Field glossary

CAT rating

IEC category for transient overvoltage withstand; CAT III is a common HVAC floor, CAT IV for service-entrance work

Used across 2 Anvilfield field guides, most in HVAC.

Also defined as

Electrical: IEC 61010 overvoltage category (II, III, IV) for where a meter is safe to use, paired with a voltage

Where this shows up