Tag Archives: IR testing

Dielectric Absorption Ratio (DAR) Explained: The 60-Second Insulation Diagnostic

You don’t always have 10 minutes for a full polarization index test. Sometimes you need a quick answer: is this insulation healthy or not? That’s where the dielectric absorption ratio comes in. The DAR gives you a meaningful diagnostic in just 60 seconds. It’s not as thorough as the PI, but it’s far more useful than a simple… Read More: Dielectric Absorption Ratio (DAR) Explained: The 60-Second Insulation Diagnostic »

How to Read Megger Test Results: Good, Bad, and Marginal

Three numbers come off an insulation test: the spot reading, the ratio, and the trend. Most people look at the first one and stop. The spot reading is the weakest of the three. It swings with temperature and surface moisture and tells you almost nothing about the winding underneath. The ratio — DAR or PI — filters most… Read More: How to Read Megger Test Results: Good, Bad, and Marginal »

Insulation Resistance Testing: The Complete Guide

Every wire, motor, transformer, and cable in your facility is wrapped in insulation. That insulation is the only thing standing between normal operation and a ground fault, a fire, or a serious injury. Insulation resistance testing tells you if that barrier is still doing its job. It’s simple, non-destructive, and takes minutes. Yet it’s one of the most… Read More: Insulation Resistance Testing: The Complete Guide »