The way I understand this system ... not "high load currents" ... especially considering cat 5 cable is used ... I do believe they (the code) are referring to the old 12 volt 50 watt lighting which turned out in many cases to be a fire hazard waiting to happen ... I recall a few dodgey installations where qualified sparkies had used 1.5 mm twin+e to wire from big wire wound transfomers in domestic and commercial applications.