Typical Ground Fault Animation
In Figure Six, we illustrate how things work in a not so perfect world. Our good ship "Problem" has a problem. The toaster oven has a direct short to its case. In this scenario, the captain of the "Problem" plugs in his shorted toaster oven. Phase current at whatever level required by the circuit resistance and at a line voltage of 120 volts would flow from the marina's power source through the pedestal, shore power cable, distribution panel, 15 amp circuit breaker, to the branch circuit and grounding receptacle supporting the toaster oven. Phase current would flow from the marina's power source through the pedestal, shore power cable, distribution panel, 15 amp circuit breaker, to the branch circuit supporting the toaster oven. Because the toast oven has a short to its case on the phase side of the load, it offers no resistance to the 120 volts circuit. In fact, the heating elements of the toaster oven and the "neutral" ground wire are not even part of the circuit anymore. The "new" circuit utilizes the "green" safety wire as its return path to ground. Current would bypass the 14 ohms load placed on the circuit by the toaster oven and head directly to ground via the grounding receptacle's "green" wire connection to ground. Hopefully, the circuit breaker would trip disabling the circuit.