Megger MIT420 Insulation and Continuity Tester

The new Megger MIT400 series insulation and continuity testers has been designed for electrical testing by the utilities, industrial, commercial and domestic electricians. The wide range of features also makes the MIT400 series ideal for the maintenance and service/repair engineer. They replace the well-established BM400 insulation tester range, given greater functionality with simplified operation.

► CATIV 600V applications
► Insulation testing to 1000V and to 200GΩ
► TRMS & DC Voltage measurement
► Continuity testing at 200mA down to 0.01Ω
► Analogue and dual digital display
► Insulation & continuity limit alarms
► PI/DAR and Timer function
► Test result storage 

Insulation Testing
► Test voltages 250V to 1000V insulation test voltages available
► Test Lock locks insulation test on continuously.
► Actual test voltage is displayed on the smaller digital readout.
► The insulation result on the larger digital display.
► Analogue arc display to replicate the response of a moving coil display. 
► Polarisation Index (PI) and Dielectric Absorption Ratio (DAR) functions
► Insulation testing from 10GΩ to 200GΩ
► High quality flexible silicone test leads prevent measurement errors on higher GΩ ranges.
► Test inhibit prevents testing if voltages in excess of 50 V are detected.
► Insulation buzzer can be set to buzz if the insulation resistance is above a preset limit.

Continuity Testing
► Auto test on circuit contact.
► 200mA or 20mA continuity test currents are available.
► 20 mA test current will considerably increase battery life.
► Lead null - Lead resistance compensation (NULL) operates up to 9 Ω of resistance.
► Buzzer ON-OFF selected by simple push button.
► Continuity buzzer limit alarm is adjustable from 1 Ω to 20 Ω in 5 steps.

Analogue arc display
► Full display width analogue arc.
► Patented arc display shows charge and discharge characteristics not visible on a digital display.
► Single pointer “needle” response is similar to a moving coil meter.
► Logarithmic display for better low insulation value measurements.

Dual digital display
► Large main digital readout for good visibility of all main measurement results
► Second digital display for additional data such as:
     Insulation test voltage.
     Insulation leakage current.
     Supply frequency (when measuring volts).
     Test mode eg. PI, DAR or TI (Timed mode).

Storage & Downloading Results
►The MIT420 is capable of saving test results for recall to the screen. A simple storage structure allows for a test number and screen results to be recalled individually.

Safety
Designed to be exceptionally safe to use, fast detecting circuitry prevents damage to the instruments if accidentally connected to live circuits or across phases. Specifically, all instruments:

► Meet the international requirements of IEC1010-2 and EN61557.
► Live circuit detection inhibits insulation testing on circuits above 50 V.
► Live circuit detection and test inhibit on continuity measurements.
► Default display of live circuit voltage on all ranges.
► Detection and inhibit functions even if the protection fuse has failed.
► Suitable for use on CAT IV applications and supply voltages to 600 V.

Notes:
(1) All ranges measure from 0,00 MΩ upwards.
(2) Above specifications only apply when high quality silicone leads are being used.

Continuity
Measurement:
►0,01 Ω to 99,9 Ω (0 to 100 Ω on analogue 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:
►0,10 Ω typical
Lead resistance zeroing:
►Up to 9,00 Ω
Buzzer:
►Variable limit 1 Ω, 2 Ω, 5 Ω, 10 Ω, 20 Ω

Resistance
Measurement:
►0,01 kΩ to 1000 kΩ (0 to 1 MΩ on analogue 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 Analogue scale
►Unspecified input level 0 - 10 mV (40 to 400 Hz)
For non-sinusoidal waveforms additional specification apply:
►±3% ±2 digits 101 mV to 600 V TRMS and ±8% ±2 digits 10 mV to 100 mV TRMS
Default Voltmeter:
►Operates at >25 V a.c. or d.c. on any range except OFF
Frequency:
►40-450 Hz (40 Hz - 99,9 Hz)
►±0.5% ±1 digit (100 Hz to 450 Hz)

Capacitance measurement
►Measurement range: 100 pF to 10 μF
►Accuracy: ± 5.0% ±2 digits Distance by capacitance:
Arithmetic conversion from capacitance measurement on
►Default capacitance measurement: 50nF/m
►Capacitance range: 40 nF/m to 60 nF/m
 

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

Dimensions
Instrument:
►220 x 92 x 50 mm (8.66 in. x 3.63 in. x 1.97 in.)
Instrument + case:
►456 x 178 x 89 mm (18 in. x 7 in. x 3.5 in.)

Weight
Instrument only:
►590 gms, 775 gms with boot (20.73 oz.(27.22 oz.)
Instrument plus case:
►1.75kg (3.86 lb)

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
The instruments meet EN 61010-1 (1995) to 600 V phase to earth, Category IV. Refer to safety warnings supplied

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
Maximum altitude:
►2000 m
Dust and water protection:
►IP54 Protected against dust and splashing water