Electrical Ground Loops in Heavy Trucks

The number of electrical/electronic devices in heavy-duty vehicles are increasing rapidly. Many of these devices require a "clean" source of power, which may theoretically be supplied by a separate ground. Currently, tractors operate on one of three grounding methods, the frame ground being the most common. However, the introduction of a separate ground into the trailer could lead to serious ground loop problems with potentially dire consequences: electrical fires, ruined equipment, property damage, driver and public safety. The overall effects associated with separate grounds in tractor/trailer(s) vehicles is not completely known at this time. The research effort will examine the three existing tractor and proposed trailer methods. Different electrical/electronic circuits will be tested, analyzed, and evaluated to determine the impact of current load on electronic subsystems. Several devices which could potentially provide "clean" power and ground will be applied to trailers for testing and evaluation purposes. The successful completion of Phase I will provide solutions to the ground loop problem, establishing guidelines to be used by the heavy-duty truck industry and the government to set standards. Expected results also include the development of a device which would manage electrical circuits and provide a "clean" environment for electronic subsystems.