Megger MIT400
250/500/1000 V CAT IV Insulation & Continuity Tester
See: MIT4002

  • Insulation testing up to 1000 V and 20 GΩ
  • Patented analog arc and dual digital display
  • CAT IV 600 V rating
  • TRMS & DC Voltage measurement
  • Continuity testing at 200 mA or 20 mA down to 0.01
  • Pass/Fail limit alarms
  • PI/DAR and Timer function
  • Three year product warranty
  • IP54 rated
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Megger MIT400 Shown
Product Information
Datasheet 163 KB PDF
CATV Booklet 1.03 MB PDF
PDF HelpPDF Help

The Megger MIT400 250/500/1000 V CAT IV Insulation & Continuity Tester has been designed for electrical testing by power utilities, industrials, telecommunication companies, commercial/domestic electricians and anyone with unique test voltage requirements. The wide range of features also makes the Megger MIT-40X ideal for maintenance technicians and engineers.

The Megger MIT 400 replaces the well-established BM400 insulation tester range, giving greater functionality with simplified operation, greater application range and increased safety.

Industrial and Power Electrical Installation Testing:
The Megger MIT400 includes all the features required for electricians, technicians and engineers working in a range of industries. Available features are selected to make testing easy and fast in a range of situations. Typical applications include:
  • Building/Campus electrical maintenance
  • Large and small scale electrical installations
  • Periodic electrical systems inspection and testing
  • Cable testing
CAT IV 600 V rating Provides greater safety when testing at higher voltage levels
Adjustable insulation test voltages Provides 250 V to 1000 V or 50 V to 1000 V.
Dual digital display readout Allows display of complimentary test information simultaneously (for example: MΩ plus test voltage or MΩ plus leakage current)
Digital and analog arc display Includes not only the digital readout but also Megger’s patented analog arc to replicate the response of a moving coil display
Exceptional measurement range from 20 GΩ to 200 GΩ Highest insulation test range available on the market, providing a superior range of measurement applications.
Choice of 20 mA or 200 mA continuity testing Allows user to select lower continuity range thus increasing battery life considerably
Continuity auto-test capability Enables real two-handed operation without the need to press the test button
Adjustable continuity limit alarm Allows pass/fail limits to be sent to speed testing
Automatically perform PI and DAR tests User is able to quickly perform two important diagnostic tests... Polarization Index (PI) and Dielectric Absorption Ratio (DAR)
True RMS voltage measurement Allows accurate voltage measurement on noisy lines
Auto ranging voltage measurement Automatically adjusts range from millivolts to 600 V AC or DC, eliminating the need to keep changing ranging
Live circuit warning Automatically warns of contact to a live circuit, voltage is displayed and testing is inhibited
Auto fuse warning Warns of fuse failure automatically. No need to test the fuse manually.
Buzzer select button Enable or disable buzzer as required with resistance also displayed on the screen

Instrument Safety
The Megger MIT400 is designed to meet all of the requirements of IEC1010-2 and EN61557 and meets the safety requirements for use on CAT IV 600 V.

Specific safety features include:
  • Any live circuit detection inhibits any insulation testing on circuits above 50 V (75 volts on Telecom models)
  • Any live circuit detection and test inhibit on continuity measurements
  • Default display of live circuit voltage on all ranges
  • Detection and inhibit features function even if the protections fuse has failed

Also, fast detection circuitry prevents damage to the instruments if accidentally connected to live circuits or across phases.

Instrument Dual Digital Display
The Megger MIT/400 offers an impressive dual digital display readout. The Megger MIT400 allows complimentary information to be displayed simultaneously such as:
  • MΩ plus test voltage
  • MΩ plus leakage current
  • Capacitance plus cable length (a test measurement for telecom applications)
The second digital display simultaneously displays the following information, depending upon the mode of operation or function chosen:
  • Insulation voltage being delivered
  • INS test modes
  • Leakage current
  • Test current
  • Timer modes
  • Countdown times
  • Cable length
Insulation Nominal test voltages 250 V, 500 V, 1000 V
Insulation resistance range 20 GΩ
Range Full Scale Accuracy 1000 volts ±3%, ±2 digits, ±0.2% per GΩ
500 volts ±3%, ±2 digits, ±0.4% per GΩ
250 volts ±3%, ±2 digits, ±0.8% per GΩ
100 volts ±3%, ±2 digits, ±2.0% per GΩ
50 volts ±3%, ±2 digits, ±4.0% per GΩ
10 volts ±3%, ±2 digits, ±2.0% per 100 MΩ
Analog range 1 GΩ full scale
Short Circuit Current 2 mA +0% -50%
Terminal voltage -0% +20% ±1 V
Test Current on load 1 mA at min. pass value of insulation specified in BS7671, HD384 and IEC364, 2 mA max.
EN61557 Operating range 0.10 MΩ to 1.00 GΩ
Leakage Current 10% ±3 digits
Voltage display 3% ±3 digits ±0.5% of rated voltage
Polarization Index (PI) 10 min/1 minute ratio
Dielectric Absorption Ratio (DAR) 60 sec/30 sec ratio
Continuity Measurement 0.01 Ω to 99.9 Ω (0 to 100 Ω on analog scale)
Accuracy: ±3% ±2 digits (0 to 100 Ω)
Open circuit voltage 5 V ±1 V
Test current 200 mA (–0 mA +20 mA)
(0.01 Ω to 9.99 Ω)
20mA (±1 mA)
(10.0 Ω to 99.9 Ω)
Zero offset at probe tips 0.10Ω typical
Lead resistance zeroing Up to 9.00 Ω
Buzzer Variable limit 1Ω, 2Ω, 5Ω, 10Ω, 20Ω
Resistance Measurement 0.01 kΩ to 1000 kΩ (0 to 1 MΩ on analog scale)
Accuracy ±3% ±2 digits
Open circuit voltage 5 V ±1 V
Short circuit current 20 µA ± 5 µA
Voltage range 0 to 600 V d.c. ±2% ±2 digits
10 mV to 600 V TRMS sinusoidal (40 to 400 Hz) ±2% ±2 digits
0 to 1000 V on Analog scale
Unspecified input level 0 - 10 mV (40 to 400 Hz)
Result storage Capacity >1000 test results
Download Bluetooth wireless
Bluetooth Class Class II
Range up to 10 m
Power Supply: 5 x 1.5 V cells type IEC LR6 (AA, MN1500, HP7, AM3 R6HP) Alkaline NiMH rechargeable cells may be used.
Battery life 2200 insulation tests with duty cycle of 5 sec ON /55 sec OFF @ 1000 V into 1 MΩ
(Instrument and case)
18 in. x 7 in. x 3.5 in. (456 x 178 x 89 mm)
(Instrument and case)
3.86 lb (1.75kg)
Fuse Use only a 500 mA (FF) 1000 V 32 x 6 mm ceramic fuse of high breaking capacity HBC 50 kA minimum. Glass fuses MUST NOT be fitted.
Safety Protection Meets EN 61010-1 (1995) to 600 V phase to earth, Category IV
E.M.C In accordance with IEC 61326 including amendment No.1
Temperature effects
(Temperature coefficient)
<0.1% per °C up to 1 GΩ
Environmental Operating range -10 to +55°C
Operating humidity 90% RH at 40°C max.
Storage temperature range -25 to +70°C
Calibration Temperature +20°C
Maximum altitude 2000 m
Dust and water protection IP54 Protected against dust and splashing water
Ordering Information
Model Description Buy Now Price
MIT400-EN Megger MIT400 250 V/500 V/1000 V CAT IV Insulation and Continuity Tester Discontinued
See: MIT4002
Related Products
MIT410-EN Megger MIT410 50 to 1000V Insulation and Continuity Tester Discontinued
See: MIT4102
MIT420-EN Megger MIT420 50 to 1000V Insulation and Continuity Tester Discontinued
See: MIT4202
MIT430-EN Megger MIT430 50 to 1000V Insulation and Continuity Tester with PI, 200GOhms Discontinued
See: MIT4302
MIT40X-EN Megger MIT40X 10 V to 100 V (in 1 V steps) CAT IV Insulation and Continuity Tester Discontinued
MIT480-EN Megger MIT480 50V / 100V Insulation and continuity tester Discontinued
See: MIT4812
MIT485-EN Megger MIT485 50V to 1000V Ins and Cont tester + Capacitance and cable length+ result storage and downloading Discontinued
See: MIT4852
Included Accessories
  • 1 - Red/Black silicone test lead set with crocodile clips
  • 1 - Hard carry case
  • 1 - Instrument rubber boot with built-in stand
  • 1 - Calibration certificate
  • 1 - User's Manual
Optional Accessories
6220-812 Megger 6220-812, SP5 Remote Switch Probe for MIT400 Series Discontinued
6220-813 Megger 6220-813, Replacement Lead Set for MIT400 Series Discontinued
See: 1002-001