Hioki 3286-20, Инструкция по эксплуатации

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Chapter 2 Measurement Procedure
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U
I
φ
t
2.4.1 1
φ
P Meter, 1
φ
PF Meter and 3
φ
PF Meter
[1
φ
P Meter]
Displays active power P once about every second
(once about every three seconds in SLOW mode).
The meter calculates apparent power S, reactive
power Q, and power factor COS
φ
from active
power P, voltage U, and current I. (See 3.3,
"Operation Expressions.")
[1
φ
PF Meter and 3
φ
PF Meter]
The phase angle is measured at the zero-cross point
of voltage U and current I as shown below. The
meter calculates three-phase active power P, three-
phase apparent power S, three-phase reactive power
Q, and reactive factor SIN
φ
, and power factor COS
φ
from the phase angle
φ
, voltage U, and current I.
(See 3.3, "Operation Expressions.")
For an inverter or thyristor with distorted input
waveforms, or waveforms with noise superimposed,
the meters may not display accurate values or even
be able to measure at all.
Three-phase active power P is calculated on the 3
φ
PF meter under balanced load conditions. Accurate
measurements cannot be conducted under an
unbalanced load.