Mitsubishi Electric Melsec Q Series User Manual page 117

9 Troubleshooting
9.2.3 If electric energy cannot be measured
The following check has to be performed while current is flowing from the power source side to
the load side.
"MEA." LED "R" LED
OFF OFF
ON
OFF or ON
OFF
Table 9.2.3-1 If electric energy cannot be measured
Check item
"1" "3" LED
Both "1" and "3" LED
are OFF.
Both "1" and "3" LED
ON
are ON.
Only "1" is ON.
Only "3" is ON.
Both "1" and "3" LED
are OFF.
Action
The type of current sensor may be
incorrect. In addition, if the rating of
the used sensor is different from
the primary current, measurement
cannot be taken correctly.
Wiring is not done or may be
wrong. Refer to 7.4 to check the
wiring.
Current sensors on both 1 side and
3 side may be installed in the
reverse direction.
connection.
Voltage wiring may be incorrect.
Check connection of P1, P2, and
P3.
Current sensor on side 1 may be
installed in the reverse order or
current sensors on side 1 and side
3 may be swapped. Check the
connection.
Connection between P1 and P2 or
P1 and P3 may be reserved. Check
the connection.
Current sensor on side 3 may be
installed in the reverse order or
current sensors on side 1 and side
3 may be swapped. Check the
connection.
Connection between P2 and P3 or
P1 and P3 may be reserved. Check
the connection.
Measurement is taken normally.
Check for the
memory address and data format
(double word: 32-bit integer).
9 - 5
QE81WH
Reference
Check the
Section
correct buffer Chapter
7.4
6