My DR4018s run off my 12v d.c. bus which is supplied from an industrial 5A regulated power supply. It also supplies structure lighting and other 12v electronics, the DR4018 supplies signal heads and relays that operate slow motion switch machines, but not direct to switch machines.
For wire size and solenoid motors more important is that the resistance is low enough to allow enough current to flow to operate the motors. A close motor can use smaller wire than a farther one. The rating is not so important because the wire is only under load for a fraction of a second at a time.
Mike Ruby
