Is here no markings on the cable ?
could it be like this Black Tri-rated Cable, 0.5 mm² CSA, 1 kV dc, 600 V ac
https://uk.rs-online.com/web/p/tri-rated-cable/1805910/
John
PS
or may be Farnell in US
https://www.newark.com/w/c/cable-wir...0ac%20%20cable