YOKOGAWA WT500, User Manual

Page: 308 / 360

14-7
IM 760201-01E
Specifications
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14
App
Index
tem Specifications
Effective input range 0 to ±110% of the measurement range for Udc and Idc. *
1 to 110% of the measurement range for Urms and Irms (2 to 220% when the crest factor is set to 6).
*
10 to 110% of the measurement range for Umn and Imn.
*
10 to 110% of the measurement range for Urmn and Irmn.
*
10 to 110% of the measurement range for Uac and Iac. *
However, the synchronization source signal level must meet the frequency measurement input
signal level (see section 14.5 for details).
* 100% for the maximum voltage range.
Maximum display 140% of the rated voltage or current range.
Minimum display As low as 0.5% of the measurement range for Urms, Uac, Irms, and Iac (1.0% when the crest factor
is set to 6). As low as 2% of the measurement range for Umn, Urmn, Imn, and Irmn (4% when the
crest factor is set to 6).
Values lower than these figures are fixed at zero. The integrated current q is dependent on the
current value.
Lower limit of measurement
frequency
Data update interval 100 ms 200 ms 500 ms 1 s 2 s 5 s
Lower limit of
measurement frequency
25 Hz 12.5 Hz 5 Hz 2.5 Hz 1.25 Hz 0.5 Hz
Line filter influence When the cutoff frequency is 500 Hz
45 to 66 Hz: Add 0.2% of reading. Less than 45 Hz: Add 0.5% of reading.
When the cutoff frequency is 5.5 kHz
66 Hz or less: Add 0.2% of reading. 66 to 500 Hz: Add 0.5% of reading.
Conditions for detecting
lead and lag
(D/G, for lead and lag, of
phase angle
f
; sign s
*
when
computing reactive power
Q
Σ
)
Lead and lag are detected correctly when the voltage and current signals are both sine waves, the
lead and lag amplitude is greater than or equal to 50% (greater than or equal to 100% if the crest
factor is set to 6) of the measurement range, the frequency is between 20 Hz and 2 kHz, and the
phase difference is between ±5 and 175°.
* s is the sign for the lead and lag of each element. It is negative when the current leads the
voltage.
Temperature coefficient Add ±0.03% of reading/°C within the range of 5 to 18°C or 28 to 40°C.
One year accuracy Reading error of accuracy at 6 months × 1.5.
Accuracy when the crest
factor is set to 6
Same as the accuracy when the crest factor is 3 after doubling the measurement range.
14.5 Accuracy