Electrical components commonly affected by poor insulation are overhead cables. These cables are usually exposed to environmental factors that gradually degrade the insulation and reduce its efficiency. This results in decreased insulation resistance and sometimes water treeing. If neglected, its efficiency to carry current can be reduced to the point that it introduces large power losses in the system. There’s also a chance of causing electrical shocks to maintenance personnel.
If you are planning to invest in insulation testers, you might want to check out tools from Metrel testinstruments. One popular model is the 3200 10-kilo-volt insulation tester. It features an automated system that calculates dielectric absorption ratio, polarization index and dielectric discharge results. This simplifies testing and saves you time. It also has a safety feature of discharging the test sample especially long cable installations with high capacitance after each test. This prevents stored charges on the test sample which might electrocute the technician.