Your trees are your responsibility, and if you don’t keep them out of powerlines you could be fined up to $10,000. Trees close to power lines cause outages, especially in high winds. If you’re rural, this means you have no water either!
Clearance does depend on the voltage of the lines but for residential trees generally 1.5 meters clearance is required for 400v lines and 2.6 meters for 11,000v lines. You need to factor movement of the tree during strong winds and moisture retention in the canopy can lower it considerably with the weight of water on the foliage.
Pruning for good clearance is not for the DIY hero. Electrocution is serious stuff, so employ a qualified Arborist like The Treeman and be proactive. As a trusted contractor to Counties Power we have the skills to help you and we are local. Planning ahead is key. We are in enough crisis at the moment without losing power on a stormy night too.