🔍 Key Concepts

• Megohmmeter operation – it applies a high DC voltage and measures insulation resistance over a short period of time • Insulation as a capacitor – at first the insulation charges, then the reading should stabilize if the insulation is good • Difference between stable high resistance vs. erratic or falling readings that suggest leakage

💭 Think About

• When you first connect a megohmmeter to a dry, healthy insulation system, what happens to the pointer as the insulation charges and then reaches steady state? • Which option best describes a reading that settles at a high resistance value instead of continuing to drop or fluctuate? • If the insulation were damp or deteriorated, how would the pointer likely behave differently over time?

✅ Before You Answer

• Make sure the correct choice describes a high resistance reading that stabilizes, not one that keeps dropping • Check which option shows a temporary change followed by a steady, reliable indication of resistance • Eliminate any option that suggests continuous dips, kicks, or instability rather than a stable final value