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by BJBBB 3505 days ago
Need to correct some stuff.

Class 2 (arabic numeral) is for limited power sources, regardless of construction class.

Class II (roman numeral) indicates a construction class where safety cannot be dependent on a ground bond.

Class I (roman numeral) indicates safety is dependent on a reliable ground bound.

Class I equipment, depending on the scoped end-use equipment safety standard, can have up to 25mA of leakage.

Class II equipment, depending on the end-use environment, can be limited to 0.25mA of available touch leakage.

A good reference for Class 2 and 3 equipment is the UL5085-x series (same as CSA No66.x).

For the EU, there are no harmonized standards in the Low Voltage Directive that have an equivalent Class 2/3 construction, although there are several safety standards that address requirements for 'inherently limited' power sources.