newbie earth bonding

[dave_k]

Hi all
this is my first post so quite new here and to the refrigeration trade. I an working as aengineers mate on refrigeration installs. I have just passed my 17th edition but have yet to gain a lot of experian within the trade. ok my question?
I recently assisted installing a large walk in freezer to which i did the wiring with some guidance from the engineers. Now on the evapourater drain is a heater coil which wraps around the copper pipe which is connecteds to the evap drain by a plastic fitting then the pipe runs outside to the drain. In my opinion this drain shoud be bonded as the only earth conetion under fault conditions would be human contact.
cheers
Dave