What is the current capacity of this cable?
Assuming the resistance is 300% of the resistance of 1.5 mm^2 wire and the thermal cooling area is only 57%, you can keep it cool enough if one wire has max 2 amperes RMS continuously in free air. Four wires in parallel can handle 8 A.

But that's not all! How long is your cable? Do the fuses trip in case of a short circuit soon enough (=before there's a fire)? There's length limitations is regulations also for that reason. What wires are before your cable affects too!

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