High-voltage insulation test sets are essential tools for condition assessment of almost all major items of electrical power plant, including transformers, bushings, circuit breakers, cables and rotating machines. Many of the insulation test sets currently in use have significant shortcomings, which means not only that they are less convenient to use than they should be, but also that the results obtained are less comprehensive and less reliable. A new generation of instruments is now available which addresses these shortcomings.
To see what these versatile products have to offer, let’s take a look at one of the latest 12 kV insulation diagnostic systems. The first thing users are likely to notice is that it is much more portable than its older counterparts – its two-piece design weighs a total of 36 kg, making it probably the industry’s lightest power factor test set. Another useful benefit is provision for fully automatic tan delta/power factor and tip-up testing, which is a big time saver. Facilities are also available for manual testing – including the option to increase the test voltage during the test – to allow special testing requirements to be accommodated The ability of the test set to generate its own test voltage, which can be varied in frequency over the range 1 to 500 Hz not only increases its versatility, but also ensures that dependable and repeatable results are obtained even when the instrument is fed from a poor quality supply.