Feature
Specification |
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Model | ME435 |
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Product component type | Handheld poly-phase power meter |
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Poles description | 3PH4W 3PH3W 1PH2W (L-N); 1PH2W(L-L);1PH3W(L-L-N) |
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Device application | Power analysis Energy meter |
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Input type | External Rogowski coil External CT(333mV only) |
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Display | 3.5 inch TFT screen display |
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Sampling rate | 8k samples per second |
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Harmonic | 52th Max |
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Mechanical characteristics |
Weight | 350g |
Dimension | L*W*D:21.5*10*3.5CM |
Power Meter Characteristics
The power meter measures currents and voltages and reports real-time RMS values for all 3-phases and neutral. In addition, the power meter calculates power factor, realpower, reactive power, and more.
The following sections list the metering characteristics of the power meter.
Real-Time Measuring
The following table lists the metering characteristics of the power meter for the real-time
measurement:
Characteristics | Description |
Current | Per phase, neutral, and average of 3 phases |
Voltage | L-L, L-N, and average of 3 phases |
Frequency | 45...65 Hz |
Active power | Total and per phase (signed) |
Reactive power | Total and per phase (signed) |
Apparent power | Total and per phase(signed) |
Power factor (True) | Total and per phase
0.000 to 1 (signed) |
Current unbalance | Per phase, most unbalanced of 3 phases |
Voltage unbalance | most unbalanced of 3 phases |
Minimum/Maximum Values
When any one-second real-time reading reaches its highest or lowest value, the power meter saves the minimum and maximum values in its nonvolatile memory.
From the power meter display, you can:
• view all min./max. values since the last reset and the reset date and time.
• reset min./max. values.
All running min./max. values are arithmetic minimum and maximum values. For example, the minimum phase A-N voltage is the lowest value in the range from 0 to 999.9GV that has occurred since last reset of the min./max. values.
The power meter provides time stamping for all minimum/maximum values.
The following table lists the minimum and maximum values stored in the power meter:
Characteristics | Description |
Current | Per phase and average |
Voltage | per phase and average |
Active power | Per phase and total |
Reactive power | Per phase and total |
Apparent power | Per phase and total |
Demand Readings
The power meter provides the following demand readings.
Characteristics | Description |
Current | Per phase and average |
Active, reactive, apparent power | Per phase and Total |
Peak Demand Values |
|
Current | Per phase and average |
Active, reactive, apparent power | Per phase and Total |
Demand Calculation Methods
Power demand is the energy accumulated during a specified period divided by the length of the period. Current demand is calculated using arithmetical integration of the current RMS values during a time period, divided by the length of the period. How the power meter performs this calculation depends on the selected method. To be compatible with electric utility billing practices, the power meter provides block interval power/current demand calculations.
For block interval demand calculations, you select a block of time (interval) that the power meter uses for the demand calculation and the mode the meter uses to handle he interval. 2 different modes are possible:
• Fixed block - Select an interval from 1 to 60 minutes (in 1 minute increments). The
power meter calculates and updates the demand at the end of each interval.
• Sliding block - Select an interval from 1 to 60 minutes (in 1 minute increments). For demand intervals less than 15 minutes, the value is updated every 15 seconds. For demand intervals of 15 minutes and greater, the demand value is updated every 60 seconds. The power meter displays the demand value for the last completed interval.
The following figures illustrate the 2 ways to calculate demand power using the block
method. For illustration purposes, the interval is set to 15 minutes.
Peak Demand
In nonvolatile memory, the power meter maintains a maximum operating demand value called peak demand. The peak is the highest value (absolute value) for each of these readings since the last reset.
You can reset peak demand values from the power meter display. You should reset peak demand after changes to basic power meter setup such as power system configuration.
Energy Readings
The power meter calculates and stores Per phase and total energy values for active,reactive, and apparent energy.
You can view energy values from the display. The resolution of the energy value automatically changes from kWh to MWh to GWh (kVAh to MVARh to GWh).
The energy values automatically resets to 0 when it reaches the limit of 999.9GWh,
999.9GVAh, or 999.9GVARh.
The following table lists the energy readings from the power meter:
Characteristics | Description |
Energy values |
|
Active energy | 0 to 999.9GWh
Auto reset to 0 in case of over limit |
Reactive energy | 0 to 999.9GVARh
Auto reset to 0 in case of over limit |
Apparent energy | 0 to 999.9GVAh
Auto reset to 0 in case of over limit |
Power Quality Analysis Values
The power quality analysis values use the following abbreviations:
• Fundamental phase current rms: I1
• Fundamental phase voltage rms: V1
• RMS of up to three harmonics of phase current:
Ix, Iy, Iz, x, y, z = 2, 3,…, N
• RMS of up to three harmonics of phase voltage:
Vx, Vy, Vz, x, y, z = 2, 3,…, N
•Total harmonic distortion of the phase current
• Total harmonic distortion of the phase voltage
• Harmonic distortion of up to three harmonics on the phase
current
• Harmonic distortion of up to three harmonics on the phase
voltage:
THD provides a measure of the total distortion present in a waveform. THD is the ratio of harmonic content to the fundamental and provides a general indication of the quality of a waveform. THD is calculated for both voltage and current.
The following table lists the power quality values of the power meter:
Characteristics | Description |
THD | Per phase current Per phase voltage |