Interpreting long-term insulation resistance trends
Having good insulation on electrical equipment is rather like having a water tank in your loft that’s actually watertight. In both cases, the cost of repairing an actual fault – whether it’s poor insulation or a leaking tank – is likely to be much less than the cost of repairing the damage caused by the fault. Nevertheless, how many people actually take the trouble to look occasionally at their water tanks to check that they are in good order? Not many, I suspect, even though doing so could potentially save a lot of money and heart-ache.