Symbol 0851 from ISO 7000 - Title/Meaning: Cool time Function/description: To identify the device on resistance welding equipment by which marking the control unit with the cool time is possible.
Additional information: 
The cool time corresponds to a time during which the current does not flow, hence the position of the reference identifying this symbol.
Own work using: iso.org/obp/graphics/grs/1cd92654-7391-4647-b28c-4b53f53bd9e5 200.png
Vectorization:  Mrmw