The contactors are screwed to a piece of wood screwed to the enclosure, they aren’t grounded yet.simply attach the ground wire to the enclosure,
the grounding of the contactors has already been accomplished by the screws that are retaining the contactors to the enclosure, .anything attached to the enclosure will be grounded
When the screws contact the base of the relay and the enclosure, and the ground wire is attached to the enclosure, ground has been achievedThe contactors are screwed to a piece of wood screwed to the enclosure, they aren’t grounded yet.