Symbol 6300 from IEC 60417 - Title/Meaning: Suitable for uninsulated hazardous live conductors Function/description: To indicate that the current sensor can safely be used with uninsulated hazardous live conductors.
Additional information: 
The square with a bold-rim implies “safe” as defined in [IEC 60073 Ed.6] (2002), which has the status of a basic safety publication in accordance with [IEC Guide 104].
For technical detail, see [IEC 61010-2-032 Ed.3] (2012-09) .
[;2015-07-31: 3C/2115/CDV;2015-11-22: 3C/2154/RVC;2016-02-05: 3C/2157/FDIS;2016-03-25: 3C/2167/RVD;]
Own work using: iso.org/obp/graphics/grs/57341ab8-7034-40dc-b0dc-1049aff46648 200.png
Vectorization:  Mrmw