Metrel MI 3288 Earth Insulation Tester with 2 A Micro-ohm

Earth, insulation and micro-ohm testing in one battery-powered instrument

The Metrel MI 3288 Earth Insulation Tester is a portable, battery-powered instrument with IP54 protection, designed for high altitude (300 V CAT III at 4000 m). It measures earth resistance, specific earth resistance, earth potential, step and touch voltages, insulation resistance and continuity of protection conductors on energy and non-energy objects.

For earthing it offers 2-, 3- and 4-pole earth resistance, a selective 4-wire method with one clamp, a two-clamp stakeless method and 4-wire specific earth resistance by the Wenner and Schlumberger methods. A multi-frequency test signal (20 or 40 V AC) gives noise immunity, and 55 Hz is also supported. For insulation it tests from 50 V to 2500 V with a range to 100 GOhm using the guard terminal, with PI, DAR and DD calculations, a varistor test to 2.5 kV and a DC withstand test up to 2.5 kV. A micro-ohm function with DC test currents of 10 mA, 100 mA, 1 A and 2 A, in single, continuous or inductive mode, covers contact and winding resistance, and continuity can be measured at 200 mA or 7 mA.

Results are shown on a 4.3 inch colour touch screen, can be limited with programmable Hi/Lo limits, and are stored for transfer by Bluetooth or USB to the Metrel ES Manager software.

Technical specifications

Applications and set contents

Metrel lists initial and periodic testing of domestic and industrial installations, TT and IT systems, lightning system testing, industrial areas, smaller buildings and mining installations, substation earthing, motor and generator windings, power transformers and inductors, wire and cable resistance, and insulation resistance of transformers, motors, cables and machines.

The standard set contains the instrument, a 7.2 V 4400 mAh battery pack, a 12 V / 3 A power adapter, a 2.5 kV test lead, a green 1.5 m lead and a four-lead set, test probes and crocodile clips, a soft carrying bag and neck belt, USB cable, a Metrel ES Manager BASIC licence, manuals and a calibration certificate. Further versions add earth test sets of 20 m and 50 m lead length, as listed in the leaflet.

What to confirm before ordering

Choose the set by earth lead length (standard, 20 m or 50 m earth test set) and decide whether clamps are needed for selective or stakeless measurements. Confirm the insulation voltage your procedure requires: 2.5 kV is the maximum. Also state whether the micro-ohm current of 2 A is enough for the contacts or windings you check, and whether the software licence and calibration certificate are required. Specifications are subject to change without notice.

Documents and quotation

The Metrel leaflet is attached as a datasheet. For another earth tester see the Megger DET4T2 four-terminal earth ground resistance tester, and for micro-ohm testing the Megger DLRO10X 10 A digital low resistance ohmmeter; the full list is in the portable test and measurement category. Send the set, options and quantity for a quotation.