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Kewtech KEW3128 High Voltage Insulation Tester

The microcomputer controlled KEW3128 comes with everything you need for 12kV High Voltage Insulation Resistance and Diagnostic Test.

Next Day Delivery (subject to availability)

£5,595.00 excluding VAT £6,714.00 including VAT @ 20%
  • 12kV Tester
  • Rated IP65
  • Wireless Connectivity
  • Manufacturer Certificate Included
  • Internal memory
  • Capacitance and leakage measurements
  • Robust and portable
  • FreeDelivery
  • 30DayMoneyBack
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kewtech KEW3128 12kV High Voltage Insulation Tester


The Kewtech KEW3128 is a microprocessor controlled 12kVDC insulation resistance tester capable of providing insulation resistance values of up to 35TΩ.

Crucially, the KEW3128 is able to discharge dangerous capacitive charges, consequent when subjecting large DC voltages across inductive loads for set periods of time; allowing for safe testing of cable lengths and other HV equipment. Ideal for simple compliance testing and leakage current tests, the KEW 3128 can also be used to conduct more in depth diagnostic checks such as: PI - polarisation index measurements DAR - dielectric absorption ratio DD - dielectric discharge SV - step voltage measurement Test measurements can be viewed in ‘live time’ when connected to a PC or laptop, or on the instrument itself which features a large, 320x240 resolution graphical screen.

The in-built graphical screen can be scrolled through and zoomed in on specific points through the whole recording period (up to 90 mins), allowing for instant onsite diagnosis. Moreover, a ‘print screen’ function is provided enabling the user to record a Bitmap (.bmp) image of the screen. The Kewtech KEW3128 12kV tester features an impressive memory, capable of storing 40,000 measurements. When using and ‘KEW Windows’ software package, test data can be downloaded should further test verification or reports be required off-site.
The KEW3128 12kV tester is dual powered and can be operated from a mains supply or from an in-built re-chargeable battery. The insulation tester is supplied and can be operated from within a hard carry case that offers IP68 ingress protection (when the lid is closed), along with test leads, software and USB cable, calibration certificate and user manual.


Kewtech KEW3128 Comes Supplied With:

  • 7226 (Line probe)
  • 7227 (Line probe with alligator clip)
  • 7224 (Earth cord)
  • 7225 (Guard cord)
  • 7170 (Main cord)
  • 8029 (Extension prod)
  • 8212-USB-W (USB adaptor with KEW Windows(Software))
  • Instruction manual
  • Calibration Certificate


Key Features:

  • Microprocessor controlled high voltage insulation resistance tester with Diagnostic functions.
  • Suitable for analyzing the insulation characteristics of cables, transformers, motors, generators, high-pressure switches, insulators, wiring installations, etc.
  • High current for fast testing even with large capacitive circuits. 5mA short circuit test current.
  • Measures insulation resistance up to 35TΩ and has large graphic display
  • Memory and logging functions comes with dedicated application software
  • Filter function and capacitance and leakage measurements
  • Polarisation Index, Dielectric discharge, Dielectric Absorption, Step voltage measurement
  • 6 ranges: 500V, 1000V, 2500V, 5000V, 10000V, 12000V. Fine adjustment of voltage setting at each range is also possible.
  • Graphic representation of the insulation resistance and leakage current versus time on large display with bar graph and backlight.
  • Can be operated from built-in rechargeable battery or from AC line.
  • Automatic discharge after test with monitoring of the discharge voltage.
  • Internal memory can store about 40,000 data (max).
  • Robust design for field use with IP64 rating (with lid closed). 


ISSWWW and Kewtech

One of our longest standing manufacturer partnerships and a brand that sells well day in day out for solid dependability and innovation at the price point.
Kewtech manufacture innovative, accurate and reliable test equipment that enables UK electrical contractors to undertake their testing obligations quickly and efficiently.

A product with the “Kewtech” brand has been specifically designed for the UK market by a team with many years of industry experience. We pride ourselves on developing and manufacturing products that have real benefit to the industry.

Kewtech have consistently introduce industry firsts, like our Lightmate testing adaptors, the Pat Adaptor, the MFT with PAT testing plus download and our award winning RB1 Replacement Lamp. Our 17th Edition multifunction testers lead the way in ease of use, loop accuracy and repeatability of reading.

Kewtech KEW3128 High Voltage Insulation Tester
Insulation Resistance
Rated Voltage 500V 1000V 2500V 5000V 10,000V 12,000V
Max Measurement Value 500GΩ 1TΩ 2.5TΩ 5TΩ 35TΩ
Accuracy 0 - 50GΩ: ±5% rdg±3dgt (not guaranteed with setting of 250V or less) 100GΩ to 1TΩ: ±20% rdg 250GΩ to 1TΩ: ±20% rdg 500GΩ to 5TΩ: ±20%rdg 1T to 10TΩ: ±20% rdg
50G to 500GΩ: ±20%rdg (not guaranteed with setting of 250V or less) 10T to 35TΩ: values displayed, but accuracy isn't guaranteed
Short Circuit Current Max 5.0mA
Load Resistor to Output Rated Voltage 0.5MΩ or more 1MΩ or more 2.5MΩ or more 5MΩ or more 20MΩ or more 24MΩ or more
Output Voltage
Rated Voltage 500V 1000V 2500V 5000V 10,000V 12,000V
Monitor Accuracy ±10%±20V
Output Accuracy 0 to +20% 0 to +10% 0 to +10% 0 to +10% -5 to +5% -5 to +5%
Selectable Range 50 to 600V (in steps of 5V) 610 to 1200V (in steps of 10V) 1225 to 3000V (in steps of 25V) 3050 to 6000V (in steps of 50V) 6100 to 10,000V (in steps of 100V) 10100 to 12000V (in steps of 100V)
Voltage Measurement
Measuring Range DC voltage: ±30 to ±600V
AC voltage: 30 to 600V (50/60Hz)
Accuracy ±2% rdg ±3dgt
Current Measurement
Measuring Range 5.0nA to 2.40mA (depending on the insulation resistance)
Capacitance Measurement
Measuring Range 5.0nF to 50.0μF
5.0nF to 1.0μF (display range: 5.0nF to 50.0μF)
Accuracy ±5% rdg ±5dgt
General Specifications
Withstand Voltage AC8770V: between line terminal and enclosure/5 seconds (50/60Hz)
AC6880V: between the measuring terminal and enclosure / 5sec (50/60Hz)
AC2330V: between the power connector and enclosure / 5sec (50/60Hz)
Operating Temperature and Humidity Range -10 to 50°C (RH: 85% or less - when operating with an external power supply, no condensation)
0 to 40°C (RH: 85% or less - when operating with battery, no condensation)
Storage Temperature/Humidity -20 to 60°C (RH: 75% or less - no condensation)
Applicable Standards IEC 61010-1 CAT IV 600V
Pollution Degree 2
IEC 61010-031
IEC 61326
IEC 60529 (IP64) - with lid closed
Power Rechargeable lead storage battery (12V)
Charging time: approx 8 hours
AC Power Supply: 100 to 240V (50/60Hz)
Continuous measuring time approx 4 hours with a load of 100MΩ at the insulation resistance 12,000V range
Dimensions 330 (L) x 410 (W) x 180mm (D) - instrument + hard case
Weight 9kg approx (including battery) - instrument + hard case

Orders requiring calibration 

Whilst we take the greatest care to get all orders dispatched and delivered to you in the stated time frame, orders received PM and requiring
calibration may on occasion miss dispatch that day, according to the complexity of the calibration. Be assured they will ship on the next dispatch
this in most cases should not add more than 24 hours to your delivery.

Bank/Public Holidays

Predicted delivery times are based on regular trading days Monday to Friday. Public holidays, bank holidays and weekends are outside the usual scope 
of our dispatch and subject to activities/holidays of our carriers and therefore may incur additional days lead time to your order.

*UK Mainland (Temporarily revised June 2020)

Please note that regrettably, we have had to realign our delivery service options to those available from our carriers.
During the current situation surrounding the effects of the Coronavirus pandemic, logistics from every company are under immense pressure to deliver goods on time.
We have taken the decision to temporarily limit our services rather than let our customers down.
We hope you will understand our position on this and we apologise unreservedly for the inconvenience we know this will cause.
We look forward to restoring our full delivery service schedule just as soon as we are able.

Standard FREE 1-2 Day Courier Delivery – UK Mainland only - Zones A & B

Included in the price for all orders over £75.00 (exc vat). Sent using express courier, delivered within 1-2 working days from the date of your order, subject to availability.


Next Day Anytime Delivery (Excluding Saturday & Sunday) – UK Mainland only - Zones A & B
Sent by express courier, delivered next day (excluding weekends) from the date of your order, subject to availability.


Orders must be placed before 3:00pm for a qualifying next day delivery and a telephone number supplied, subject to availability.

New Postage Map Sept 2018>

Delivery Surcharges

Because of the high cost of carriage, we need to apply a surcharge on all deliveries made in the following regions bringing the carriage charges to:

  • Zones A & B  - Mainland delivery rates apply. 
  • Zone C - Scottish Highlands (Charges are calculated at the checkout).
  • Zone D - Outer Hebrides, Orkney Isles, Shetland Isles, Isle of Man, Scilly Isles, and Channel Islands (Charges are calculated at the checkout).
  • Zone E - Northern Ireland (Charges are calculated at the checkout).
  • Zone F - Republic of Ireland (Charges are calculated at the checkout).

Offshore Services

All offshore deliveries are a 2 day service as standard. This includes Channel Islands, Northern & Southern Ireland, Scottish Islands, Isle of Man and the Scilly Isles.

International Delivery

International delivery charges are automatically added to your order at the checkout. For any questions regarding international deliveries please contact us at


All export inquiries should be directed to the export division before placement of order.

If no shipping option is available to your selected country please call us FREE on 0800 0224 060 to purchase your items.
All stated prices are subject to VAT at the current rate where applicable E&OA