All electrical insulation is susceptible to degradation over time. At the start of its service life, the insulation applied to an electrical system - whether it's a common appliance such as a kettle or a high-powered device like a transformer - should be strong enough to make leakage current non-existent or negligible and ensure that the electrical installation/appliance can be used safely.
However, insulation will degrade over time leading to more potential leakage current. As such the system becomes less and less safe over time, and this is exactly why insulation resistance tests must be regularly carried out to ensure that the resistance of the insulation is sufficiently high.
We have a range of different insulation testers depending upon the application they are to be used in.
