Hioki PW3360-20, Инструкция по эксплуатации

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The accuracy of active power calculations can be calculated as follows, taking into
account the phase accuracy:
Example measurement conditions
Wiring: 3-phase/3-wire/2-wattmeter measurement (3P3W2M)
Clamp sensor: Model 9661
Current range: 100 A (power range: 120 kW)
See: "12.6 Range Configuration and Accuracy by Clamp Sensor" (p.187)
Measured values: Active power of 30 kW, power factor lag 0.8
Accuracy
Clamp sensor combined accuracy (Model 9661 sensor, 100 A range): ±0.6% rdg. ±0.15%
f.s.
Instrument phase accuracy: ±0.3°
Model 9661 phase accuracy: ±0.5°
See: "12.3 Detailed Measurement Specifications" (p.165)
"12.6 Range Configuration and Accuracy by Clamp Sensor" (p.187)
Model 9661 Instruction manual “Specifications” phase accuracy
Power factor accuracy based on phase accuracy
Phase accuracy (in combination with clamp sensor)
= Instrument phase accuracy (±0.3°) + Model 9661 phase accuracy (±0.5°) = ±0.8°
Phase difference

=cos
-1
(power factor)=cos
-1
0.8 = 36.87°
Power factor error range based on phase accuracy = cos (36.87° ±0.8°)
= Min. 0.7915 to max. 0.8083
Power factor accuracy based on phase accuracy (minimum) =
=-1.06%, Use the worst value as the power factor accuracy.
Power factor accuracy based on phase accuracy (maximum)=
=+1.04%
 Power factor accuracy based on phase accuracy: ±1.06% rdg.
Active power accuracy
Active power accuracy = Clamp sensor combined accuracy
+ power factor accuracy based on phase accuracy
= ±0.6%rdg. ± 0.15%f.s. ± 1.06%rdg.
= ±1.66%rdg. ± 0.15%f.s.
Accuracy relative to measured values = active power 30kW × ± 1.66%rdg.
+120kW range × 0.15%f.s.
= ±0.678kW
= ±0.678kW/30kW = ± 2.26%rdg.
Appendix3 Method for Calculating Active
Power Accuracy
100%
8 . 0
8 . 0 7915 . 0


100%
8 . 0
8 . 0 8083 . 0

