I was just wondering is all electrical high voltage lines including low voltage is isolated to prevent electrical shock.
Electrical wiring are insulated not only to protect you from electrocution, but to keep the currents to the destined directions and not go astray.
Some do and some don't ! High voltage power line that runs at 20000 volts to 50000 volts is a bare wire. Lower voltage street line from pole to pole (about 5000 volts) is also bare wire. After step down by the small street transformer then feed to the house 240 volts is insulated wire. All the AC wiring inside the house carries 120 volts and 240 volts is insulated wire. Most electronic circuit board has printed circuit which has hundreds of bare wire.
Wiring is normally insulated. If you have ever seen old wire with cracks in the insulation please know that it is not safe to use or handle and should be replaced or repaired. Be careful in handling any wire especially if it has current going through it. It could have a faulty spot and you could get a shock. It doesn't take much to crack the insulation or wear a bare spot on some wires. Usually if the insulation is hard or brittle the wire has been over heated and the insulation may not be very good. It may break off of the wire and expose the wire. Never touch the bare wires or exposed connections on a car battery. And be very careful not to touch bare electrical wires in general.
No. Electrical power lines are not insulated in a way to prevent shocks. They are coated to protect the cable from weather, but that coating is not adequate protection. Anything that is generally touchable should be insulated. There are many regulations and standards (like UL) that devices have to meet. However, damage, poor design, or a sloppy manufactured product could still have electrical hazards. It doesn't take much voltage to kill you, depending on the conditions (that's why water and electricity are such a bad combinationwhen things are wet, they conduct better, and it takes lower voltage to reach the death-threshold of a shock).
