30~50
55~75
30~50
55~75
30~50
55~75
30~50
55~75
30~50
55~75
110
3
440
3
110
3
440
3
110
3
440
3
110
3
110
3
110
3
110
3
110
3
110
3
110
3
110
3
110
3
 There are two types of indicator maximum scale values, the nominal line
voltage VL-L and 1.36✕VL-L. (1.36 is the value in the case of 150V/110V.)
 The zero-phase voltage Vaf is the voltage at the open end of the open 
connection when the primary side is in the 1-wire ground state.
 The alarm relay operation voltage is related only to the zero-phase voltage
(that is, the VT ratio) and has no relationship with the indicator scale.
Regarding the indicator rating
 In the case of combining three LM-11ZNAV (LM-11YNAV) units or in the case of
LM-11NGD - The indicator rating is the line voltage at the  connection side when
the primary side is in the 1-wire ground state (however, the fault phase is excluded).
 In the case of using one LM-11ZNAV (LM-11YNAV) unit - The indicator rating is the
voltage corresponding to the zero-phase voltage Vaf.