Description

Introduction Kyoritsu KEW 3125B High Voltage Insulation Tester

The Kyoritsu KEW 3125B High Voltage Insulation Tester stands as the gold standard for professional electrical insulation testing in Bangladesh and worldwide. Engineers and technicians who demand uncompromising accuracy choose this instrument because it delivers a wide test voltage range from 250V to 5000V and an insulation resistance measurement capacity of up to 1TΩ. The KEW 3125B combines advanced PI (Polarization Index) and DAR (Dielectric Absorption Ratio) diagnostic functions with a robust, ergonomic design that professionals trust in demanding field conditions. Its IEC 61010-1 CAT IV 300V / CAT III 600V safety certification guarantees operator protection at the highest level. Whether you work in power generation, industrial maintenance.

 

Specifications Kyoritsu KEW 3125B High Voltage Insulation Tester

Parameter	Value / Details
Model	KEW 3125B
Insulation Resistance Range	0.0MΩ to 1TΩ
Test Voltages (Selectable)	250V DC / 500V DC / 1000V DC / 2500V DC / 5000V DC
Accuracy (Insulation Resistance)	±5%rdg ±3dgt (standard range); ±20%rdg at 100GΩ or more
Output Voltage Accuracy	250V: ±10%; 500V: -10% to +20%; 1000V–5000V: 0% to +20%
Short-Circuit Current	Up to 1.5mA
Voltage Measurement Range (AC)	30V to 600V AC (50/60Hz)
Voltage Measurement Range (DC)	±30V to ±600V DC
Voltage Measurement Accuracy	±2%rdg ±3dgt
PI (Polarization Index)	Ratio of 10-min resistance to 1-min resistance; Criteria: ≥4.0 Best, 2.0–4.0 Good, 1.0–2.0 Warning, <1.0 Bad
DAR (Dielectric Absorption Ratio)	Ratio of 1-min resistance to 15-sec or 30-sec (user-selectable) resistance; Criteria: ≥1.4 Best, 1.0–1.25 Good, <1.0 Bad
Filter Function	Yes – reduces noise interference for stable readings
Guard Terminal	Yes – minimizes surface leakage current effect
Live Voltage Warning	Yes
Auto-Discharge	Yes
Lockable Test Button	Yes
Display	Large LCD with Bar Graph and Backlight
Power Source	LR14 (Alkaline battery size C) × 8 pcs, DC 12V
Applicable Safety Standards	IEC 61010-1, IEC 61010-2-030, CAT IV 300V / CAT III 600V, Pollution Degree 2
Other Standards	IEC 61010-031, IEC 61326-1, IEC 61326-2-2
Dimensions (Instrument)	177(L) × 226(W) × 100(D) mm
Dimensions (Hard Case)	380(L) × 430(W) × 154(D) mm
Weight (with batteries)	Approx. 1.9 kg
Weight (with accessories)	Approx. 4 kg
Country of Manufacture	Japan
Standard Accessories	Line probe 3m (7165A), Earth cord 3m (7264), Guard cord 3m (7265), Hook type prod (8019), Hard case (9181), 8× LR14 alkaline batteries, Instruction manual
Optional Accessories	Line probe with alligator clip 3m (7168A), Longer line probe with alligator clip 15m (7253), Adaptor for recorder – 1mV/1μA output (8302)

 

Key Features Kyoritsu KEW 3125B High Voltage Insulation Tester

The Kyoritsu KEW 3125B High Voltage Insulation Tester delivers an impressive set of features that set it apart from competing instruments.

1. Insulation Resistance up to 1TΩ – The device measures insulation resistance across a massive range, making it suitable for even the most demanding high-resistance applications.
2. Wide Test Voltage Range (250V to 5000V) – Five selectable test voltages (250V, 500V, 1000V, 2500V, and 5000V) give technicians full flexibility across different equipment types. As a result, a single instrument covers virtually all professional testing scenarios.
3. PI and DAR Diagnostic Functions – The built-in Polarization Index and Dielectric Absorption Ratio calculations assess insulation health over time. Furthermore, this automated diagnosis reduces human calculation errors and speeds up the assessment process.
4. Short-Circuit Current up to 1.5mA – A high short-circuit current of 1.5mA ensures efficient charging of large-capacitance cables and motors, so tests complete accurately even on long cable runs.
5. Noise-Reduction Filter Function – The integrated filter suppresses electrical noise interference, therefore delivering stable and reliable readings even in electromagnetically harsh environments.
6. Large LCD Display with Bar Graph and Backlight – The bright backlit display with analogue bar graph allows technicians to read results instantly in any lighting condition. Additionally, the bar graph shows resistance trends in real time.
7. Live Voltage Warning – The instrument alerts the operator immediately when it detects a live voltage on the circuit under test, consequently preventing dangerous measurement errors.
8. Auto-Discharge Function – After each test, the tester automatically discharges stored capacitive energy, so the operator and equipment stay safe during disconnection.
9. Lockable Test Button – The test button locks for hands-free continuous measurement, which reduces operator fatigue during extended testing sessions.
10. Newly-Designed Alligator Clip – The redesigned clip grips securely on large bolt heads up to 27mm, eliminating slippage during measurement.

 

Applications

The Kyoritsu KEW 3125B High Voltage Insulation Tester serves a wide range of demanding professional environments.

1. Power Generation Plants – Technicians use the KEW 3125B to test generator windings and transformer insulation, so plant operators can identify degradation before it leads to costly failures.
2. High-Voltage Motor Testing – The tester evaluates motor winding insulation at voltages matching real operating conditions. Furthermore, PI diagnostics reveal gradual insulation deterioration trends that visual inspection cannot detect.
3. Cable and Wire Insulation Testing – Engineers apply the device to long-run power cables to confirm insulation integrity before energizing new installations or after cable repairs.
4. Industrial Switchgear and Control Panels – Maintenance teams test switchgear insulation regularly with the KEW 3125B to prevent arc flash incidents and unexpected downtime.
5. Electrical Contractor Commissioning – Contractors use the instrument during final commissioning of industrial and commercial electrical systems to verify that all insulation meets specification before handover.
6. Preventive Maintenance Programs – Facilities managers schedule routine insulation testing with the KEW 3125B to track insulation health over years, thus extending equipment life and reducing emergency repair costs.
7. Power Utilities and Substations – Utility engineers rely on the 5kV test voltage to evaluate high-voltage substation equipment, including busbars, isolators, and protective relays.
8. Marine and Offshore Electrical Systems – The robust design and noise-rejection filter make the KEW 3125B suitable for shipboard electrical testing in electromagnetically challenging environments.

 

 

Who Uses This

The Kyoritsu KEW 3125B High Voltage Insulation Tester serves a professional audience that demands precise, reliable diagnostic tools.

1. Electrical Engineers – Design and testing engineers choose the KEW 3125B to validate new installations and perform FAT (Factory Acceptance Testing) on high-voltage equipment. Additionally, they use PI and DAR diagnostics to build long-term insulation health records for their assets.
2. Industrial Maintenance Technicians – Technicians in manufacturing plants and process industries use the device during planned maintenance shutdowns to test motors, transformers, and cables. As a result, they catch deteriorating insulation before it causes production losses.
3. Power Utility Workers – Substation and line crew personnel rely on the KEW 3125B’s 5kV capability and CAT IV safety rating to safely test high-energy utility equipment in the field.
4. Electrical Contractors and Installers – Contractors use the instrument to perform pre-energization insulation tests on large commercial and industrial installations, therefore ensuring compliance with local electrical codes before sign-off.
5. Testing and Inspection (T&I) Professionals – Third-party inspection engineers use the KEW 3125B to provide independent insulation resistance test reports for insurance, compliance, and asset management purposes.
6. Marine and Offshore Electrical Engineers – Ship electricians and offshore platform technicians choose this instrument for its robust construction and noise-filtering capability in harsh marine electromagnetic environments.
7. Renewable Energy Technicians – Solar and wind installation teams use the KEW 3125B to test insulation on photovoltaic arrays, cable runs, and turbine generator windings during commissioning and periodic maintenance.

 

Frequently Asked Questions (FAQ)

Q1: What is the maximum insulation resistance the Kyoritsu KEW 3125B can measure?

The KEW 3125B measures insulation resistance up to 1TΩ (one teraohm). This massive range covers even the highest-resistance measurements found in modern electrical systems.

Q2: What test voltages does the KEW 3125B support?

The device supports five selectable DC test voltages: 250V, 500V, 1000V, 2500V, and 5000V. Therefore, technicians can match the test voltage to the rated voltage of the equipment under test, ensuring accurate and safe diagnostic results.

Q3: What are PI and DAR, and why do they matter?

PI stands for Polarization Index and DAR stands for Dielectric Absorption Ratio. Both functions assess the condition of insulation by comparing resistance values measured at different time intervals. Specifically, PI compares the 10-minute resistance reading to the 1-minute reading, while DAR compares the 1-minute reading to a short-interval reading.

Q5: Does the KEW 3125B have an auto-discharge function?

Yes. After each insulation test, the instrument automatically discharges the capacitive energy stored in the circuit under test. This function protects both the operator and the test leads from unexpected electric shock during disconnection.

Q7: Can I use the KEW 3125B on solar PV systems in Bangladesh?

Yes. The 5kV maximum test voltage and 1TΩ measurement range make the KEW 3125B ideal for testing insulation on solar PV array cables, string junction boxes, and inverter connections. The noise-reduction filter also helps maintain stable readings in environments with switching noise from inverters.

Q8: Where can I buy the Kyoritsu KEW 3125B in Bangladesh?

You can purchase the Kyoritsu KEW 3125B High Voltage Insulation Tester directly from astzbd, Bangladesh’s trusted professional test equipment supplier. astzbd provides genuine Kyoritsu products with full documentation and after-sales support. Visit astzbd online or contact the team for current pricing and availability.

 

Why Buy from astzbd

astzbd stands as Bangladesh’s most reliable source for professional electrical test and measurement equipment, and there are clear reasons why engineers and technicians across the country choose astzbd for the Kyoritsu KEW 3125B and other instruments.

1. 100% Genuine Products – astzbd sources all instruments directly from authorized Kyoritsu distributors. Therefore, every KEW 3125B you purchase carries full manufacturer documentation and genuine calibration traceability.
2. Competitive Pricing for Bangladesh Market – astzbd understands the local market and offers fair, transparent pricing on professional test instruments. Furthermore, the team regularly reviews prices to ensure customers get the best value available in Bangladesh.
3. Fast Nationwide Delivery – astzbd dispatches orders promptly and delivers to Dhaka, Chittagong, Sylhet, Khulna, and all major cities across Bangladesh. As a result, you receive your instrument quickly and can start testing without unnecessary delays.
4. Expert Technical Support – The astzbd team includes technically qualified engineers who understand insulation testers and their applications. Consequently, you can call or message astzbd for pre-sale advice, technical questions, or after-sales support with confidence.
5. Secure and Easy Online Purchase – The astzbd website offers a straightforward, secure checkout process with multiple payment options including mobile banking, so you can order conveniently from anywhere in Bangladesh.
6. After-Sales Service and Warranty Assistance – astzbd assists customers with warranty claims and service coordination, so you are never left without support after your purchase.
7. Trusted Reputation in Bangladesh – Hundreds of electrical engineers, contractors, and industrial companies across Bangladesh trust astzbd as their preferred supplier for Kyoritsu and other leading test equipment brands. This track record of customer satisfaction reflects astzbd’s commitment to quality and service.