I would like to build a sous-vide circularor, using a PID-controlled immersion heater. I've read that as the product wears out, there might be some electricity leakages, so I would like to make the apparatus safer.
Here is what I thought about:
Two electric wires are submerged together with the water heater, and connected to one side of a normally closed relay. When there is electricity leakage, the relay commutes the switch on the other side, killing the power to the heater.
Would this work? Do you have a better way of making the device safe(r)?
Finally, what should be the specs of the relay I should buy? I really don't have a clue of what voltage would flow in, say, tap water, during a leakage. Thank you in advance, please take into account when answering that I'm a complete electricity-amateur.
Edit: the power supply are L+N