8 Maintenance and Inspection
8-6
FVR-C11S-EN
8
[In the case of single-phase input series]
Figure 8-3-1 Diagram for connections of meters
8-4 Insulation
Test
As much as possible, do not test the inverter with a megger because an
insulation test was done at shipping from the factory. If a megger test
must be done, test as described below. If the test method is incorrect,
there is a possibility of damaging the product. Incorrect use of test spec-
ifications for the dielectric strength test may damage products like meg-
ger test. If the dielectric strength test must be conducted, contact your
local distributor or nearest Fuji’s sales office.
1) Megger test for the main circuit
1. Test with a 500V DC megger.
2. If the test voltage is connected to the control circuit, remove all
connection wires to the control circuit.
3. Connect the main circuit terminals using common wires as shown
in Figure 8-4-1
4. Execute a megger test only between the common wire connected
to the main circuit and the ground (terminal
G).
5. If the megger indicates 5M
Ω
or more, it is normal.
(This is the value measured with an inverter only.)
Figure 8-4-1 Megger Test
Inverter
M
V
V
W
A
W
V
V
A
V
V
U
A
U
L2/N
L1/L
N(-)
P(+)
—
+
11
FM
—
U
V
W
+
A
R
V
R
W
R
W
W
W
U
V
3
Motor
Power supply
Inverter
G
G
W
V
U
N(-)
P(+)
P(+)
P1
L2/N
L1/L
Inverter
Megger
