Megger MIT420/2 Insulation and Continuity Tester

The Megger MIT420/2 is a handheld insulation and continuity tester designed for use across electrical, industrial, automotive, and avionics applications. As part of the MIT400/2 series, it offers selectable test voltages of 50V, 100V, 250V, 500V, and 1000V, enabling insulation resistance measurements up to 200 GΩ. It features advanced diagnostic functions including Polarization Index (PI), Dielectric Absorption Ratio (DAR), and timed insulation tests. The tester also supports continuity testing from 0.01 Ω to 10 MΩ, frequency measurements from 15 to 450 Hz, and AC/DC voltage measurements up to 600V. Safety is prioritized with CAT IV 600V and IP54 ratings, live circuit detection, and auto polarity reversal. The MIT420/2 includes a switched probe for one-handed operation, PASS/FAIL alarms, and a redesigned rugged case with a six-cell battery compartment. It runs on standard AA or rechargeable NiMH batteries and is engineered for high accuracy and reliability in demanding environments.

Features and Benefits

• Adjustable insulation test voltage of 50 V, 100 V, 250 V, 500 V and 1000

• 600 V Trms AC and DC voltage measurement

• Insulation testing up to 1000 V and 200 GΩ range

• PI, DAR, Variable voltage, PASS/FAIL on limit alarms

• Capacitance 0.1 nF - 10 µF

• Frequency measurement 15 - 400 Hz

• On board memory

• Stabilized insulation test voltage

• Single range, faster continuity testing from 0.01 Ω to 1 MΩ

• Auto reverse polarity (setup ON-OFF)

• New case design with optional magnetic hanging strap

• Live circuit detection and protection

• CAT IV 600 V and IP54 weatherproof rating

• PASS/FAIL on limit alarms

• Language Group: LG2, English, Spanish, Portuguese and Italian

• Designed for Electrical and Industrial testing

Electrical and Industrial Maintenance Uses

The MIT420/2 includes diagnostic insulation tests like Polarization Index (PI) and Dielectric Absorption Ratio (DAR), enabling engineers to monitor motor performance trends. This makes the series an excellent choice for industrial maintenance professionals who need to schedule maintenance or provide solid justification for removing a motor from service.

Continuity - The Opposite of Insulation

With a continuity test, you’re looking to make sure that your circuit is isolated, and all of the connections are continuous. With the MIT420/2 tester, continuity testing is now fully automatic from 0.01 ohms to 1 MΩ with fast contact detection while continuously protecting against accidental contact with live circuits. The tester features a “buzzer” function, which sounds a tone when continuity is achieved.

Wind and Solar Applications

The MIT400/2 series has demonstrated reliable performance within the renewable energy sector (when paired with a PV test lead kit). These testers have been effectively applied in both wind and solar systems, covering components such as generators, cabling, and combiner boxes. With the Megger MIT400/2 insulation testers, you can detect pinched wires and leakage issues early—before they pose serious risks.

MIT400/2 Series CAT IV Insulation Testers

The MIT400/2 Series replaces the original MIT400 instruments and introduces a redesigned case, back stand, and six-cell battery compartments with dedicated fuse access. All four models feature over-molded construction for enhanced durability and carry an IP54 weatherproof rating. Additionally, continuity testing is now much faster, thanks to a single auto-ranging function covering 0.01 Ω to 1.0 MΩ, which replaces the previous 'ohms' and 'kOhms' ranges. The 200 mA and 20 mA test options remain available.

What's in the Box

• MIT 420/2 Insulation Tester

• Silicone leads (red/black)

• SP5 remote switch probe

• Batteries 6 x AA Alkaline

• Carry case

• Calibration certificate

Questions and Answers

• What are the application uses for the MIT400/2 Series?
  The MIT400/2 series of insulation testers are perfect for industrial maintenance and utility applications. They are CAT IV rated, allowing for instrument connection outside the building, have a higher energy available under fault condition and are defined by IEC61010.

• Why should you use an insulation tester and measure for insulation resistance?
  Insulation resistance (IR) measures the quality of your insulation and provides an overall assessment of your electrical equipment’s health. The top five reasons to use an insulation tester are that it helps extend the life of your equipment, saves money by preventing unexpected failures, is quick and easy—usually taking about one minute—won’t damage your equipment or reduce its lifespan, and there is a tester available for every budget, measurement range, and voltage requirement.

• What tests can be performed with a MIT420/2 tester?
  The MIT420/2 insulation tester provides Dielectric Absorption Ratio (DAR) and Polarization Index (PI) functions. DAR is a ratio derived from two results at particular points in time during a test. It has the advantage of being quick, sometimes no more than 60 seconds, and can be seen as independent of temperature. A popular DAR test is the PI Test. Two measurements are taken, at 1 minute and at 10 minutes, and these results are used to calculate a PI ratio.

• Does the MIT420/2 have storage or Bluetooth for data transfer?
  The MIT420/2 does have on board memory but it is not wireless. If preferred, the Megger MIT430/2 insulation tester provides Bluetooth pairing and storage. Test results can be downloaded to a CSV file which can then be opened as an Excel spreadsheet.