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MEWOI4250 Untie-free tower grounding resistance tester,measuring earth resistance in power transmission towers and substation meshes-MEWOI.cn
INTRODUCTION
The MEWOI4250 detachable pole and tower grounding resistance tester is specially designed and manufactured for measuring the grounding resistance of poles and towers on site. Transmission line towers usually have 2 or 4 down conductors. When using the ground pile method or the clamp meter method to measure the grounding resistance, the connection between the down conductor and the ground electrode needs to be disconnected, and the measurement operation is cumbersome and the workload is large. The instrument adopts the 4-clamp method to measure the grounding resistance value of the tower. There is no need to unbutton during the measurement. Wireless communication is used between the 4 current clamps and the host computer. The on-site measurement is fast and safe, which greatly reduces the work intensity of the operators and improves the work efficiency. The instrument can also use 2-wire method, 3-wire method and 4-wire method to measure grounding resistance, soil resistivity; AC current; grounding voltage. It has unique anti-interference ability and environmental adaptability, and has good consistency of repeated tests, ensuring high precision, high stability and high reliability of long-term measurement. The 4 current clamps configured by the instrument can be used independently as clamp ammeters for testing AC current. The MEWOI4250 free-to-open tower grounding resistance tester consists of a host, 4 current clamps, test leads, auxiliary grounding rods, communication cables, printers, etc. The host adopts a 7-inch color screen, and the test results are clear at a glance. The current clamp and the host use wireless communication. The instrument also has Bluetooth communication. After downloading the APP, you can test and view the test results on the mobile phone. The meter is equipped with a built-in printer to print test results on site. The instrument can store 100 sets of data, upload the test results through the host computer software, and realize the functions of reading, viewing, saving, reporting, and printing historical data. The instrument shell adopts a waterproof protective box, which is anti-collision, anti-drop, waterproof (protection grade IP65), sturdy, safe and durable. The instrument is also equipped with a large-capacity rechargeable lithium battery pack, which is especially suitable for use in outdoor construction sites |
Measurement Accuracy
Measurement function | Measuring range | Accuracy | resolution |
Ground resistance ( R ) (4 clamp method) | 0.10Ω ～ 20.00Ω | ±10%rdg±5dgt | 0.01Ω |
20.0Ω ～ 200.0Ω | 0.1Ω | ||
Ground resistance ( R ) | 0.10Ω ～ 20.00Ω | ±2%rdg±3dgt | 0.01Ω |
20.0Ω ～ 200.0Ω | ±2%rdg±3dgt | 0.1Ω | |
200Ω ～ 2000Ω | ±2%rdg±3dgt | 1Ω | |
2.00kΩ ～ 20.00kΩ | ±4%rdg±3dgt | 10Ω | |
Soil resistivity ( ρ ) | 0.00Ωm ～ 99.99Ωm | (ρ = 2πaR a : 1m ～ 100m ； π = 3.14) | 0.01Ωm |
100.0Ωm ～ 999.9Ωm | 0.1Ωm | ||
1000Ωm ～ 9999Ωm | 1Ωm | ||
10.00kΩm～99.99kΩm | (ρ = 2πaR a : 1 m ～ 100m ； π = 3.14) | 10Ωm | |
100.0kΩm～999.9kΩm | 100Ωm | ||
1000kΩm～9000kΩm | 1kΩm | ||
AC current (A～) | 1.00mA～50.00mA | ±2%rdg±3dgt | 0.01mA |
0.50A～5.000A | ±2%rdg±3dgt | 0.001A | |
5.0A～500.0A | ±3%rdg±3dgt | 0.1A | |
Ground voltage (V～) | 0.0V～200.0V | ±2%rdg±3dgt | 0.1V |
Technical Specifications
power supply | DC 7.4V 5200mAh rechargeable lithium battery, the battery is fully charged about 8.4V |
range | 4 clamp method to measure ground resistance: 200Ω |
Grounding resistance: 0.00Ω～20.00kΩ | |
Soil resistivity: 0.00Ωm～9000kΩm | |
AC current: 1.00mA～500.0A | |
Ground voltage: 0.0V～200.0V | |
Measurement methods | Tower grounding resistance: 4 clamp method |
Grounding resistance: rated current pole change method | |
Soil resistivity: quadrupole method (Wenner method) | |
AC current: clamp CT, RMS acquisition | |
Ground voltage: voltage division, RMS acquisition | |
Current clamp diameter | Φ68mm |
Test frequency | 128Hz/111Hz/105Hz/94Hz(AFC) |
Short circuit test current | AC 55mA max |
Open circuit test voltage | AC 15V max |
Test voltage waveform | sine wave |
display mode | 7-inch color screen, LCD size: 151mm×83mm |
Meter size | Height, width and thickness: 355mm×272mm×164mm |
Standard test lead | 4 strips: red 20m, black 20m, yellow 10m, green 10m 1 each |
Simple test lead | 2: Red 1.6m, 1 black 1.6m each |
Auxiliary ground rod | 4 pieces: φ10mm×250mm (about 935g) |
measure time | Grounding resistance, soil resistivity: about 30 seconds/time |
Communication Interface | With USB interface, software monitoring, storage data can be uploaded to the computer, save and print |
printer | built-in |
data storage | 100 groups, " 001/100 " storage indication, display " 100/100 " means the storage is full |
overflow display | " OL " symbol indicates when overrange overflow occurs |
Auxiliary ground test | With auxiliary ground resistance value test function, 0.00KΩ～20kΩ (100 R + rC<20kΩ, 100 R + rP <20kΩ) |
Alarm function | When the measured value exceeds the alarm setting value, the alarm symbol of “Sir” will prompt |
Automatic shut-down | 30 minutes after power on, automatic shutdown |
battery voltage | When the battery voltage drops to about DC 7.2V±0.1V, the low battery voltage symbol "" will be displayed to remind the meter that it needs to be charged |
Working current | Standby: about 400mA; measurement: about 550mA |
quality | Meter: about 2810g (including battery); current clamp: about 500g × 4; total mass: about 8800g (including accessories) |
Working temperature and humidity | -10℃～40℃; below 80%rh |
Storage temperature and humidity | -20℃～60℃; below 70%rh |
Overload protection | Measuring ground resistance: AC 280V/3 seconds between each port of C(H)-E and P(S)-ES |
Protection class | IP65 (with lid closed) |
Insulation resistance | Above 20MΩ (500V between circuit and case) |
Suitable for safety regulations | IEC61010-1 (CAT III 300V, CAT IV 150V, pollution degree 2); IEC61010-031; IEC61557-1 (grounding resistance); IEC61557-5 (soil resistivity); JJG 366-2004. |
