Reducing the risk of an electric shock by earthing a circuit

[gonadgranny]

Hi there. I would like to ask for some advice on the matter of reducing the risk of an electric shock by grounding the circuit. I have included an image to illustrate what I mean.
I have purchased some insulated heating elements which i intend to submerge into a water bath. i thought that by grounding the metal container so that if the insulation fails the current will pass through the water, short circuit the system and blow the fuse.
is this a valid safety measure?
any help on the matter would be very much appreciated. thanks.

 

[FvM]

To achieve a reasonable safety level, you'll use a RCD (residual current device). The ground fault current will be likely too low to blow a fuse but still dangerous.

 

[Audioguru]

Pure water is an insulator. Water with minerals or salt conducts enough to kill you but not enough to blow a fuse.
Most countries require a Ground Fault Interrupter that trips when it detects a low leakage current that will not kill you.
On another website there was a photo of the remains of a gentleman who used a do-it-yourself heater like that for his bath. They found his remains after he was cooking in the bath for weeks. Maybe he got electrocuted then the heater kept on heating.

 

[chuckey]

Yes!, earth the actual heater casing, this way any fault will draw enough current to clear the fuse.
Frank

 

[Audioguru]

Yes!, earth the actual heater casing, this way any fault will draw enough current to clear the fuse.
Frank

Only if the voltage is extremely high or if the water is extremely salty or acidic.

 

[FvM]

Only if the voltage is extremely high or if the water is extremely salty or acidic.

I guess, chuckey referred to a metal case of the heater itself. But an isolated heater doesn't necessarily have a metal case, e.g. a heater in glass envelope used for aquariums or chemical processes.

 

[gonadgranny]

Thanks for all the reply's. The heating element is metal and has been insulated with plastic. Are you saying that earthing the actual metallic heating element would be a safe option? Thanks.

 

[FvM]

Are you saying that earthing the actual metallic heating element would be a safe option?

Yes. That's the preferred option. You might still want a RCD, to handle e.g. cable insulation faults.