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ERT-5 Large-Scale Ground Grid Earth Resistance Tester

ERT-5 Large-Scale Ground Grid Earth Resistance Tester

ERT-5 Digital Intelligent Large-Scale Ground Grid Earth Resistance Tester with 5A High-Current Output, Dual-Frequency Anti-Interference, Step & Touch Voltage Measurement, for Substation & Power Plant Grounding System Evaluation.

Description
Specifications
Applications
Advantages
FAQ
Recommended Products

Description

ERT-5 is a professional flagship large-scale ground grid earth resistance tester designed for comprehensive evaluation of grounding systems in 110kV~1000kV substations, power plants, large industrial plants and wind farms. It strictly complies with DL/T 475-2017, GB/T 17949.1-2000 and IEC 61557-5:2019 standards, adopting advanced dual-frequency synchronous measurement technology that effectively suppresses 50Hz/60Hz power frequency interference, ensuring accurate measurement results even in strong electromagnetic environments of 500kV and above substations.

The instrument features 5A high-current output and 400V maximum open-circuit voltage, enabling accurate measurement of large-area ground grids with high soil resistivity. It supports comprehensive test functions including ground resistance, ground impedance, soil resistivity (Wenner four-pole method), step voltage, touch voltage and ground potential rise. The 7-inch high-definition color touch screen provides intuitive operation and real-time display of test curves and data.

Specifications

Parameter	Specification
Compliance Standards	DL/T 475-2017, GB/T 17949.1-2000, IEC 61557-5:2019, IEEE Std 80-2013
Test Principle	Dual-frequency synchronous current-voltage method
Test Frequencies	45Hz/55Hz automatic dual-frequency conversion
Output Current	0~5A DC continuously adjustable
Maximum Open-Circuit Voltage	400V DC
Ground Resistance Range	0.001Ω ~ 5000Ω
Resistance Resolution	0.001Ω
Resistance Accuracy	±(2% of reading + 0.005Ω)
Soil Resistivity Range	0.01Ω·m ~ 9999kΩ·m
Voltage Measurement Range	0 ~ 200V AC/DC
Voltage Accuracy	±(1% of reading + 0.01V)
Test Modes	Three-pole method, four-pole method, potential drop method, current-voltage method
Test Functions	Ground resistance, ground impedance, soil resistivity, step voltage, touch voltage, ground potential rise
Display	7-inch 800×480 color capacitive touch screen
Language Support	Chinese / English bilingual
Data Storage	2000 groups test data + curves
Communication Interface	USB 2.0 (data export)
Report Generation	One-click Word format report
Power Supply	AC 220V±15%, 50Hz±2Hz
Power Consumption	≤500W (peak)
Operating Temperature	-10℃ ~ +50℃
Humidity	≤85% RH (non-condensing)
Dimensions (L×W×H)	440×350×210mm
Weight	~18kg (including all components)
Enclosure	Rugged aluminum alloy, IP54

Applications

Core Test Objects

Substation ground grids: 110kV, 220kV, 500kV, 1000kV substation grounding systems
Power plant ground grids: Thermal power plants, hydroelectric power plants, nuclear power plants, wind farms, photovoltaic power plants
Industrial ground grids: Large industrial plants, petrochemical plants, steel mills, data centers
Other grounding systems: Lightning protection grounding systems, communication base station grounding systems

Typical Usage Scenarios

Power companies: Substation preventive maintenance, new construction acceptance, grounding system transformation
Power plants: Generator grounding system test, auxiliary equipment grounding inspection
Design institutes: Grounding system design verification and acceptance
Third-party testing institutions: Grounding system certification testing, safety assessment
Industrial enterprises: Internal grounding system regular inspection and maintenance

Advantages

Compliance with Latest International Standards

Fully meets DL/T 475-2017, IEC 61557-5:2019, IEEE Std 80-2013 → test results are globally recognized

Industry-Leading Dual-Frequency Anti-Interference

45Hz/55Hz synchronous measurement technology effectively eliminates power frequency interference → accurate measurement even in strong electromagnetic environments of 500kV substations

5A High-Current Output

5A high-current and 400V open-circuit voltage ensure stable measurement of large-area ground grids and high-resistance soil → solves the problem of inaccurate measurement of traditional low-current testers

Comprehensive Test Functions

Supports all grounding system parameters including ground resistance, soil resistivity, step voltage and touch voltage → one instrument completes all grounding system tests

Intelligent Data Processing & Report Generation

Real-time curve display, automatic result judgment and one-click standardized report generation → simplifies data analysis and report writing, reduces operator workload

FAQ

Q: What is the advantage of dual-frequency technology compared to traditional power frequency method?

A: Traditional power frequency method is susceptible to 50Hz/60Hz power frequency interference from nearby power lines and equipment, leading to inaccurate measurement results. ERT-5 adopts 45Hz/55Hz dual-frequency synchronous measurement technology, which can automatically eliminate power frequency interference through digital signal processing. It ensures accurate measurement even with 20V interference voltage, making it ideal for testing in strong electromagnetic environments of substations and power plants.

Q: Why does large ground grid testing require high-current output?

A: Large-area ground grids have low grounding resistance (typically 0.5Ω~4Ω) and high distributed capacitance. Low-current testers cannot provide enough current to overcome the influence of distributed capacitance and contact resistance, leading to unstable and inaccurate measurement results. ERT-5's 5A high-current output ensures sufficient current injection into the ground grid, providing stable and reliable measurement results that truly reflect the actual grounding performance.

Q: What is the significance of step voltage and touch voltage testing?

A: Step voltage and touch voltage are key safety indicators of grounding systems. When a ground fault occurs, excessive step voltage or touch voltage may cause electric shock hazards to personnel. According to DL/T 475-2017 and IEEE Std 80-2013 standards, step voltage should not exceed 70V and touch voltage should not exceed 50V for general personnel. ERT-5 can accurately measure these parameters and automatically calculate safety margins, ensuring the safety of grounding systems.

Q: How to calibrate the instrument?

A: ERT-5 can be calibrated using standard resistors and standard voltage sources with accuracy not lower than 0.2 class. The calibration procedure is simple and fast: