This is the reason one should never go away from your mining basement for too long, wires can melt, plugs can melt and start a fire at any time especially if you are drawing up to 1000 watts to your mining rigs, it's better to stay around at home when mining and if it's a most to leave do not go too far away
I had no issue for 3 years. Only when I reconnected everything I made a mistake and connected 3 farms on the same plug (I have two 10A plugs)