Originally Posted by
tabetha
You'd actually be worried about "protecting" a earth wire, is this in case it touches the body somewhere!!
The slight amount of resistance will not make any difference to the pump but a bad connection due to rust etc can.
The body will still show a resistance, especially as at the ends of thebodt there is a terminal where the wire is connected to it.
tabetha
The series resistance of 4 or 5m of anything less than 4guage cable is going to be enough at 20A to see a drop of at least 2/3 volts at the pump.
The series resistance through a massive cross-section of steel and a short cable at each end would be significantly less so long as proper connections were made i.e. 'star'/gripper washers + nylocks/spring washers; and would also be significantly cheaper.
Protecting the cable not to prevent shorts but to ensure that the earth is reliable. Don't be cocky.
Chris