What is isolation rating?
An isolator’s isolation rating (also called the test voltage) is a measure of the protection provided against short-duration, common-mode voltage differences. Usually specified in terms of a 60 Hz RMS value, it is a rating of how much voltage can be safely applied between the input and output terminals of the device for a duration of one minute. A common isolation rating found on isolation devices is 2.5KVRMS. Other devices have ratings such as 3.75KVRMS or higher. The isolation rating does not describe how much voltage can be safely applied across the part on an long-term continuous basis this is described by the “working voltage” or “rated mains voltage.
