Advanced Smart Multi-Function Earth Resistance Tester - High-Resolution Fast-Detection User-Friendly Real-Time Protection

• Customization: Available
• After-sales Service: Provided
• Warranty: One-Year
• Model NO.: NR3002E
• Accuracy Grade: 1
• Load Way: Electronic Load
• Display: Digital
• Control: Computer Control
• Weight: 7kg
• Power Source: DC 3.7 Lithium Battery
• Function1: Ground Resistance Test, Loop Resistance Test
• Function2: AC Current Test, AC Voltage Test
• Accuracy Guaranteed Temperature and Humi: 23℃±5℃, Below 75%Rh
• Current Resolution: 0.001mA
• Voltage Resolution: 0.01V
• Power Consumption: 750mA Max
• Working Temperature and Humidity: -10℃~40℃,80%Rh or Below
• Storage Temperature and Humidity: -20℃~60℃,70%Rh or Below
• Pressure Resistance: AC 3700V/RMS(Between Circuit and Outside)
• Transport Package: Wooden Box with Foam Inside
• Specification: 277mm×227mm×153mm
• Trademark: Refine On
• Origin: China
• HS Code: 9030332000
• Production Capacity: 100 Set Per Week
• Package Size: 37.00cm * 28.00cm * 26.00cm
• Package Gross Weight: 10.000kg

Product Description

Product Description

PRODUCT FUNCTION

NR3002E Multi-function Earth Resistance Tester Manual 

Introduction

The multi-function ground resistance tester, also known as the ground resistance tester, integrates multiple measurement methods into one advanced instrument. In addition to the traditional function of measuring ground resistance by driving auxiliary ground electrodes, it also features the unique capability of measuring without auxiliary ground electrodes.Through microprocessor control, it precisely measures ground resistance using four-wire, three-wire, simplified two-wire, selective, and dual-clamp methods. The large-diameter current clamp design employs dual-clamp measurement technology, enabling online measurement without the need for auxiliary ground electrodes or isolating the grounding body from equipment. It is widely used in telecommunications, power systems, weather stations, equipment rooms, oil fields, power distribution lines, transmission towers, gas stations, factory grounding networks, lightning rods, etc. The instrument is characterized by accurate, fast, simple, stable, and reliable testing.

Technical Parameters

1.Measurement Ranges, Accuracy, and Resolution

Measurement Function	Range	Accuracy	Resolution
two/three/four-WireGround Resistance(Re)	0.000Ω~19.999Ω	±1.5%rdg±70dgt	0.001Ω
	20.00Ω~199.99Ω		0.01Ω
	200.0Ω~1999.0Ω		0.1Ω
	2.000kΩ~19.999kΩ		1Ω
	20.00kΩ~200.00kΩ		10Ω
DC Resistance(R-)	0.000Ω~19.999Ω	±1.5%rdg±70dgt	0.001Ω
	20.00Ω~199.99Ω		0.01Ω
	200.0Ω~1999.9Ω		0.1Ω
	2.000kΩ~19.999kΩ		1Ω
	20.00kΩ~200.00kΩ		10Ω
Selective Method Ground	0.00Ω~20.00Ω	±2%rdg±30dgt	0.01Ω
	20.0Ω~200.0Ω		0.1Ω
	0.200kΩ~3.000kΩ		1Ω
Dual-Clamp Ground Resistance(Re)	0.00Ω~9.99Ω	±10%rdg±10dgt	0.01Ω
	10.0Ω~99.9Ω		0.1Ω
	100Ω~200Ω	±15%rdg±10dgt	1Ω
Soil Resistivity	0.00Ωm~99.99Ωm	ρ=2πaR (2)	0.01Ωm
(ρ)	100.0Ωm~999.9Ωm		0.1Ωm
	1000Ωm~9999Ωm		1Ωm
	10.00kΩm~99.99kΩm		10Ωm
	100.0kΩm~999.9kΩm		100Ωm
	1000kΩm~9999kΩm		1kΩm
AC Voltage	0.000~9.999V	±1.5%rdg±50dgt	0.001V
	10.00~50.00V		0.01V
AC Current	0.00mA~9.99mA	±2%rdg±50dgt	0.01mA
	10.00mA~99.99mA		0.01mA
	100.0mA~999.9mA		0.1mA
	1.000A~9.999A		1mA
	10.00A~99.99A		10mA
	100.0A~999.9A		0.1A
DC Voltage	0.000~9.999V	±1.5%rdg±50dgt	0.001V
	10.00~50.00V		0.01V
Temperature Characteristics	Temperature Characteristics: Add specified accuracy × 0.1/°C (when operating outside 18°C to 28°C).
	Example at 8°C:±0.2%rdg±10dgt (base accuracy) + 0.1×10 (temperature difference) × (0.2%rdg+10dgt) =±0.4%rdg±20dgt

Note: 1. Reference Conditions: Accuracy specified when Rh and Rs < 100Ω.
         Operating Conditions: Maximum Rh = 3kΩ + 100R < 50kΩ, Maximum Rs          = 3kΩ + 100R < 50kΩ

2.Accuracy depends on the measurement precision of R, π = 3.14,       a :0.1m–100.0m

2.General Specifications

Ambient temperature and humidity	23℃±5℃, below 75%rh
Interfering voltage	<20V (should be avoided)
Interfering current	<2A (should be avoided)
Electrode - to - electrode distance when measuring	a>5d
R
Electrode - to - electrode distance when measuringρ	a>20h
Power Supply	11.1V lithium - ion battery (built - in), can continuously measure in AC resistance mode when fully charged for more than 1000 times
Screen brightness	Controllable, users can adjust it according to the scene
Measurement method	Precision four - wire, three - wire method measurement, simple two - wire, selective, dual - clamp method to measure ground resistance
Measurement method details	Two - three - four - wire method measurement: Polarity - changing method, measurement current 42.0mA Max
	Soil resistivity: Four - pole method
	Selective measurement: Polarity - changing method, measurement current 42.0mA Max
	Dual - clamp method: Non - contact mutual induction measurement method, test current 40mA Max
	DC resistance: Polarity - changing method
	AC current: Average value rectification (clamp - type)
	Ground voltage: Average value rectification (between S - ES interfaces)
	DC voltage: Average value rectification (between S - ES interfaces)
Test voltage waveform	Sine wave
Test frequency	128Hz
Open - circuit Test Voltage	AC 30.0VMaxDC 30.0VMax
Electrode Interval Range	0.1m~100.0m
Display Mode	Color - display screen
Instrument Size	Length×Width×Height:277.2mm×227.5mm×153mm
Current Clamp Size	Length×Width×Height:101mm×27mm×214mm
Test Wires	4 pieces: 15m red, 15m black, 10m yellow, 10m green each
Simple Test Wires	2pcs: 1.5m redand 1.5m green each
Auxiliary Grounding Rod	4 pieces:φ10mm×200mm
Current Clamp	Banana plug×1, audio plug×1
Current clamp caliber	φ50mm
Current Clamp Leads	Length 2m
Measurement Time	ACcurrent: about 3 times/second
	Ground - to - earth voltage: about 3 times/second
	Grounding resistance, soil resistivity: about 10 seconds/time
USB Interface	Has a USB interface, and stored data can be uploaded to a computer through software
Bluetooth Connection	Yes, real - time monitoring, data reading and other functions can be carried out on a mobile phone
Data Line	USB communication line, 1.5m
Data Storage	500 groups, "FULL" symbol indicates that the storage is full
Overflow Display	Over- range displays "OL" symbol
Auxiliary Grounding Test	Has the function of auxiliary grounding resistance test, 0.00kΩ~200.00kΩ
Alarm Function	An alarm is issued when the measured value exceeds the set alarm value (buzzer alarm)
Automatic Power off	“APO”indicator, automatic power offafter 15 minutes (default)
Power Consumption	Screen brightness:190mA Max(maximum brightness)140mA Min(minimum brightness)
	Measurement:200mA Max(maximum brightness)150mA Min(minimum brightness)
Weights	instrument:1975g(include battery)
	current clamp:940g(2 pcs)
	test lead:1300g(includes simple test lead)
	auxiliary grounding rods:850g(4rods)
Working temperature and humidity	-10℃~40℃;80%rh or below
Storage temperature and humidity	-20℃~60℃;70%rh or below
Over-load Protection	Measurement of ground-to -earth voltage: H - E, S - E (port - to - port) AC 280V/3 seconds

Insulation Resistance	20MΩ or above (between the circuit and the shell 500V)
Withstand Voltage	AC 3700V/rms(between the circuit and the shell)
Electromagnetic Compatibility	IEC61326(EMC)
Safety Class	IEC61010-1 (CAT III 300V, CAT IV 150V, pollution degree 2); IEC61010-031;
	IEC61557-1 (earth resistance);
	IEC61557-5 (soil resistivity);
	JJG 366-2004 (earth resistance meter);
	JJG 1054-2009 (clamp-on earth resistance meter).

PRODUCT APPLICATION

Company Profile

ABOUT US

Refine On (Hebei) Electric Power Technology Co., Ltd. is located in the Mancheng High-tech Development Zone, Baoding. It is fully committed to the high-tech field of power system automation, specializing in the research and development of a series of products such as power system marketing measurement, operation and maintenance high-voltage testing, distribution network testing, power consumption inspection, and tools and meters. It is a technology-oriented enterprise integrating R&D, production, sales and service. The company provides instruments, meters and testing equipment related to power generation, transmission, transformation, distribution and sales. Provide sales of complete sets of instruments and equipment required for installation (repair, testing) of Grade one, Grade Two, Grade Three and Grade Four.

The company is equipped with various production, testing and inspection facilities, has a sound management system, and strictly adheres to the GB/T19001-2016 quality management system standard for production and operation. A number of high-tech instruments and equipment that meet the on-site requirements have been developed. At present, the products have been widely applied in multiple fields such as power, railway, mining, petroleum and chemical engineering.

The company has obtained the Quality management System certification certificate, 2 invention patents, 10 utility model patents and 20 software Copyrights. And it has established long-term and close cooperative relations with units such as Beijing Institute of Metrology, Beijing Electric Power Research Institute, and Hebei Institute of Metrology.

Refine On (Hebei) is committed to providing high-quality products and technical services to users and partners in the power system with its exquisite technology, excellent quality and perfect service.

Our main products include insulating oil tester series, insulating resistance tester, power quality analyzer, circuit breaker, relay protection tester, high-voltage generator, high-voltage capacitor, test transformer, transformer test series, etc.

Certifications

Packaging & Shipping

FAQ

FAQ

1. Insulating Oil Tester Series
1.1 What is the main function of the Insulating Oil Dielectric Strength Tester (80kv/100kv)?
Tests insulating oil's dielectric strength to detect impurities, moisture, or aging, ensuring safe operation of transformers and circuit breakers.

1.2 How often should the Insulating Oil Dielectric Strength Tester be calibrated?
At least once a year; shorten intervals for frequent use, harsh environments, or post-maintenance.

1.3 What is the difference between the Closed Cup Flash Point Automatic Tester and the Open Cup Flash Point Automatic Tester?
• Closed Cup: Tests in sealed containers; for low-flash oils (e.g., diesel) and sealed power equipment.

• Open Cup: Tests in open containers; for high-flash oils (e.g., insulating oil) and air-exposed scenarios.

2. Transformer Test Series
2.1 What can the Transformer Capacity Tester detect?
Detects transformer's actual capacity, no-load/load loss, no-load current, and impedance voltage; judges compliance and faults.

2.2 How to use the Transformer Tap Changer Tester?
1. Connect test lines to tap changer terminals per manual.

2. Power on, select test mode (e.g., resistance test).

3. View results; disconnect and power off after. (Note: De-energize and ground transformer first.)

2.3 What is the purpose of the Transformer Winding Deformation Tester?
Detects winding deformation (axial displacement, short circuits) from short-circuits or vibration; enables early maintenance to avoid accidents.

FAQ

3. Circuit Breaker Test Instruments
3.1 What are the differences between the Single-Chip Microcomputer and Industrial Computer Circuit Breaker Characteristic Testers?
• Industrial Computer: Stronger data processing, more tests (e.g., dynamic resistance), touch interface, and computer data communication.
• Single-Chip: Simple structure, low cost; for basic characteristic tests.
3.2 How to judge whether the Circuit Breaker Characteristic Tester is working normally?
1. Check power and indicator lights.
2. Run self-test; test a standard circuit breaker.
3. Confirm results are within allowable error. Stop use if self-test fails or errors are large.
4. Cable Fault Test Instruments
4.1 What types of cable faults can the Multiple Pulse Cable Fault Tester detect?
Detects low-resistance (short circuits), high-resistance (leakage), and open-circuit faults; locates faults via pulse reflection.
4.2 How to improve the accuracy of the Cable Fault Location Tester?
• Ensure correct, firm test line connections.
• Select proper test mode/parameters for fault type.
• Eliminate environmental interference; keep site clean/dry.
• Calibrate regularly.
• Test multiple times for complex faults; analyze results comprehensively.
5. Insulation Resistance Tester
5.1 What is the application scope of the High-Voltage Insulation Resistance Tester?
Tests insulation of high-voltage equipment (transformers, generators, cables, etc.); checks for moisture, dirt, or aging to support commissioning and maintenance.
5.2 How to (complete based on full content; core steps?

Store in dry environment, avoid impact; clean terminals before use; calibrate regularly to maintain accuracy.)