Adds a selection tool which can be used to separate one part of your factory to explicit electric network. You just draw a rectangle frame with this selector and any copper cables crossing this frame will be removed. Doesn't affect red or green. Doesn't affect copper cable connections to switch entity.

Why:
If you want to turn of some parts of your factory with Power Switch you'll find it annoying that you can't just cut all thouse connections.

Additionally:
Alt mode will remove red and green connections.

Also there is a hotkey (see Controls/mods) with witch you can lock on a specific electric network. Press this key while you hover over a pole. When you do, new poles build near old ones will only connect to the locked network.

This should allow you to build an isolated power line crossing all your base and it won't connect to other electric networks.