ET online
July 2008
CAT IV for the 5 and 10 kV testers

CAT IV for the 5 and 10 kV testers

01 July 2008

Paul Swinerd - Product manager

One of the most valuable predictive and diagnostic tests for many types of equipment, including motors and generators, is high voltage insulation testing. There are many test sets on the market for this type of testing, but they are by no means all created equal.

For example, the latest 5 kV and 10 kV insulation testers in the Megger range fully meet the requirements for use in CAT IV 600V applications, in line with IEC 61010-1. This means that they provide enhanced safety by offering immunity to transients up to 8kV – double the rating of their predecessors.

An equally important benefit is that, uniquely for instruments of this class, Megger fully specifies the performance of the guard terminal. This shows that, unlike many of its competitors, Megger has achieved important safety enhancements without in any way compromising guard terminal performance.

As a result of the well-defined performance of the guard terminal, combined with the high current capability of the testers, users can be sure of achieving fast, accurate results even in the presence of high levels of surface leakage in the equipment under test. This is important as it enhances the ability of the instrument to provide reliable information to assist in the diagnosis of faults.

Megger has also upgraded the software supplied with the instruments to the latest PowerDB Lite package. This allows test results to be loaded directly into test forms and certificates that are uniform in layout and appearance with the test documentation produced by many of the other power instruments in the Megger range.

Megger high-voltage insulation testers offering CATIV 600 V capability are the MIT510/2 5 kV insulation tester, the MIT520/2 5 kV diagnostic insulation tester and the MIT1020/2 10 kV diagnostic insulation tester, along with their high-current S1-range counterparts, which deliver a test current of up to 5mA compared with 2mA for products in the MIT range.

The CATIV 600V rating also applies to the S1-554/2 5kV and S1-1054/2 10kV high noise immunity testers, which are particularly well suited for use in substation switch yards and other areas where extremely high levels of electrical noise may be present.

To complement the new versions of its insulation testers, Megger is now supplying them, as standard, with insulated test leads rated at 5 kV or 10 kV depending on the type of instrument. Compact uninsulated crocodile-clip style leads continue to be available as an option.