Specific features of short circuit in automobile electrical system

It is shown that fires on vehicles refer to particularly severe accidents, so the problem of increasing their fire safety is extremely important. It is experimentally illustrated that in a number of cases, when a short circuit happens in an electrical circuit containing 51AH/280Aand 60AH/330A batteries, a spherical fusion is not formed in a copper conductor with a cross-section of 0.75 mm^, but there is a burnout of separate conductor wires, their adhesion to the steel surface and destruction in the immediate vicinity of the contact point. The results of a study with JSM-6390LV scanning electron microscope of copper multiwire conductors samples and steel band exposed to short circuits at a voltage of 12 and 24 V are given. There are shown photographs of the copper multiwire conductors' fused surfaces, as well as of the steel band exposed to short circuits. Characteristic diagnostic factors are found out that allow to identify the cause of the damage in the event of a fire (high-temperature exposure, short circuit, current overload) of a copper conductor in an electrical circuit with a voltage of 12 V using the method of scanning microscopy. It is found out that the detected factors are stable and are not prone to changes in the natural storage conditions of a vehicle, which was damaged as a result of thermal exposure.

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