Metrel MI 3201 TeraOhm 5 kV Plus High Voltage Insulation Tester

A 5 kV insulation tester with diagnostic tests and a live R(t) graph

The Metrel MI 3201 TeraOhm 5 kV Plus is a portable instrument for measuring insulation resistance with DC test voltages up to 5 kV. It measures up to 10 TOhm, and adds the tests that maintenance engineers use to judge insulation condition rather than just read a single number: step voltage, withstanding voltage, polarization index (PI), dielectric absorption ratio (DAR), dielectric discharge (DD) and capacitance measurement.

A large LCD plots resistance against time in real time, so the response of the insulation to the applied voltage is visible during the test. The test voltage is selectable from 250 V to 5000 V in 25 V steps, a programmable timer runs from 1 s to 100 min, and a guard terminal removes the effect of surface leakage. A 5 mA current source charges capacitive loads quickly, selectable noise rejection filters and shielded leads support accurate results, and the tested object is discharged automatically after the measurement. Results are stored and can be downloaded over USB with the optional HVLink PRO software.

Technical specifications

Applications and standard set

Metrel lists insulation resistance testing of rotating machinery, cables, transformers, high-voltage generators and surge arresters, periodic testing and maintenance on production lines, and troubleshooting and diagnostic analysis of all kinds of insulation problems. The programmable step voltage and withstanding voltage functions help in fault finding, while PI, DD and DAR calculations are produced automatically with automated resistance ranging, and all the data are displayed during one measurement.

The standard set MI 3201 contains the instrument, a small soft carrying bag, a mains cable, two 2 m 10 kV shielded test leads with probes (black and red), two 10 kV crocodile clips, a 2 m green guard lead and crocodile clip, six type C NiMH batteries, a calibration certificate and the instruction manual. Longer shielded 10 kV leads up to 15 m, test tips, a 5 kV calibration box, insulation test plates and a carrying bag are available as options.

What to confirm before ordering

Confirm the highest test voltage required by your procedure: this model stops at 5 kV, and a 10 kV class instrument such as the Metrel TeraOhmHP 10 kV or the Megger MIT1025/2 is needed above that. Also confirm lead length for the object under test, whether the PC software is needed, and the calibration documentation you require with the instrument. Metrel states that photographs may differ slightly from delivered instruments and that specifications may change without notice.

Documents and quotation

The Metrel leaflet is attached as a datasheet. For other test instruments see the portable test and measurement category, and for a 10 kV alternative see the Megger MIT1025/2 10 kV insulation resistance tester. Send model, leads, options and quantity for a quotation from Seven Star LLC.