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SMG2000B Digital Dual-Clamp Phase Volt-Ammeter Technical Analysis and Engineering Application Guide
I. Product Positioning and Core Functions
The SMG2000B Digital Dual-Clamp Phase Volt-Ammeter is a high-precision handheld instrument designed for on-site power system testing. Its core functions include:
a.Multi-parameter measurement: AC voltage (20 V–500 V), current (200 mA–10 A), phase angle (0°–360°).
b.Phase relationship analysis: Supports U-U, U-I, and I-I phase difference measurements with ±3° accuracy.
c.Intelligent diagnostics: Inductive/capacitive load discrimination, three-phase system phase sequence detection, transformer wiring group verification.
d.Non-invasive measurement: Dual-clamp current transformer design eliminates the need to disconnect circuits.
II. Key Technological Innovations
1.Dual-Channel Isolated Measurement System
a.Fully electrically isolated input channels (withstands 1000 V for 1 minute).
b.Independent 40 kΩ high-impedance design (phase measurement mode).
c.Dual-clamp synchronous sampling technology (3 updates per second).
2.Error Control Technology
a.Composite error model: ±(1.0% RD + 2) for voltage/current measurements.
b.Temperature compensation algorithm: Ensures error ≤ ±2× baseline within 0–40°C.
c.Waveform adaptability: Supports non-ideal sine waves with distortion rate β ≤ 0.05.
III. Typical Engineering Applications
1.Power Quality Analysis
Case: 10 kV distribution line power factor anomaly investigation
Connect U1 to Phase A voltage, clamp I2 onto Phase C current.
Switch to U1I2 mode; measure phase angle (result: 248°).
Calculate power factor (0.41) using voltage/current magnitudes.
Diagnose excessive capacitive load compensation.
2.Relay Protection System Verification
Bus differential protection test:
Synchronously measure phase relationships across CT secondary circuits.
Verify phase differences ≤ ±5° between branch currents.
Detect #3 feeder phase deviation (12°), confirming CT polarity reversal.
3.Three-Phase System Phase Sequence Identification
Four-wire system test data:
Connection | Positive Sequence Angle | Negative Sequence Angle |
A-U1, B-U2 | 120° ±5° | 240° ±5 |
A-U1, C-U | 300° ±5° | 60° ±5° |
IV. Measurement Performance Analysis
1.Voltage Measurement Characteristics
Range | Resolution | Input Impedance | Error Band |
20 V | 0.01 V | 2 MΩ | ±(0.2 V + 2 digits) |
200 V | 0.1 | 2 MΩ | ±(2 V + 2 digits |
500 V | 1 V | 2 MΩ | ±(5 V + 2 digits) |
Optimization: Use the 20 V range for <200 V measurements to improve resolution by 10×.
2.Phase Measurement Constraints
| Measurement Type | Amplitude Range | Frequency Tolerance | Waveform Distortion |
U-U | 30–500 V | ±0.5 Hz | β ≤0.05 |
I-I | 10 mA–10 A | ±0.5 Hz | β ≤0.05 |
U-I | 10 V–500 V/10 mA–10 A | ±0.5 Hz | β ≤0.05 |
V. Field Operation Guidelines
1.Phase Measurement Precautions
a.Polarity marking rules:
Voltage terminals: "*" mark on U1/U2 ports.
Current clamps: Red "*" faces the load side.
b.Common errors:
Reversed I2 clamp installation causes phase display error (360°–θ).
Misinterpreting capacitive load phase angles (270°–360°).
2.Environmental Adaptability
a.Activate anti-humidity mode (10-minute preheating) when humidity >80% RH.
b.EMI protection:
Stay ≥1 m away from conductors carrying ≥100 A.
Avoid co-installation with variable-frequency drives.
VI. Maintenance and Calibration
1.Self-test:
a.Zero-check all ranges under no-load (tolerance: ±2 digits).
b.Validate with a 50 Hz/100 V–0.5 A standard source (phase error ≤±1°).
2.Battery management:
a.Runtime >200 hours (9 V alkaline battery).
b.Low-voltage alert threshold: 7.2 V ±0.2 V.
VII. Future Technical Development
Proposed upgrades for smart grid compatibility:
1.Bluetooth 4.0 data transmission.
2.Harmonic analysis module (IEC 61000-4-7 compliant).
3.Auto-ranging optimization algorithms.
4.Enhanced IP54 protection rating.
This guide integrates SMG2000B field data and engineering cases to deliver a comprehensive solution for power technicians. Regular firmware upgrade training is recommended to maximize device performance.
GDZX is a manufacturer of power testing equipment, offering a wide range of models and professional technical support.
Contact: +86-27-6552607 / +86-17396104357. Website：http://en.gdzxdl.com/
