Well the first thing you should consult is the electrical code for your region - that should be your bare minimum.
Type and level of interference depends on several things:
- Are either or both runs in conduit? That will add extra shielding.
- Are the runs parallel, crossing, or...? The longer they run parallel, the more induced current you'll get. If the coax lines are crossing the AC line, you're probably fine with little or no separation (PROBABLY - I have seen exceptions).
- How much current will the 220V line be carrying? This is probably the biggest factor: if there's no load on the line, there's no EM field around it, and thus no interference. As the current goes up, so does the size and strength of the field surrounding it.
Matt is correct, you will need to consult your local code. NEC 800.133(A)(2) states that Communications wires and cables shall be separated by at least 50mm (2 in.) from conductors of any electrical light, power, Class 1 non-power-limited fire alarm or medium-power network-powered broadband communications circuits. Exceptions are if separate raceways or conduit are used for separating the communications cables/wires from the power conductors.
.....and that code only deals with electrical safety, not interference of signal.
Most of it depends on your national cabling codes of practice and low voltage to extra low voltage cables.
Here in Australia, this would fall under AS/CA s2009:2013.
For us & for the rest of the world it's probably similar, 50mm between cables and 150mm between termination points. 0mm if there is a durable barrier between them.
However the recommendation is 150mm separation at all times.