Symbol 5179 from IEC 60417 - Title/Meaning: Test voltage Function/description: To identify equipment which can withstand a test voltage of 500 V.
Additional information: 
Other values of test voltage may be indicated in accordance with relevant IEC standards: see for example IEC 60414
IEC 60414 was withdrawn and replaced by IEC 61010-1 Ed.3 (2010)
Published in: Supplement F, 1982
Own work using: iso.org/obp/graphics/grs/d38578f5-3fde-4146-a843-9c0fa9cbfbd5 200.png
Vectorization:  Mrmw