Megger MIT330 MIT Series Insulation Resistance Testers

Megger MIT330 is a high-performance insulation and continuity tester from the MIT300 Series, designed for electrical contractors and maintenance professionals working in domestic, commercial, and industrial environments. This rugged, battery-operated instrument combines insulation testing up to 1000 V with fast continuity testing and advanced data management capabilities.

The MIT330 features a dual digital/analogue display with large 20mm high characters and an analogue arc that provides the "feel" of a traditional analogue instrument while delivering the precision of digital readout. Its intelligent safety system and rugged rubber armored case make it ideal for harsh field conditions.

Key Features at a Glance

Feature Specification

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

Insulation Resistance Range 10 kΩ to 999 MΩ

Continuity Range 0.01 Ω to 1 MΩ (MIT320/330 only)

Voltage Measurement 0–600 V AC/TRMS

Display Type Digital LCD with backlit analogue arc

Data Storage Up to 1000 test results

Data Download USB interface

IP Rating IP54 (dust and water resistant)

Operating Temperature -10°C to +60°C

Dimensions (HxWxD) 148 mm x 203 mm x 78 mm

Weight 980 g (instrument only)

Power Supply 8 x AA batteries (alkaline or NiMH rechargeable)

Safety Rating CAT IV 300 V / CAT III 600 V

Warranty 3 years

Detailed Technical Specifications

Insulation Testing

Parameter Value

Test Voltages (Fixed) 250 V, 500 V, 1000 V DC

Measurement Range 10 kΩ to 999 MΩ

Accuracy (at 20°C) ±3% ±2 digits up to 10 MΩ; ±5% up to 100 MΩ; ±30% up to full scale

Short Circuit Current 2 mA (nominal)

Test Current 1 mA at minimum pass values

Automatic Discharge Yes – discharges capacitive circuits after testing

Continuity Testing

Parameter Value

Measurement Range 0.01 Ω to 1 MΩ

Open Circuit Voltage 5 V ±1 V

Short Circuit Current 205 mA +10 mA / -5 mA

Accuracy ±3% ±2 digits (0–100 Ω); ±5% ±2 digits (100 Ω–500 kΩ)

Lead Null Up to 10 Ω

Voltage Measurement

Parameter Value

Measurement Range 0–600 V AC (50/60 Hz) or DC

Accuracy DC or AC: ±1% ±2 digits

Default Voltmeter Activates automatically when >25 V AC/DC is detected

Live Circuit Warning Yes – audible and visual indication

Test Inhibit Testing inhibited if >50 V detected