MEGGER MIT400 Datasheet

Megger – Datasheet
Industrial Insulation testers

General features

o Insulation testing to 1000V and to

200Gohms

o Continuity testing at 200mA down to

0.01ohms

o Analogue and dual digital display
o Insulation & continuity limit alarms
o PI/DAR timer function
o Test data storage and downloading
o AC/DC Voltage measurement
o Alkaline or rechargeable batteries
o CATIII 600V or CATIV 600V
o Calibration certificate

Introduction

The new Megger Industrial insulation and continuity testes combine the latest range of
measurement techniques with new instrument design to provide a state-of-the-art tester
that is compact and comfortable to hold.
The MIT400 series directly replaces the BM400, BM80 and indirectly replace the
BMM2000 and BMM2500 series, given greater functionality with simplified operation.

The range

The range consists of six instruments, which can be broken into 3 groups:

Industrial applications Telecoms Special apps

MIT400 MIT480 MIT40X
MIT410 MIT481
MIT420
MIT430

Every tester is designed to meet the stringent international requirements of IEC1010-2 as
well as those for EN61557, and sealed to IP54, providing a weatherproof case to reduce
the chances of water ingress, including the battery and fuse compartment.
Rubber over moulding combines the tough shock absorbing outer protection with excellent
grip, on a strong modified ABS housing, providing an almost indestructible case.
Battery requirements are 5 AA batteries of either standard Alkaline or Nickel Metal Hydride
(NiMH) rechargeable type.

Operation

Operation of all instruments is kept simple. All functions are displayed on the range
selector, with addition push-buttons under the display.

Main measurement selection is by rotary knob for all main test functions.

The display has a major and minor 31/2 digit readout, plus an analogue arc. All primary
results are displayed in the larger digits. Additionally, auxiliary test information such as
frequency, leakage current, Insulation or x`circuit voltage etc is displayed in the smaller
secondary 3 ½ digit display within the main window.

Insulation testing

The insulation test voltages range from 10 V to 1000V depending on model. Insulation
resistance measurement extends from 20Gohm to 200Gohm, with the option to display the
insulation leakage current on the MIT410, MIT420 and MIT430.
A buzzer threshold permits an operator to set a minimum buzzer limit. If the insulation
resistance exceeds the minimum limit the buzzer sounds without the operator having to
check the actual measured value.
Timed insulation testing of 30/60 seconds and 1min/10min for PI/DAR testing is also
available on the MIT410 upwards, but excludes the MIT480.

Variable insulation voltage (MIT400). (This is an example security method, which may
be modified on the final design.) To set the test voltage, turn to MΩ and press the ‘up’
button. Use the ‘left’, ‘down’ and ‘right’ buttons to enter a security code number. Press ok.
Without test leads connected, press TEST and observe the terminal voltage in top left
hand corner of display. Use the ‘up’ and ‘down’ buttons to set the desired open circuit
voltage and press ‘ok’.

This can only be changed by entering the correct security code.

Continuity testing
A 200mA continuity test is available with a resolution to 0.01ohms for fast accurate cable
resistance measurement.
Alternatively a buzzer range can be used for fast point-to-point testing where
measurement is not required.
Selectable buzzer threshold aids fast testing where measured values are not to be
recorded, only a pass fail at a specified limit is required, with the option to disable buzzer
sounding if required.

Special applications

The MIT40X has a special applications voltage, selectable from 10V to 100V in 1V steps,
depending on the application. Once selected this can be locked into the instrument and
not changed unless secret squirrel power-up is performed.

Storage & Downloading results

The MIT420 is capable of storing test results for recall to the sreen. A simple storage
structure allows for a test number and screen results to be recalled individually.

The MIT430 and the MIT481 support test result storage and downloading.

For these instruments the result storage allows approximately 3000 results to be stored
under a Job, Distribution board, circuit and phase structure, and is supplied with the
Megger download manager CD.

Data transfer is by Bluetooth, using either internal Bluetooth enabled PC’s or the USB
ports available on a PC with a Bluetooth dongle.

The MIT430 and MIT481 will have a Bluetooth transceiver built-in, offering excellent
isolation from the test circuit, and utilising the convenience of wireless operation.

Applications: CATIII and CATIV

All MIT400 instruments are rated to CATIV 600V (or CATIII 1000V).
The testers are optimised for different industrial applications. These have been grouped
into the following:

o Service, maintenance and electrical installations
o Telecommunications
o Special applications

(A) Service maintenance and electrical installations testing:

The MIT400, MIT410, MIT420 and MIT430 include all the features required for
engineers working in a range of industries including:

Domestic and industrial service and maintenance

Manufacturing/production testing

Electrical installation
Panel building
Rail

(B) Telecommunications testers

Designed to cope with the additional requirements of the Telecommunications
industry, the MIT480 series includes lower range insulation testing as standard,
plus higher voltages if required.
Required to achieve TNV3 requirements.
Measurement of cable distance by capacitance measurement provides fast cable
length testing without the need to use TDR technology.

(C) Special Applications

The MIT40X provides a unique solution for awkward insulation voltage
measurement applications. Typical test voltages are 10V, 35V, 50V, 55V, 65V, 75
etc found in diverse applications including:

Commercial Avionics
Military Land, Marine and Air
Communications
Manufacturing