"False" grounds on board, i.e. neutral wire and grounding wires connected at appliances or panel bus bars.
Swapped neutral scenarios in dual load groups.
Vessels equipped with auto-trip devices for reverse polarity.
Electronic "noise" issues from loads on the boat or dock.
VHF emissions in close proximity to the ELCI CT coils.
Green grounding conductor routed through the ELCI sensing (CT) coil.
Open in grounding circuit.
Depending in the specific ELCI, very sensitive to back feeding. They cannot be used as part of a source selector and may also be polarity sensitive.