Table B: Basic and Reinforced Isolation Requirements
Common differences between basic and reinforced isolation requirements for various standards.
See specific standard for your system as requirements may vary slightly.
Safety Extra-Low-Voltage—A voltage less than 30 VRMS (60 VDC)
Hazardous—A voltage greater than 30 VRMS (60 VDC)
Basic Insulation—A single-level of protection against electric shock.
See Table B.
Reinforced/Double Insulation—Two-levels of protection against electric shock.
See Table B.
Rated (Proof) Isolation Voltage—The maximum voltage an isolation barrier is rated to withstand. This is typically 2500, 3750, or 5000 VRMS for 1 minute.
Production Isolation Test Voltage—The voltage to which an isolation component manufacturer must test the component in order to be compliant with a given standard. This test voltage is typically 1.2x the Rated Isolation Voltage for a test duration of 1 second. Each standard has slightly different test voltage requirements. The most strenuous and inclusive requirement is chosen for this test.
Time-Dependent Dielectric Breakdown—The amount of time it takes a component's isolation barrier to fail for a given voltage. In general, the lower the voltage, the exponentially longer the time a safety component can survive.