Electrical Plan Drawing Software. They come with built-in templates which enable in the quick drawing of the electrical plan. SmartDraw – Free software for drawing electronics schematics.
Just place electrical symbols into the drawing and attach the wires. Maximum care was paid to ergonomics and ease of use. Electrical Drawing Software – Simple, Superior, Second to None.
IO is a free online UML tool.
You can also share any open source SCADA softwares (via comments) which are missed in the above list.
EdrawMax is an advanced all-in-one diagramming tool for creating professional flowcharts, org charts, mind maps, network diagrams, UML diagrams, floor plans, electrical diagrams, science illustrations, and more. Circuit drawing or electronic schematic drawing is not a hard to learn stuff, you can make it better with practice. Just place electrical symbols into the drawing and attach the wires.