YOKOGAWA WT210, Руководство пользователя, Страница: 40 / 316

1-3
IM 760401-01E
Functional Overview and Digital Display
1
1.2 Functions
Input Functions
Voltage and Current Input Sections
The WT210/WT230 is a digital power meter that can measure the RMS value of
voltage or current, or active power by applying voltage and current signals to the
voltage and current input sections, respectively. From the measured values of
voltage, current, and active power, power elements such as apparent power, reactive
power, power factor, and phase angle can be determined.
Frequency Measuring Range
Measurement of DC voltage, current and power as well as AC voltage, current, and
power in the frequency range of 0.5 Hz to 100 kHz.
Input Filter
The following two types of input filters are provided. The filters eliminates noise such
as inverter waveforms and distorted waveforms and allow stable measured values to
be obtained.
• Line Filter
This filter is inserted only into the measurement circuit. It eliminates noise
components of the input signal. The cutoff frequency is 500 Hz.
• Frequency Filter
This filter is inserted only into the frequency measurement circuit. The cutoff
frequency is 500 Hz. Since the WT210/230 is making measurements in sync with
the input signal, the frequency of the input signal must be measured correctly.
Wiring System
The input units for voltage or current are located on the rear panel of this instrument.
These units are called input elements. The number of input elements depends on the
model, and the possible wiring systems are shown in the table below. The wiring
system indicates the circuit configuration for measuring voltage, current, and power.
The name of the system varies depending on the phase and number of electrical
wires making up the circuit.
Model Number of Elements Wiring Systems Supported
760401 1 Single-phase, two-wire (1P2W)
760502 2 Single-phase, two-wire (1P2W); single-phase, three-wire
(1P3W); three-phase, three-wire (3P3W)
760503 3 Single-phase, two-wire (1P2W); single-phase, three-wire
(1P3W); three-phase, three-wire (3P3W); three-phase, four-
wire (3P4W); three-voltage, three-current (3V3A)
Display Functions
Measured/computed values are displayed on three red high-intensity 7-segment LED
displays. You can view three values simultaneously.
You can select the display update rate (0.1 s to 5 s) and the number of displayed digits
(4 or 5) for voltage, current, and active power values.
Peak Measurement Function
This function measures the peak values of the voltage and current. This value is used to
compute the crest factor.
MAX Hold Function
This function holds the maximum values of the voltage, current, active power, apparent
power, reactive power, voltage peak, and current peak. It holds the maximum value that
exists while the MAX hold function is enabled.