One topic in school science was electricity. My two girls have both had this subject in elementary school over the last few years. Both have come home with various projects involving batteries, wires and the construction of a basic circuit. Dad was like a kid in a hardware store.
What is taught to the children is that electricity needs conductors in order to flow and create a circuit. The other part of this lesson is insulators. Electricity can not flow through insulators, only conductors. The kids easily grasp this concept and have fun making circuits.
Some where along the way to adulthood I theorize, these basic concepts of electricity are washed from the child's brain. Perhaps it puberty, the raging hormones send the brains focus elsewhere. Whatever the reason I find adults who have clearly forgotten the very basics of electricity.
Let me share a recent example. Here we have a whole house water filter. There are actually two lessons here, but I will stick to the topic. The housing of the filter is plastic. As we all know plastic is an insulator, it does not conduct electricity. Wires are coated in plastic.
The copper pipe is metal. Metal is a conductor. In fact copper is a great conductor of electricity. Wire is made from copper. Like this grounding wire clamped to the copper pipe in the second picture. That wire is actually a bonding wire for this house's water supply piping. This wire is not the main grounding conduct for the electrical system. It is a secondary grounding conductor for the copper piping in the house. In the event the copper pipe was to become energized, this wire would provide a path to ground.
Think of this, somehow electricity has come in contact with the water supply pipes in your house. The pipes are now energized. You get up in the morning, go to the sink, touch the faucet handle and you get walloped. I assure you that'll wake you up faster than a cup of espresso.
With the wire on the pipe, electricity has a path to ground. You will definitely still get a shock with the wire in place, but it will be greatly minimized.
Getting back to that water filter. The installer failed to take into account that once the filter was put in place, the path to ground was broken by the plastic filter housing. Repair will involve either moving the grounding wire or installing a jumper wire.
So easy even a kid could do it.