I have a GFCI outlet that is in a garage which is feeding other outlets in the garage and also feeds two garage door openers.

When both doors are operated simultaneously the GFCI will trip off. If only one door at a time is operated then it is fine.

What would cause the GFCI to trip? I do not believe it is due to load or could it be? I thought a GFCI only tripped when it sensed a difference in the neutral current compared to the line current. The openers are Genie screw drive type openers that operate double wide doors. If that makes any difference.

Thanks

glenn35