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Now, in the absence of any GFCI, what hazards could using a fake EGC (connected only to a ground rod connected) provide over a simple 2 wire circuit? For one thing, in the event of a hot to fake EGC fault, it increases the danger area from just the normally non-current carrying metal parts of the equipment to the earth around the ground rod. Maybe that's it, but I bet with some thought we could come up with other scenarios.The presence of the GFCI in an EVSE mitigates these hazards somewhat, because a 20,000 ohm connection should be sufficient to trip a GFCI at 120V, and earth electrode resistance is typically less than that. However, the cord of the EVSE is still not GFCI protected, so there is still some increased risk due to a fault in the cord from hot to fake EGC. If the EVSE is hanging by its maximum 18" cord, the strain put on the cord makes that a not-so-remote possibility.The upshot is that the EGC has very little to do with earth or with ground rods.Cheers, Wayne
Now, in the absence of any GFCI, what hazards could using a fake EGC (connected only to a ground rod connected) provide over a simple 2 wire circuit? For one thing, in the event of a hot to fake EGC fault, it increases the danger area from just the normally non-current carrying metal parts of the equipment to the earth around the ground rod. Maybe that's it, but I bet with some thought we could come up with other scenarios.
The presence of the GFCI in an EVSE mitigates these hazards somewhat, because a 20,000 ohm connection should be sufficient to trip a GFCI at 120V, and earth electrode resistance is typically less than that. However, the cord of the EVSE is still not GFCI protected, so there is still some increased risk due to a fault in the cord from hot to fake EGC. If the EVSE is hanging by its maximum 18" cord, the strain put on the cord makes that a not-so-remote possibility.
The upshot is that the EGC has very little to do with earth or with ground rods.
Cheers, Wayne
