Model 933A Portable Power Sentinel™

with Digital Signal Analysis

The Arbiter Systems^®, Inc. Model 933A Portable Power Sentinel^TM is the most accurate and most affordable portable power quality meter in the industry. The proprietary EnergyDSA^TM Digital Signal Analysis algorithms allow the user to measure or record harmonics, flicker (per IEC 61000-4-15, P_ST and Instantaneous), K-factor and interruptions. The data logging capabilities allow the user to specify which data to log as well as when to log the data, continuously or when user specified thresholds are exceeded. The high accuracy, portability and data logging capabilities make the Portable Power Sentinel^TM the perfect field analyzer for the power quality engineer.

Portability

Thanks to the high level of integration made possible with EnergyDSA^TM, the Model 933A Portable Power Sentinel^TM combines multiple capabilities into one compact, light weight instrument. Weighing less than 5.8 kg (12.8 lbs), the Portable Power Sentinel^TM is a power quality monitor, a data and event logger, a system monitor, and a revenue meter designed to accompany you wherever you go and operate continuously for a full eight-hour shift.

Capabilities

Primarily designed for the power engineer, the Portable Power Sentinel^TM measures and records harmonics, flicker, K-factor, and interruptions. In addition to these measurements, the Portable Power Sentinel^TM has the ability to measure system time, phase, frequency and phasors. When synchronized using the IRIG-B IEEE-1344 unmodulated input or the GPS input, the Model 933A is capable of accurate revenue metering and synchrophasor analysis per the IEEE-1344. Pre-fault data is buffered for a half second allowing for accurate fault recording and event driven data analysis. The host processor and the DSP each have 128 MB of memory which provides ample space for data storage.

Features

The Model 933A Portable Power Sentinel^TM includes a 320 x 240 graphic LCD display with a CCFL backlight, a 30-key multifunction keypad, adjustable tilt-handle/bail assembly, RS-232 cable, safety ground cable, and power cord.

Communications are made via an RS-232 or USB 1.1 port that supports DNP 3.0, Modbus, PQ-DIF and proprietary protocols.

Both the host and DSP processors have 128 MB of flash memory. The host processor memory stores all data types available including fault data (1/sec and 20/sec) and register data. The DSP memory is primarily for waveform storage with data for all channels continuously stored at approximately 170 samples per cycle, a fixed pre-fault window of 0.5 seconds, and a maximum of about 1000 seconds (17 minutes) of data storage.

The 933A is powered by either NiMH batteries (8 hours typical run time) or an external power supply (85 to 264 Vac or 110 to 370 Vdc).

Options and Accessories

Available options include GPS receiver synchronization for 1 µs timing accuracy allowing for increased revenue accuracy(See this link for more information), optically isolated event inputs, flexible CT inputs, direct current inputs, and programmable KYZ output contacts. Available accessories include a USB cable and a wide selection of test leads.

Model 933A Specifications

Input:

Configuration:: 3Ø: 3-element, 2½-element, 2-element, selectable; 1Ø: 2-element, 1½-element, 1-element, selectable
Voltage:: Range (3Ø/1Ø): 0 to 650 Vrms, selectable (phase-to-phase for 2 and 2½-element; phase-to-neutral for 1 and 3-element); Overrange: 1200 V peak, nominal
Current (Model 933A-01 20 Amp direct input module:: Range (3Ø/1Ø): 0 to 20 Arms, selectable, per element; Overrange: 40 A peak, nominal (maximum continuous input current: 20 Arms per element, all ranges
VA, W, VAR:: Range: Any voltage, current and number of elements within the specified limits
Compensation:: CT and PT: Both magnitude and phase compensation, CT with 12 point nonlinear interpolation; Transformer: Both iron and copper loss
Frequency:: Range: 45 to 65 Hz, for specified accuracy; Harmonics: to 3 kHz
Inputs:: Voltage: Safety banana plugs; Current: 5-way binding posts (20 A direct); Insulation:
400 volts, nominal, to neutral/chassis, surge voltage class III
600 volts, nominal, to neutral/chassis, surge voltage class II

Power Quality:

Harmonics Measurement:: Standard: 2^nd to 50^th (50 or 60 Hz) per IEC 61000-4-7, 100 ms overlapping data window; Measurements: THD, K-factor, rms harmonic current and voltage, rms harmonic current and voltage with K-factor compensation (each harmonic magnitude is multiplied by the square of the harmonic number before summing), individual magnitude and phase; Logged Data: Selectable, may be regularly logged or registered. Event-logged also available when user-specified limits are exceeded.
Interruptions:: Logged Data: Selectable, may be regularly logged or registered. Event-logged also available when user-specified limits are exceeded.
Flicker:: Standard: Per IEC 61000-4-15, P_ST and Instantaneous; Logged Data: Selectable, may be regularly logged or registered. Event-logged also available when user-specified limits are exceeded.
Limit Alarms:: Functions: Upper or lower limits may be set on most measured functions. Limits may also be set on maximum imbalance (ratio of Zero and Negative Sequence Components to Positive Sequence); Output: Via system interface and display

Accuracy:

Note: Accuracy specifications include all sources of uncertainty. Except as noted, specifications apply for the full operating range, including temperature (-10° to +50° C), line voltage, input range including specified overrange, power factor, input frequency, and drifts over a one-year calibration interval. Specifications assume synchronization to GPS and operation in 3-element mode or in a well-balanced system where imbalance does not degrade accuracy.

Watts, Wh: 0.05% of reading, for voltage 7 to 650 Vrms and current 10 mA to 20 Arms and PF > 0.2

Watts, Wh underrange: 0.005% multiplied by (10 mA/Irms) for current < 10mArms, typical

Vrms: 0.05% of reading (typical 0.02% to 1.5 Vrms) (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)

Arms: 0.05% of reading (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)
0.1% (current 10 to 50 mArms)

V²h: 0.1% of reading (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)

A²h: 0.1% of reading (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)
0.2% (current 10 to 50 mArms)

Phase Angle, Ø: 0.01°, phase-to-phase or voltage-to-current (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)
0.2% (current 10 to 50 mArms)

Phase Angle, Ø underrange: 0.05° of reading (current 10 to 50 mArms)

VA, VAh: 0.05% of reading (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)
0.1% (current 10 to 50 mArms)

VAR, VARh: same as W, Wh except replace PF with (1-PF²)^0.5

Power Factor: 0.0002 · sin (Ø) (For voltage 50 to 650 Vrms and current 50 mA to 20 Arms)
0.001 · sin (Ø) (current 10 to 50 mArms)

Harmonics: 0.1% THD or 5% of reading, whichever is greater

Frequency: < 1 ppm (0.0001%) of reading, 50 or 60 Hz nominal, plus timebase error

System Phase: 0.03° plus [timebase error · 360° · frequency] (With GPS Option)

System Time: 1 µs plus timebase error (With GPS Option)

Event Inputs: ±10 µs (typical)

Flash Memory Data Storage:

Host Processor:: Capacity: 128 MB. See Operation Manual for record length and capacity calculations; Data: All functions measured and totalized by Model 933A; each record is stored with a time tag; Storage Rate: Selectable
Event data stored upon occurrence; Lifetime: 100,000 storage cycles minimum; Data Retention: Indefinite; no power or battery is required to retain data
DSP Processor:: Capacity: 128 MB; about 1000 seconds or 17 minutes; Data: Primary waveform; Storage Rate: 10240 samples per second (approximately 170 samples per cycle). Fixed 30 cycles pre-fault data. Event data stored to Host Processor flash memory upon occurrence. User has same triggers as the Host Processor flash and can select the maximum fault duration, post fault recording time, and retrigger on/off.; Lifetime: 100,000 storage cycles minimum; Data Retention: Indefinite; no power or battery is required to retain data

System Control and Monitoring:

System Time, Phase and Frequency:: System Time: Unlimited accumulation with ±1 µs resolution; Frequency: 6 digits, xx.xxxx Hz; System Phase: 0 to 360° with 0.01° resolution
Phasors:: Standard: Per IEEE Standard 1344 or PSCSV; Rate: 20 measurements/second

Interface

Operator:: Display: 320 x 240 graphic LCD display with CCFL Backlight; Keyboard: 30 keys: 5 soft function, 7 dedicated function, 5 cursor control, power on/off and 12 key numeric key pad
Communications:: Serial: RS-232, RJ-11 modular connector; USB: Version 1.1, B-Type receptacle
Protocols:: Proprietary: PowerSentinelCSV (PSCSV); Supported: DNP 3.0, MODBUS, PQ-DIF, MV-90 (pending)

Synchronization

IRIG-B Unmodulated Input:: TTL-Level Shift per IEEE-1344 as output from an Arbiter Systems Model 1084B
Optional Remote GPS Receiver (See this link for more information):: Tracking: GPS-L1 (1575.42 MHz); 12 channel (tracks up to 12 satellites); Acquisition: 2 minutes typical; Accuracy: UTC-USNO ±1 µs (only need 1 satellite with correct position); Out-of-Lock Indication: Via system interface and status display; optional, via contact closure
Timebase Error:: GPS locked: Less than 1 µs, when locked to at least one satellite with correct position; Unlocked: 10 ppm, typical, after being locked for 10 minutes minimum; IRIG-B: Less than 1 µs + accuracy of IRIG-B source

General

Physical:: Size: 205 x 305 x 225 mm (8 x 12 x 8.75 in.)
483 x 483 x 305 mm (16 x 16 x 12 in.), shipping; Weight: 5.8 kg (12.8 lbs), maximum
9.1 kg (20 lbs), shipping
Environmental:: Temperature, operating: -10° to +50° C; Temperature, nonoperating: -40° to +75° C; Humidity: Noncondensing

Power Requirements

Internal Battery:: Type: NiMH; Operation: 8 hours typical; Charging: 4 hours; Stand By Use: 5 VA typical
External Power:: Range: 85 to 264 Vac, 47 to 63 Hz or 120 to 275 Vdc, 25 VA typical when charging battery, 5 VA typical standby use; Input: IEC connector with fuse; surge withstand per ANSI C37-90.1 and IEC801-4 standard

Options

Input Modules:: 933Aopt02 (AS0076500 if ordered separately): 933A-02 CT input current module with banana connectors. Uses standard shrouded banana jacks. Available cables include: CA0029000 - premium shielded cable, shrouded to unshrouded banana jacks and AS0060100 - unshielded cable, shrouded to unshrouded banana jacks.; 933Aopt03 (AS0076700 if ordered separately): 933A-03 CT input current module with audio connectors. Requires use of CA0027100 or CA0027200, available separately.
Programmable KYZ Contacts and Event Inputs (AS0077700):: KYZ Contact Type: Form C (SPDT); KYZ Contact Connections: Pluggable 12-pole 5 mm terminal strip, with four 3-pole mating connectors included; KYZ Contact Rating: 250 Vac/125 Vdc 8A maximum, 2000 VA/150 W maximum; KYZ Contact Isolation: 4000 Vrms for 1 minute to chassis; Event Input Type and Number: Four, optically-isolated 24 to 240 Vdc (may be configured for 5 V logic level); Event Input Connections: Pluggable 8-pole, 5 mm terminal strip, with four 2-pole mating connectors; Event Input Isolation: 4000 Vrms for 1 minute to chassis; Event Input Resolution: 1 µs
Remote GPS Receiver: Provides GPS synchronization for 1 µs timing accuracy. (See this link for more information): Remote GPS Receiver and mounting bracket: AS0077600; Receiver Cable Extender (25 ft.): CA0029800