My brew rig is on wheels, therefore isolated even further from Mother Earth. I am about to add a circuit to control (manual on/off) my recirculation pump and chiller water pump. As you can see in the circuit diagram, it is a simple switched outlet pair. The recirculation pump is bolted directly to the frame. The other pump is a submersible pool pump that is grounded via it's power cord, and when in use is in the swimming pool. The switch and outlet boxes are plastic. Right now I do not have any other electrical components on this brew rig. So - I plan to tie the rig input power cord ground directly to the rig frame with a metal to metal connection. Here is a picture of my brew rig, without the pump switches and outlets installed yet. Any suggestions or issues that you guys see with this? Thanks in advance, and cheers!