Mitsubishi Electric Melsec Q Series User Manual page 118

9 Troubleshooting
9.2.4 If the electric current and voltage that are measured using this module do not match with the ones
measured with other gauge
Table 9.2.4-1 If current and voltage that are measured using this module do not match with the ones
Check item
Are phase wire method, primary
current, and primary voltage correct?
Does the compared gauge measure
the effective value correctly?
Is the secondary of CT
short-circuited?
Are you using other current sensor
than recommended ones?
measured with other gauge
Check the value in the buffer memory for checking
the phase wire method, primary current and
primary voltage. When the value in the buffer
memory is changed, you need to turn the request
for operating condition setting into ON. Otherwise,
it will not be applied to the measurement.
This module stores the effective value into the
buffer memory. If the compared device uses the
average value instead of the effective value, the
resulted value may largely differ when there is
current distortion in the measurement circuit.
Make sure that the secondary of CT is not
short-circuited. If it is connected to Mitsubishi's
current transformer CW-5S(L), check that the
secondary switch is not short-circuited.
Only the dedicated current sensors can be
connected to this module. Check that other
company's sensor is not being used.
9 - 6
Action
QE81WH
Reference
Section
7.5.3
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