For what it's worth, this Wikipedia article says it's good for .577 A per conductor and 125VDC. Seems there are 8 conductors per wire so that gives you under 5A per wire; your 7A is asking for trouble.
I'm not able to comment on the VDC vs VAC thing....
But I'll go with lefty (as usual 8) ) and others on this: don't mess with stuff like this when you don't understand it. It's not worth the risk.
Have to ask: why are you asking?- you have lots of surplus wire?