TL;DR
An insulation resistance test is the megohmmeter measurement that applies a DC test voltage, commonly 500 or 1000 volts, between conductors and ground to verify that wire and equipment insulation still blocks leakage current, with healthy readings in the megohm range and above. Electricians run it on feeders after damage or flooding, on motors showing nuisance tripping, and solar installers test PV string wiring where a low reading reveals chafed conductors before they arc.
What it means
An insulation resistance test is the megohmmeter measurement that applies a DC test voltage, commonly 500 or 1000 volts, between conductors and ground to verify that wire and equipment insulation still blocks leakage current, with healthy readings in the megohm range and above. Electricians run it on feeders after damage or flooding, on motors showing nuisance tripping, and solar installers test PV string wiring where a low reading reveals chafed conductors before they arc. It finds degradation that a continuity tester cannot see.
Where it sits in the glossary
Insulation resistance test is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
License: CC-BY-4.0 — quote freely with attribution to ProFix Editorial Team / ProFix Directory.