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Kyoritsu KEW 4105A EARTH TESTER Review
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Kyoritsu KEW 4105A Digital Earth Tester: Technical Review, Specifications & GCC Field Guide
A rugged, field-proven 2-pole & 3-pole earth resistance meter engineered for MEP contractors, utility substations, and industrial electrical grounding audits complying with IEC 61557 and BS 7671.
If you work in electrical installation, substation commissioning, maintenance, or safety inspection across the GCC, the Kyoritsu KEW 4105A Earth Tester is an industry-standard instrument for ground electrode resistance measurement. Built to withstand real-world industrial site conditions, it combines ultimate measurement accuracy with user safety, dust/drip protection, and rapid deployment capabilities.
In this comprehensive technical guide, we review the KEW 4105A’s core engineering principles, operating modes, verified accuracy tolerances, standard included accessories, and GCC authority compliance (DEWA, SEWA, ADDC, SEC) to assist procurement teams and testing engineers.
Core Engineering Strengths: The KEW 4105A delivers precision 3-pole & 2-pole earth loop resistance testing up to 2000Ω, 0–200V AC earth voltage detection, IEC 60529 IP54 dust & drip-proof housing, and an engineered 2 mA / 820 Hz test current that prevents nuisance tripping of sensitive residual current devices (RCD/ELCB).
| 2-Pole / 3-PolePrecision & Simplified Methods | 0–200V ACLive Ground Voltage Check | IP54 RatedDust & Water Splash Proof | 2 mA / 820 HzNon-Tripping Test Current |
What Is the Kyoritsu KEW 4105A Earth Tester?
The Kyoritsu KEW 4105A is a micro-controlled, high-precision digital earth ground resistance tester designed to verify the integrity of electrical earthing systems in compliance with IEC 61557-5, IEEE Standard 81, and BS 7671 (IET Wiring Regulations).
Engineered with advanced filtering circuits operating at an 820 Hz measuring frequency, the KEW 4105A suppresses commercial power frequency (50/60 Hz) interference and harmonic noise. This ensures accurate readings even when measuring grounding grids in energized electrical substations and industrial facilities with significant ground voltage potentials.
Field Diagnostic Benefit:
It detects residual ground voltage up to 200V AC prior to resistance measurement, preventing tester damage and warning technicians of hazardous stray voltage on earthing conductors.
It detects residual ground voltage up to 200V AC prior to resistance measurement, preventing tester damage and warning technicians of hazardous stray voltage on earthing conductors.
Comparison: Kyoritsu KEW 4105A vs. Other Ground Testers
To select the right grounding instrument for your testing requirements, see how the digital 4105A compares to the analog 4102A and the clamp-on 4200 model:
| Feature / Specification | Kyoritsu KEW 4105A (Digital) | Kyoritsu KEW 4102A (Analog) | Kyoritsu KEW 4200 (Clamp) |
|---|---|---|---|
| Display Type | Digital LCD (High Contrast) | Analog Needle Meter | Digital Backlit LCD |
| Testing Method | 2-Pole & 3-Pole (Fall of Potential) | 2-Pole & 3-Pole | Stakeless Clamp-on (CT) |
| Resistance Range | 20Ω / 200Ω / 2000Ω | 12Ω / 120Ω / 1200Ω | 0.05Ω to 1200Ω |
| Resolution | 0.01 Ω | Scale division | 0.01 Ω |
| Earth Voltage Range | 0–200V AC | 0–30V AC | Leakage Current (1000mA) |
| Ideal Use Case | MEP handover, DEWA/SEWA audits | Basic routine site checks | Paved sites & multiearthed grids |
Measurement Techniques: 3-Pole vs. 2-Pole Testing
Precision 3-Pole Method (Fall-of-Potential)Used for exact baseline earthing verification on new installations, earthing pits, and lightning rods:
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Simplified 2-Pole Method (Commercial Earthing)Ideal for urban environments, concrete floors, and established buildings where ground spikes cannot be driven:
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Key Engineering Features of Kyoritsu KEW 4105A
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Dual 3-Pole and 2-Pole Operating ModesSwitch between precision Fall-of-Potential testing using auxiliary spikes and 2-pole simplified testing for urban and asphalt environments using supplied probe adapters. |
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Noise Suppression & High Spike ToleranceThe latest internal circuit design tolerates high auxiliary spike resistance (up to several kΩ) and rejects 50/60 Hz stray earth voltage without losing reading precision. |
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3
IEC 60529 IP54 EnclosureEngineered with rubber-sealed battery compartments and splash-proof switches, built specifically for harsh outdoor desert dust and humidity conditions across the Middle East. |
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High-Contrast Custom LCD DisplayFeatures high-legibility digital digits, battery status indicator, earth voltage warning, and unit annunciators readable in direct sunlight. |
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Shock-Resistant Composite CasingWeighing only 550g with protective lid and neck strap, allowing full hands-free operation when working at distribution boards or earth pits. |
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2 mA Low Test Current (No-Trip Circuit)Performs reliable measurements without tripping upstream 30mA/100mA RCDs and ELCBs during routine building preventive maintenance. |
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7
0–200V AC Earth Voltage Safety InterlockMeasures ground potential prior to test execution, warning technicians if hazardous voltage exceeding 10V is present on the earthing conductor before injecting test current. |
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How to Test Ground Resistance with KEW 4105A (Field Procedure)
Follow this 4-step Fall-of-Potential standard verification procedure during on-site commissioning:
- Check Earth Voltage: Set the rotary selector switch to the EARTH VOLTAGE position. Connect Green (E) to the earth electrode. Ensure the measured stray voltage is below 10V AC. If voltage is higher, rectify the ground fault first.
- Drive Auxiliary Ground Spikes: Drive the Yellow auxiliary potential spike (P) into the soil 5 to 10 meters away from the earth electrode under test. Drive the Red current spike (C) 20 meters away in a direct line.
- Connect Test Leads: Connect Green lead to E terminal, Yellow lead to P terminal, and Red lead to C terminal.
- Execute Test: Turn the rotary dial to the 2000Ω range and press the PRESS TO TEST button (or lock it for continuous measurement). Step down to 200Ω or 20Ω range for optimal 0.01Ω decimal resolution.
Kyoritsu KEW 4105A Official Specifications
Standard Included Accessories
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Genuine Optional Accessories
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Looking for alternatives? Compare the KEW 4105A with top market models in our expert guide:
Top 5 Best Earth Resistance Testers for UAE Field Testing
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Primary Field Applications & Industry Use Cases
Electrical Installation & Utility Compliance
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Industrial Site Maintenance & Safety Verification
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Technical Advantages That Improve Usability
High Stability in Arid Desert SoilsInternal synchronous rectification and 820 Hz filtering suppress both auxiliary spike resistance errors and high soil resistivity variations commonly found in arid and sandy desert terrains. |
Compact Ergonomics & Hands-Free UseEquipped with a secure neck strap and lightweight housing (550 g), allowing commissioning engineers to operate push-to-test controls with both hands free to position test leads. |
Built-in Live Voltage WarningPrior to measuring resistance, the instrument displays ground potential up to 200V AC, protecting the internal circuits from burnout and safeguarding the operator from dangerous ground fault loops. |
Full Safety Compliance (IEC 61010-1 CAT III)Certified to IEC 61010-1 CAT III 300V, IEC 61557-1/-5, and CE standards, guaranteeing full compliance with municipal audits, consulting specifications, and safety documentation. |
Who Should Choose the Kyoritsu KEW 4105A?
The Kyoritsu KEW 4105A is the primary workhorse instrument for professionals who require certified grounding measurements across the GCC:
- MEP & Electrical Contractors: Handing over residential, commercial, and industrial electrical installations to local authorities.
- Testing & Commissioning Engineers: Requiring exact Fall-of-Potential documentation and resistance verification.
- Facility Maintenance Managers: Conducting mandatory periodic safety inspections on lightning protection and earthing pits.
- Solar & Telecom Field Technicians: Auditing distributed ground rods, counterpoise arrays, and inverter grounding beds.
Backed by Japanese engineering precision and full distributor calibration support from Mohammad Mahdi Electronics, the KEW 4105A delivers exceptional durability and unmatched cost-to-performance value.
Final Engineering Verdict
The Kyoritsu KEW 4105A Digital Earth Tester remains the undisputed gold standard for contractors and testing engineers across the Middle East. Combining robust IEC 60529 IP54 weather protection, dual 3-pole Fall-of-Potential and 2-pole simplified modes, RCD non-tripping 2 mA test current, and full compliance with IEC 61557, it guarantees fast, repeatable, and audit-ready grounding verification.
For commercial facilities, high-voltage substations, and MEP compliance inspections, the KEW 4105A delivers unmatched field reliability and long-term Japanese measurement precision.
Need Official Price & Fast GCC Stock Delivery?
Contact Mohammad Mahdi Electronics LLC for authorized Kyoritsu KEW 4105A stock availability, project bulk discounts, and ISO 17025 calibration certificates across UAE, Saudi Arabia, and Oman.
Get Price & Stock on WhatsApp / استعلام السعر والتوفر واتساب
Direct Sales Support: +971 4 447 6031
Is the Kyoritsu KEW 4105A approved by DEWA and SEWA
Yes. The KEW 4105A fully complies with IEC 61557-5, IEC 61010-1 CAT III 300V, and BS 7671 standards, making it widely approved and accepted by UAE municipal utilities including DEWA (Dubai), SEWA (Sharjah), and ADDC (Abu Dhabi) for MEP handover testing.
What is the difference between KEW 4105A and KEW 4105A-H
Both models feature identical electronics, accuracy, and specifications. The KEW 4105A comes packaged with a Model 9084 soft carrying case, whereas the KEW 4105A-H includes the Model 9165 heavy-duty hard plastic carrying case.
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