Why is the water inside the kettle not electrified?
In: Physics
The electricity never goes into the water itself, it just feeds into a heating part. The heat transfers through the kettle into the water. Sort of like if you have an oven, the electricity goes through the “wall” of the oven and heats the air up. But you won’t get electrocuted if you touch the rack inside that the food sits on because that rack doesn’t actually touch the electrified portion of the oven.
Water doesn’t conduct electricity as well as the metal coil does, so the electricity exits the metal coil instead of into the water.
House fires used to be caused from short circuits because the short circuit would draw more current then the wire in the walls was capable of handling which caused the wire in the walls to get so hot it would melt its insulation and light off anything flammable.
So now we use circuit breakers to stop wires from carrying too much electricity but we figured out that we can purposefully overload wires or any conductive metal surface like it with electricity to generate heat and we can encase those wires in ceramic or some heat resistant insulation to have a non conductive heating element that we can easily control by the amount of electricity we let flow through.
So the heating element in your water could just be the shortest path to ground, when you electrolyze water you usually have two electrodes in the water forcing the electricity to jump from one to the other through the water. With a heating element its usually one long large heating wire maybe coiled up a bit but all one piece so no reason to jump from one part to the next through the more resistive water.
The heating element is usually insulated from the electricity in a kettle.
[Here’s a video of a water heating element](https://youtu.be/JkNdM3TRZs4) being cut open. It consists of the heating wire, some insulation powder and then the outside metal tube.
There are some countries that use non-insulated heating elements to heat water, such as in [this shower head video](https://youtu.be/cNjA0aee07k?t=318)
And some countries use devices that use the water to conduct electricity between live and neutral terminals, such as in [this water heater video](https://youtu.be/EViyccc2t9w?t=206). The water has high resistance, so the electricity heats the water as it passes between the electrodes.
In an electric water heater, the electricity wants to flow from the “hot” wire into the “ground” wire. A properly wired heating element provides an easier way for the electricity to get to ground than by flowing through the water itself. If the heating element is not designed correctly, then the electricity may not always have a better path, and these elements can cause lethal shocks. This is why there are strict laws about the design and use of electrical heating elements in or near water.
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