Editing Appliance classes (section)

==Class II==
[[File:Double insulation symbol.svg|thumb|upright=0.5|Class II symbol]]

A Class II or '''double insulated''' [[electrical appliance]] uses reinforced protective insulation in addition to basic insulation. Hence, it has been designed in such a way that it does not require a safety connection to [[Ground (electricity)|electrical earth]] (ground). 

The basic requirement is that no single failure can result in dangerous [[voltage]] becoming exposed so that it might cause an [[electric shock]] and that this is achieved without relying on an earthed metal casing. This is usually achieved at least in part by having at least two layers of [[Electrical insulation|insulating]] material between live parts and the user, or by using reinforced insulation. 

In [[Europe]], a double insulated appliance must be labelled ''Class II'' or ''double insulated'' or bear the double insulation symbol: ⧈ (a square inside another square). As such, the appliance should not be connected to an earth conductor because the high-impedance casing will cause only low-fault currents that are unable to trigger the fusible cut-out.<ref name=ESDBook/> 

Insulated AC/DC power supplies (such as cell-phone chargers) are typically designated as Class II, meaning that the DC output wires are isolated from the AC input. The designation "Class II" should not be confused with the designation "Class 2", as the latter is unrelated to insulation (it originates from standard UL 1310, setting limits on maximum output voltage/current/power).