YOKOGAWA WT500 User Manual page 315

14.6 Functions
Item
Sample rates, window widths, and upper limits of harmonic analysis
Accuracy, ±(reading error + measurement range error)
The items listed below apply to all of the tables.
• When the crest factor is set to 3.
λ
• When (the power factor) is 1.
• Power figures that exceed 440 Hz are reference values.
• For the external current sensor range, add 100 µV to the current accuracy and (100 µV/external current sensor range rating)
× 100% of range to the power accuracy.
th
• For n order component input, add ({n/(m + 1)}/50)% of (the n
voltage and current, and add ({n/(m + 1)}/25)% of (the n
• Add (n/500)% of reading to the n
the power.
• The accuracy when the crest factor is 6 is the same as the accuracy when the crest factor is 3 after doubling the measurement
range.
• The guaranteed accuracy ranges for frequency, voltage, and current, are the same as the guaranteed ranges for ordinary
measurement.
If the amplitude of the high frequency component is large, influence of approximately 1% may appear in certain orders.
Because the influence depends on the size of the frequency component, if the frequency component is small with respect to
the range rating, the influence is also negligible.
Delta Computation Feature
Item
Voltage (V)
Current (A)
14-14
Specifications
Fundamental frequency Sample rate
10 Hz to 75 Hz f × 1024
75 Hz to 150 Hz f × 512
150 Hz to 300 Hz f × 256
300 Hz to 600 Hz f × 128
600 Hz to 1200 Hz f × 64
• When the line filter is off
Frequency Voltage and current
10 Hz ≤ f < 45 Hz 0.15% of reading + 0.35% of range 0.35% of reading + 0.5% of range
45 Hz ≤ f ≤ 440 Hz 0.15% of reading + 0.35% of range 0.25% of reading + 0.5% of range
440 Hz < f ≤ 1 kHz 0.2% of reading + 0.35% of range
1 kHz < f ≤ 2.5 kHz 0.8% of reading + 0.45% of range
2.5 kHz < f ≤ 5 kHz 3% of reading + 0.45% of range
• When the line filter is on (5.5 kHz)
Frequency Voltage and current
10 Hz ≤ f < 45 Hz 0.4% of reading + 0.35% of range
45 Hz ≤ f ≤ 440 Hz 0.75% of reading + 0.35% of range 1.5% of reading + 0.5% of range
440 Hz < f ≤ 1 kHz 1.2% of reading + 0.35% of range
1 kHz < f ≤ 2.5 kHz 5% of reading + 0.45% of range
th
component of the voltage and current, and add (n/250)% of reading to the n
Delta Computation Setting Symbols and Meanings
Difference
3P3W->3V3A
Delta->Star
Star->Delta
Difference
3P3W->3V3A
Delta->Star
Star->Delta
Window width
1
2
4
8
16
th
order reading) to the n + m
th
order reading) to the n + m
Δ
F1[Udiff]
Δ
F1[Urs]
Δ Δ Δ
F1[Ur], F2[Us], F3[Ut]
F3[Utr] Line voltage computed in a three-
Δ F1[Urs], Δ F2[Ust], Δ
Δ
F2[Idiff]
Δ
F2[It]
Δ F4[In]
Δ F4[In]
Upper limit of harmonic analysis
50
32
16
8
4
Power
0.4% of reading + 0.5% of range
1.4% of reading + 0.6% of range
5% of reading + 0.6% of range
Power
0.85% of reading + 0.5% of range
2.4% of reading + 0.5% of range
10% of reading + 0.5% of range
th th
order and n – m order of the
th th
order and n – m order of the power.
th
Differential voltage between U1 and
U2 determined through computation
Unmeasured line voltage computed in
a three-phase, three-wire system
Phase voltage computed in a three-
phase, three-wire (3V3A) system
phase, four-wire system
Differential current between I1 and I2
determined through computation.
Unmeasured phase current
Neutral line current
Neutral line current
component of
IM 760201-01E