Megger MIT300 MIT Series Insulation Resistance Testers

Megger MIT300 Series is a range of insulation and continuity testers developed specifically to meet the needs of today's electrical contractors. These instruments combine durability with ease of use, featuring an extensive range of safety features designed to protect the operator even in cases of accidental misuse .

The series includes five models: MIT300, MIT310, MIT310A, MIT320, and MIT330. The MIT300, MIT310, and MIT320 feature a popular digital/analogue display with 20mm high characters for clear readout, combined with an analogue arc that provides the feel of a true analogue instrument . The MIT310A offers a traditional moving coil display for those who prefer a real analogue needle .

Key Features

Rugged and Durable Design

Rubber Armoured Case: Designed to withstand the rough handling typical on job sites 

Protective Cover: Rigid display cover folds out of the way during testing and locks down to protect the display when not in use 

IP54 Weatherproof Rating: Protected against dust and water splashes 

Megger Intelligent Safety System

Safety Interlock: Prevents unsafe connection of test leads 

Live Voltage Warning: Alerts the operator when circuit voltage exceeds 25 V 

Safety Lockout: Inhibits testing when circuit voltage exceeds 50 V 

Continuity Check: Prevents continuity or buzzer tests on live circuits 

Automatic Discharge: Tested circuits are automatically discharged after testing 

Additional Features

Backlit Display: Available on MIT320 and MIT330 for use in dark environments 

Hands-Free Operation: Carefully balanced instrument can be hung around the neck 

Adjustable Buzzer Threshold: MIT320 and MIT330 allow adjustable continuity buzzer threshold from 1 Ω to 20 Ω 

Test Result Storage: MIT330 can store over 1000 test results with USB download capability 

Technical Specifications

Insulation Testing

Parameter MIT300 MIT310/310A/320/330

Test Voltages 250 V, 500 V DC 250 V, 500 V, 1000 V DC

Measuring Range 10 kΩ – 999 MΩ 10 kΩ – 999 MΩ

Short Circuit Current 1.5 mA nominal 1.5 mA nominal

Test Current on Load 1 mA at min. pass values 1 mA at min. pass values

Accuracy (at 20°C) ±3% ±2 digits (up to 10 MΩ)

±5% (10-100 MΩ)

±30% (up to full scale) Same as MIT300