Product description

LMG671 - Power Analysis²

One-shot Results for Narrowband, Full Spectrum and Harmonics

Features:

Features

DualPath

Simultaneous measurement in two bandwidths thanks DualPath - no compromises, no doubt

In Power meters of traditional construction, a signal first passes through an analog processing, the output values ​​are digitized by an A / D converter and then processed. The resulting signal may then either measured over the full range, or treated with anti-aliasing filters, e.g., to serve as the basis for an FFT or other digital filtering. By restriction to an A / D converter, one has to taken certain disadvantages into account. If measured with a filter, in order to avoid aliasing in the FFT, the broadband values ​​are lost. When the filter is disengaged, strictly speaking, the FFT has to be omitted. If the FFT is performed without anti-aliasing filter for measurement over the full bandwidth, the quality of the calculated values ​​is questionable. For example, an aliasing error of 50% would of course be easily detected, a deviation of 0.5% could remain unnoticed. Finally, it can be switched back and forth between measurements with and without filters. The validity of these results is, however, also doubtful, as would be expected of a temporal invariability of the signal, which is hardly ever the case in reality. Moreover, this method is extremely time consuming.

Ultimately, the shown measurement methods are unsatisfactory compromises. For this reason, ZES ZIMMER has radically redesigned the signal conditioning and developed the DualPath architecture. The analog side corresponds to the conventional instruments, the subsequent digital processing, however, was revolutionized. The power analyzers of the LMG600 Series are the first power meters featuring two A / D converters in each of the two independent signal paths for current and voltage channel. A filter for the contact measurement of the broadband signal, and another for the narrowband signal at the output of anti-aliasing filter. By means of parallel processing of the digitized samples, the user has access to both measurements of the same signal without the risk of aliasing. This unique process eliminates all the disadvantages of previous approaches and guarantees accurate results in the shortest time.

Sampling Rate

High sampling rate of up to 1.2 MS/s

Resolution

Calculation of RMS values with a minimum cycle time of 10 ms.

Accuracy

Extremely high measurement accuracy of 0.015 % of the measured value + 0.01 % of the measuring range limit

Dynamic Range

Full dynamic range continuously available from 500 μA to 32 A and 3 mV to 1000 V
Power measurement from standby to full load (max. 32 A) possible without mechanical changes

Bandwidth

Analog frequency range from DC up to 10 MHz

Harmonic analysis of up to 1000th order in the GUI and 2000th order via

interface

Flexibility

The right channel combination for every application

Configuration with 1 to 7 power measuring channels (alternatively 6 measuring channels and Process-Signal-Interface)
Retrofitting of channels available!

Continuity

Complete data collection

In the wake of stricter monitoring of consumption and efficiency of electrical appliances, new standards and procedures (eg SPECpower_ssj2008, IEC 62301) will continuously be created to enable an objective comparison of the different manufacturers. Whether it is workstations, servers or appliances, is irrelevant to the principle: The long-term evaluation of the power consumption has always to take all relevant operating conditions into account. The differences between minimum load - e.g., Idle mode, - and full load can thereby be of considerable magnitude, which requires a very sophisticated means of measurement (see also Application Note No. 102, "Measurement of standby power and energy efficiency."). The measurements must be carried out over several hours and may not show any gaps. By selecting a sufficiently large measurement range, range changes and the inevitably resulting data losses can be avoided. The fundamental precision LMG600 also ensures an accurate measurement at the lower limit of a range.

Exact signal transit time

Exact measurements thanks to minimal runtime differences

The fast switching semiconductors used to improve the efficiency of  modern frequency converters cause extremely steep voltage edges. The resulting capacitive currents affect the bearings and the motor insulation - this can lead to premature failure.
Motor filter (e.g. du / dt filter) attenuate the voltage gradient, but generate themselves power dissipation due to the settling of the filters' frequencies (typically > 100 kHz). The high bandwidth and the small time difference between the current and voltage of the LMG600 enable highly accurate power loss measurements on the filters at these frequencies, and longitudinal measurements with small cos φ. This also applies to power measurements at high bandwidths up to 10 MHz. This requires that the current and voltage channels must be designed for minimum delay differences; in the LMG600 it is less than 3 ns; this corresponds to 50 Hz at an angle error <1 μrad. The instrument is therefore ideally suited for the power loss measurement at small phase angles for transformers, inductors, capacitors and ultrasonic sensors. No options or adjustments are necessary, as the devices will fully meet this measurement task already in the default setting when shipped. For measurements on circuits of highest performance, typically current and voltage transducers are employed. The phase angle of the converter can be corrected via the runtime menu and thus the measurement accuracy can be improved.

Immunity

Reliable even in areas with difficult electromagnetic conditions

A/B/C/S-Channels

For every application the right channel type:

• S-Channel:0.025 % accuracy, up to 10 MHz, DC-optimized, up to 1000 VAC/1500 VDC
• A-Channel: 0.025 % accuracy, up to 10 MHz, up to 1000 VAC
• B-Channel: 0.07 % accuracy, up to 500 kHz, up to 100 0VAC
• C-Channel: 0.04 % accuracy, up to 10 kHz, up to 1000 VAC

Ground Capacitance

Particularly low earth capacitance of < 90 pF avoids interference by leakage currents

 Calibration

12 months guaranteed calibration for low maintenance cost and optimum equipment availability

Free calibration protocol included at first delivery

Warranty

All ZES ZIMMER power meters of the LMG series, the current sensors of PCT series and the voltage sensors of the HST series are carefully tested, adjusted and calibrated prior to shipment and are subject to strict quality controls.
ZES ZIMMER guarantees for a period of 24 months from first delivery that these products are free from defects in material or workmanship.

ZES Warranty Terms

Harmonics

Harmonics and inter-harmonics up to the 1000th order in the GUI and up to the 2000th order via the innterface, in accordance with standards as per EN61000-4-7

Process signals

Process Signal Interface (PSI)

(optional) speed / torque sensor inputs via the menu on all signal types
freely configurable (analog, frequency and RS422, TTL or HTL)

Script Editor

Flexible scripting tool for special applications
Convenient calculation of all derived variables in the power analyzer

Simultaneity

Simultaneous measurement of I, V and P-variables and harmonics
Presentation in tabular or graphical form

Flexible Filter

Signal filter freely adjustable according to frequency, type and characteristics

Plug ’n’ Measure

Convenient commissioning with zero risk of misconfiguration

Although the LMG600 offers an unsurpassed dynamics in both the voltage and current range, there are always applications with exceptional demands on the measurement areas. Whether this is to currents of several hundred amperes and voltages of several kilovolts, ZES ZIMMER has a suitable solution at hand. We provide a wide range of current and voltage sensors that is perfectly matched to the precision power meter LMG600 and expands the measurement range of the instrument to the necessary degree. The sensors of our "Plug'n Measure" series are equipped with a bus system, which allows automatic configuration of LMG600. All important parameters, such as the exact scaling factor, the term compensation quantity, the last calibration date and the sensor type, are automatically read by the power meter and included in the measurements. In addition, the sensors' operating power is supplied by LMG600, so that a separate power supply is not necessary. With "Plug'n Measure" mal-adjustment by the user is avoided and the best possible measurement results are guaranteed. From the user's point of view, no difference between direct and sensor-based measurement is perceptible. Of course, other conventional sensors can also be used with the LMG600.

Synchronization

Synchronize simultaneously on up to seven different frequencies

Flicker

Wechselwirkungen zwischen Netz und Verbrauchern nach EN61000-4-15

Sample Values

Direct access to high-resolution sample values and harmonics via interfaces

Star-Delta

Conversion from phase to phase in the phase voltages and determination of the active power

For a 3-phase 3-wire system only the phase voltages U12, U23, U31 and the phase currents I1, I2, I3 are amenable to measurement. With the help of star-delta conversionline, voltages can be determined in the inaccessible phase voltages, converted into the associated active powers. In analogy, the phase currents can be converted into the "chained" currents. From the values ​​thus calculated, all other variables, e.g. harmonics, are derived. Distortions and asymmetries of power and consumers are considered correctly. The use of an external artificial neutral point is thus superfluous, but such can be connected, if required, at any time, in case the associated disadvantages (e.g. increased power dissipation) are accepted.

Touchscreen

Großflächiges und übersichtliches Farbdisplay, mit 10,1" und 1280x800 Pixeln

Flache Bedienhierarchie, rascher Zugang zu allen wichtigen Funktionen und Einstellungen

DVI-Ausgang für externen Monitor oder Beamer

Remote control

LMG Remote

The LMG Remote PC software allows to easily control the LMG671 remotely from a Windows PC. Since this software mimicks the measuring device itself down to the last detail, the LMG671 can be operated as usual, even from the PC - no rethinking required, no familiarization time.

Memory

Internal storage even of long-term measurements with the shortest cycle time, thanks to high-capacity mass-storage device
Optional additional internal SSD for mass storage of sample data over long time periods

Interfaces

Powerful interfaces

Excellent connectivity with USB3.0, Gigabit-Ethernet, CAN, RS-232 and DVI/HDMI

Custom Menu

The GUI you always wanted…

… in less than 20 minutes

Display only what you really need in a way that helps you most to achieve the task at hand - as easy as 1-2-3:

• Arrange all relevant results on a single screen
• Mix graphical and numerical data to compose meaningful views
• Combine results from different channels and groups
• Enrich measured data with derived values
• Add your individual corporate touch by the use of logos and other graphical elements

Technical Specifications

Technical Data (Summary), valid for 0 ≤ λ ≤ 1

1) 2) 3) 4) only valid in range 10 ... 32 A:

1) additional uncertainty ± 80μA/A2 * Itrms2          2) additional uncertainty ± 80μA/A2 * Itrms2 * Utrms    3) additional uncertainty ± 80μA/A2 * Itrms2        4) additional uncertainty ± 80μA/A2 * Itrms2 * Utrms  

e) Accuracy specification after non-persistent zero adjustment, temperature change after zero adjustment max. ±1°C

The complete technical data can be found in the manual, which is stored on your LMG600 in the valid version.