GolfR
Well-known member
The ground fault protection is looking for a short from the ground to any other leg of circuit. Much like what would happen in your bathroom, if either leg (hot or neutral) are shorted to ground by hitting your sink full of water, it will immediately disconnect the power. In the instance of hooking the truck into a house circuit, the house has ground and neutral shorted together at the breaker box so it trips the truck's ground fault protection. This works exactly as designed. The truck generator is likely designed this way because it's a completely floating generator system. The only ground for the truck itself is through the connections you make or you touching the door handle with your feet on the ground. The rubber tires are very good insulators.Thanks for this, Golfr - just to be clear (I deal with 12V all the time but AC is a bit ofa mystery to me): if the neutral is grounded on the truck-side of the 30A connector, then why would connecting the ground wire to the grounded neutral be different from connecting it to truck ground?
Put another way: If I connect an ohm meter from grounded neutral to ground on the truck’s 30A receptacle, what would it read? Thanks again for your help.
The "danger" of using a non-bonded neutral/ground generator (Not the F150 system) with the cable described above is that the chassis ground (metal frame) would be completely floating. The only ground would be through the chassis to the pavement or cement it's sitting on which can be a terrible conductor. If the chassis ground floats or builds up voltage because there is no path to ground, a user could touch the chassis and short the potential energy to ground through their body. It would basically be like hitting yourself with a defibulator as the ground float could potentially be 100s of volts.
To the second question, the neutral and ground pins in the truck are bonded inside the truck so the potential difference (voltage) between the two is zero but because of the fault circuitry, there should be some measurable resistance. It will not be zero. The fault circuitry looks for a voltage drop over that resistance between the neutral and ground legs which only occurs if there is a current through that fault circuitry resistance. At least this is one way to do it, I don't know exactly how the truck is wired up.
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