The polarity reversal protection unit comprises a pyrotechnic separation unit, a detector unit, a trigger element, a first connection element that is electrically connected to at least one consumer connection and a second connection element that electrically connects a supply supporting structure to the first connection element. The pyrotechnic separation unit is located on at least one of the connection elements. The trigger element has a first connection to the detector unit, said connection being electrically insulated from the connection elements and a second connection to one of the connection elements in such a way that a current flux in the trigger element causes the firing of the pyrotechnic separation unit, causing the electrical separation of the first and second connection elements.