Model 931A Power System Analyzer

Model 930A Three Phase Power Analyzer

Model 929A Three Phase Power Meter

with Digital Signal Analysis

Arbiter Systems^®, Inc. Models 931A, 930A, and 929A, with state-of-the-art PowerDSA™ Digital Signal Analysis, make more measurements, more accurately, more easily, and at a lower price than ever before. Basic accuracy of 0.05% of reading and 0.05° phase, harmonic analysis, and full three-phase capability are standard on all three models. The 930A and 931A also incorporate full two way serial communication for use in power quality trend monitoring, and for complete power system analysis the 931A also includes a transducer calibration and timer features.

The Arbiter Systems^®, Inc. Model 930A Three Phase Power Analyzer is an economical alternative to the Model 931A Power System Analyzer when the dc voltage measurement, transducer calibration and timer features are not required. The Model 930A has the same ac accuracy as the Model 931A with PowerDSA™ Digital Signal Analysis. The Model 930A with serial communication capability and available application software, in conjunction with a laptop computer, is a valuable tool for use in power quality trend monitoring, as well as being a complete diagnostic tool for use in the substation and industrial power environment.

The Arbiter Systems^®, Inc. Model 929A Three Phase Power Meter is an economical alternative to both the Model 931A Power System Analyzer and the Model 930A Three Phase Power Analyzer when serial communication, dc voltage measurement, transducer calibration and timer features are not required. The Model 929A has the same ac accuracy as the Model 931A with PowerDSA™ Digital Signal Analysis, and is a complete diagnostic tool for use in the substation and industrial power environment.

Portability

Thanks to the high level of integration made possible with PowerDSA™, our instruments are lighter, smaller, and run longer on a charge than any others in this class. Smaller than a lunchbox and weighing only 5.8 kg (12.8 pounds), you can take any of our PowerDSA™ instruments with you wherever you go, operate it continuously for a full 8-hour shift from its internal sealed lead-acid battery, and then recharge it completely in eight hours.

Safety

Built in a rugged, non-conductive high-impact polyethylene case, and with all inputs isolated from instrument common by transformers, optical isolators or high-value series resistors, these instruments were designed with safety in mind. A front-panel ground terminal provides a sink for leakage currents.

SAFETY NOTICE: Grounding the Model 931A Power System Analyzer:

Operating the 931A Power System Analyzer without connecting to a safety ground is an unsafe practice. The chassis is galvanically isolated for the Voltage and current inputs. However, due to capacitive coupling the chassis will float to the average value of the voltage inputs when not properly grounded. This means if the A, B, and C Voltage inputs have a potential of 750 Volts with respect to the neutral input the chassis could float to over 400 Volts rms. The available current is very minimal so this potential is no where near lethal. A well-grounded person may feel a tingle when touching metal chassis parts.
931A's have two safety ground connections, a binding post and the third wire of the IEC power inlet. Both are directly connected to the chassis. They are isolated from all inputs, the RS232 connector and the internal signal ground. One of these safety grounds should be connected to a low impedance earth ground. This is especially true when measuring high Voltage.
Connecting the safety ground after the chassis has floated to a high potential will result in a large EMI spike. The LCD display is sensitive to this EMI spike and may go blank. If this occurs, press the power key to turn off the instrument. Connect the safety ground and turn the instrument back on.

Convenience

The outstanding features do not end with light weight, measurement flexibility, or unprecedented accuracy. Many other user conveniences have been added to ease your workload.

Bright, easy to read CCFL-backlit graphic display, with big, easy-to-read numeric results
STORE, RECALL, and LAST SETUP capability
Built-in HELP text
Opto-isolated serial interface (Models 931A & 930A)
LOG DATA to internal memory (or an RS-232 printer with Models 931A and 930A), time and date tagged from the internal real-time clock.

Options and Accessories

Available options include an additional 16 megabytes of internal data memory to provide storage for data logging (not available for the Model 929A), 931A Application Software, 930A Application Software, an adjustable tilt handle/bail assembly for the transit case.

Available accessories include a 400 Amp 20:1 precision CT, mounting brackets to provide for mounting of CT's inside the cover of the transit case, a wide selection of test leads, and an RS-232 cable.

All of this, and more, is ready to help you do your job better and in less time. Put an Arbiter Systems^® Model 931A, Model 930A, or Model 929A, all with PowerDSA™ Digital Signal Analysis to work for you soon!

Basic Measurements

The 931A, 930A, and 929A measure all of the basic quantities: true-rms voltage and current, frequency and phase angle. PowerDSA™ analysis measures these quantities more accurately than ever before. Accuracy is 0.05% for voltage and current and 0.05° for phase. The proprietary PowerDSA™ narrow-band mode even measures the fundamental signal alone, rejecting the effects of harmonics and noise. In wide-band mode, the effects of all harmonics and noise are included. Phase angle is always true, fundamental phase, and frequency is accurate even with large harmonics causing multiple zero crossings. Accuracy is never degraded, even with real-world signals.

Power Quantities

The PowerDSA™ instruments measure power quantities, too, with accuracy unprecedented for a lightweight, portable instrument. Measurements are made in accordance with IEEE standards, including the effects of harmonics and reactive power. Watts (W), watthours (Wh), volt-amperes (VA), volt-ampere hours (VAh), volt-amperes reactive (VAR), volt-amperes reactive hours (VARh), and power factor (PF): PowerDSA™ analysis measures them all, with 0.11% basic accuracy.

Harmonics

Measure harmonics and view the results graphically; as summary numbers, such as total harmonic distortion (THD), even harmonic distortion (EHD), odd harmonic distortion (OHD) or K-factor; or as individual harmonic amplitude and phase. The bandwidth extends to over 3 kHz for accurate measurement to the 50^th harmonic on 50 or 60 Hz systems, now you can know for sure what is really happening on your system.

Waveform Display

You can view the signal waveforms for both channels on the high contrast 240x64 graphic display. Both channels are normalized to Channel 1 fundamental phase, so you can see, for example, the relationship between current waveform distortions and voltage phase.

Timer

(Model 931A)
The Model 931A's timer/counter (not available on the Model 930A/929A) measures relay operating times or elapsed test times, or counts input rates and events. View times in seconds or in terms of power-line cycles. Both inputs are independently opto-isolated for safety and flexibility.

Three-Phase Measurement

The 931A, 930A, and 929A include a full three-phase input section, for automated three-phase measurement sequences. PowerDSA™ analysis measures two signals at a time, and the results are combined into four complete three-phase displays. You can select from the following three-phase display modes: Basic three-phase display View voltage, current, phase, frequency and power quantities on one convenient display. Vector display View voltages, currents and phase angles with their vector representation. Voltage/Current Sequence display View voltage, current and phase along with positive, negative and zero sequence values. Energy display View voltage, current, phase, frequency and energy quantities on one convenient display. As a power trend monitor and recording system, these PowerDSA™ instruments can verify phase relation, phase rotation, power direction, load balance and positive, negative, and zero sequence of voltage and/or current as well as calibrating and verifying in-service performance of Disturbance, Fault and Transient Recorders.

Transducer Calibration

(Model 931A)
The outstanding accuracy of the Model 931A with PowerDSA™ is ideal for transducer calibration. The Model 931A includes the necessary dc voltage and current measurements to accurately measure transducer outputs, using a separate, opto-isolated input section. With only an external source or load box, or when making in-service measurements, the Model 931A provides complete field transducer calibration.

CT/PT Ratios

Correction factors for external CTs and/or PTs, can be entered to display the measured results in input-side units. You can even measure ratios using the instrument's CH1/CH2 function. This example shows a nominal 200:1 (or 1000:5) current ratio; if Channel 1 is a CT burden voltage and Channel 2 CT secondary current, the result is the loop resistance in ohms.

Extended Measurement Ranges

For greater accuracy, the Model 09311A Auxiliary CT allows measurement of signals up to 400 amps with total basic accuracy of 0.1%. This CT mounts directly to the Model 931A, 930A, or 929A current input connectors and may be used for one two or three of the current inputs, depending on your needs.

Model 931A Specifications

Input:

Basic Inputs & Measurements:: The Arbiter Systems^® Model 931A Power System Analyzer has two main measurement channels, Channel 1 and Channel 2. Any voltage or current input signal may be selected for either channel. For basic measurements (voltage, current, frequency, phase angle) any combination of inputs may be used. For power and energy measurements (active power, apparent power, reactive power and power factor), one voltage and one current must be selected. For three-phase measurements, the input configuration is selected automatically, based on the measurement type (for example, 3-phase 4-wire 3-element).
Voltage:: Input Range 1.5 to 750 Vrms (underrange to 200 mV) [2 to 1000 Vdc (Model 931A Only)]; Inputs Four; A, B, C, N
Phase-to-Phase
Phase-to-Neutral
Phase-to-Synthesized Neutral (A+B+C / 3); Impedance 1 megohm; Leakage < 3.5 mA per IEC348 and UL1244
Current:: Input Range 0.04 to 20 Arms (underrange to < 1 mA); Inputs Three; A, B, C, plus synthesized neutral; Burden 0.01 ohm maximum; Isolation Transformer, 1000 Vrms; Neutral Synthesized, -(A+B+C)
Timer: (Model 931A Only): Inputs Two; 4 to 300 Vdc; 20 to 300 Vrms; or dry contact/thyristor output; Isolation Optical, 300 Vrms, each channel
Transducer: (Model 931A Only): Range 0 to 1, 0 to 100 mAdc and 0 to 10 Vdc; Protection Overvoltage to 120 V, both inputs; Isolation Optical, 300 Vrms

Measurements:

Voltage and Current:: Method Wideband: True rms, 3 kHz Bandwidth
Narrowband: Fundamental magnitude; Accuracy 0.05% of reading; Underrange < 1% of reading, typical at 0.3 mArms; DC voltage (Model 931A only) 0.1% of reading + 25 mVdc, typical
Phase Angle:: Input Channel 1 to Channel 2; Range 0 to 360° or ±180°; Accuracy 0.05°; Underrange < 1°, typical at 0.3 mArms
Frequency:: Input Channel 1; Range 20 to 500 Hz (underrange to 5 Hz); Accuracy 0.005% of reading
Harmonics:: Input Channel 1 or Channel 2; Range 2nd to 50th Harmonic (50 or 60 Hz fundamental); Accuracy 5% of THD reading + 0.01%; Display THD; K-factor; Amplitude bar graph; and individual harmonic magnitude and phase (simultaneous)
Waveform:: Display Channel 1 and/or Channel 2
Power / Energy Quantities:: Range 0 to 99999 MVA or MVAh
±99999 MVAR or MVARh
±99999 MW or MWh
±1.0000 PF, lead or lag; Accuracy 0.11% of VA, for VA, VAR, and W, 0.001 PF
Transducer (Model 931A Only):: Accuracy 0.05% of reading + 0.01% range
Timer (Model 931A Only):: Range 0.0001 to 9999.9 seconds, or 0.01 to 999999 cycles; Accuracy 0.005% of reading + 1 digit; AC Trigger Add 1 ms maximum, 0.15 ms at 120 Vrms

Interface:

Operator Interface:: Display 240x64 graphic LCD with cold-cathode fluorescent lamp (CCFL) backlight; Keyboard 21 function keys plus On/Off; Memory EEPROM (calibration data)
Battery backup RAM (setup and stored results)
Real-time clock; Data Instrument calibration data
User setups (up to six)
Logged data (15 to 200); time-tagged
System Interface (Model 931A and 930A Only):: RS-232 1200 to 115,200 baud; 7 or 8 data bits; 1 or 2 stop bits; even/odd/no parity; Isolation Optical, 300 Vrms

Power Requirements:

Internal Battery:: Type Sealed lead-acid; Operation 8 hours typical; Charge 8 hours typical; fast + float charge
External Power:: Range 85 to 264 Vac, 47 to 440 Hz, 15 VA maximum
110 to 250 Vdc, 15 W maximum; Safety Designed to meet UL, CSA, VDE

General:

Physical:: Size 205 x 305 x 225 mm (8 x 12 x 8.75 in.)
483 x 483 x 483 mm (16 x 16 x 16 in.), shipping; Weight: 5.8 kg (12.8 lbs), net
8.2 kg (18 lbs), shipping
Environmental:: Operating Temperature -10° to +50° C; Nonoperating Temperature -40° to +75° C; Humidity Noncondensing

Options:

Order Number:	Description
930Aopt01:	16 MB memory
931Aopt01:	16 MB memory

Accessories:

Included:

Order Number:	Description
812H:	Safety Ground Lead
CA0019806:	RS-232 Null Modem Cable, DB9F-DB9F, 2 m (6 ft) length
P01R-P10R:	Power Cord (More information)
PD0017400:	931A Operation Manual
PD0024400:	929A/930A Operation Manual

Available:

Order Number:	Description
09311A:	400 Amp 20:1 Precision CT, 0.1% Accuracy
811AT:	Three-Phase Universal Test Plug Current Lead Set
813AT:	Three-Phase Safety Voltage Lead Set
816AT:	Three-Phase Spade-Lug Current Lead Set
AP0009800:	100:1 Clamp-on CT, 100 A
AS0035901:	Adjustable Tilt Handle/Bail Assembly
AS0036000:	400 Amp CT Bracket (each)
AS0060000:	PowerCSV
AS0060100:	Single-Phase Clamp-On CT Test Lead

Right Angle Power Cord styles:

No.	Country	Specification	Rating
P01R	Cont Europe	CEE7/7	220V
P02R	Aust/NZ/PRC	AS 3112-1981	240V
P03R	U.K.	BS 1363	240V
P04R	Denmark	Afsnit 107-2-01	240V
P05R	India	BS 546	220V
P06R	Israel	SI 32	220V
P07R	Italy	CEI 23-16-VII 1971	220V
P08R	Switzerland	SEV 1011.1959	220V
P09R	N America and ROC	NEMA 5-15P CSA C22.2 #42	120V
P10R	Japan	JIS8303	120V

POWERCSV SOFTWARE

Enhance the performance of your Model 931A Power System Analyzer or Model 930A Three Phase Power Analyzer with the new PowerCSV software (order number AS0060000). The PowerCSV software allows a computer, via the serial port, to import and view data from the extended memory of the Models 931A and 930A. The PowerCSV also has the ability to export a comma-delineated file of the data for easy viewing in any spreadsheet program.

Requires that the Optional 16 MB of Internal Data Memory is installed.

The PowerCSV software is available on our web site: www.arbiter.com.

16 MB Internal Data Memory

Add another useful feature to the Models 931A and 930A with the 16 MB Internal Data Memory option (order number 931Aopt01 and 930Aopt01). The 16 megabytes of storage space can turn the Models 931A and 930A into stand alone Trend Monitors. The characteristic flexibility of the Model 931A Power System Analyzer and the Model 930A Three Phase Power Analyzer is incorporated into the 16 MB Internal Data Memory options allowing for custom and user friendly configuration.

When equipped with the Extended Memory option, the 931A and 930A can be configured to log data at a set interval, on a valid timer trigger (Model 931A only), when the front panel log key is pressed or via the RS-232 LOG command. Two different types of data sets are available for storage, normal and custom. Normal data sets include four data modes:

Standard data, Narrow-Band and Wide-Band parameters for Channels 1 and 2 along with Timer (Model 931A only) and Transducer (Model 931A only) parameters (153 bytes)
Harmonic data, adds the harmonic information from Channels 1 and 2 to the standard data record (945 bytes)
Waveform data, includes standard data, harmonic data, plus the waveform records for Channel 1 and 2 (1,425 bytes)
Three-phase data, the three-phase measurement data for the selected three-phase display mode (366 bytes)

The Custom data set allows the user to select any combination of the thirty available individual parameters to log. Record size is dependent on the selected parameters.

The logged data can be reviewed from the front panel of the Models 931A and 930A or downloaded via the RS-232 port to a computer. Exported data can be easily incorporated into a spreadsheet or word processor for inclusion into reports. The PowerCSV Application Software is a useful tool to transfer the data stored in the internal memory to a computer.