Fake electrical cables from China

My Daikin aircon at work is now functioning. It wasn't for a week. The Daikin repairman was clueless. My mother called her usual aircon man over. He was experienced and he found that the copper wires were fakes from China. The wires were aluminium with a coloured coating made to resemble copper. Upon burning, it gave off a white ash. I looked at the cross-section of the fake cable and saw silver rather than the ochre copper colour. After reconnecting with real copper wires and everything is fine.