YOKOGAWA WT210, User Manual, Page: 123 / 316

7-2
IM 760401-01E
Auto Range Operation
• Range Up
When the measured value of voltage or current (V or A) exceeds 200% of the rated
range or when the peak value (instantaneous voltage or current value that is sampled)
exceeds approximately 300% (approximately 600% if the crest factor is set to 6) of the
rated range, the range is increased the next time the measured value is updated.
• Range down
When the measured value of the voltage or current is less than or equal to 30% of the
rated range and the peak value is less than or equal to approximately 300% (less than
or equal to approximately 600% if the crest factor is set to 6) of the rated range of the
next lower range, the range is decreased the next time the measured value is
updated.
Note
When the range changes, the PLL synchronization will be re-established. Therefore, correct
measurement values might not be obtained which might result in an unstable range. If this is
the case, set the measurement range to a fixed range.
Display Update Rate
In harmonic measurement, you can select the display update rate from 0.25 s, 0.5 s, 1 s,
2 s, and 5 s. For the setup procedure, see section 4.13.
Note
The display update rate of 0.1 s appears as a possible selection when the harmonic
measurement function is ON. However, it cannot be selected. If the display update rate had
been set to 0.1 s when the harmonic measurement function was OFF, the rate is changed to
0.25 s when you turn ON the harmonic measurement function. In this case, the display
update rate remains at 0.25 s even if you turn the harmonic measurement function back OFF.
Holding the Display
When you use the display hold function and change the order or display function while
the harmonic measurement function is ON, you can display the measured harmonic data
at the corresponding time.
Updating the Displayed Data
The display can be updated in the same way as for normal measurement.
Overrange/Error Displays
When the fundamental frequency of the PLL synchronization signal lies outside the
measurement range
Display B will show “FrqEr”.
Note
The measurement range of the fundamental frequency of the harmonic measurement
function is different from the frequency measurement range of normal measurement. Refer to
Chapter 16 for more details.
7.1 Harmonic Measurement Function