Turning A Fermenter Into A HLT. ?

[Greg2013]

This might be a stupid question but ye know me by now i will ask anyway  : Ok so this week i am going to be converting a 33 litre bucket FV i got from HBC(thank you btw) into a HLT,i will be using two argos kettle elements. Do i need to earth these in the same manner as if installing them on a keg or does it matter at all given that it is a plastic bucket and thus non conductive ?

https://www.thehomebrewcompany.ie/33-litre-fermentation-vessel-graduated-p-1986.html