This article proposes the research and simulation of general bars of medium voltage metal enclosed switchgear, made of aluminum bars with copper contacts, in order to find a similar or even more convenient solution than that of copper bars, both from a technical and economic point of view. The goal is to improve heat distribution at the passage of the current, in the bar and particularly in contacts, under rated and under short-circuit. As a result of simulations under rated current, a uniform distribution of the temperature was achieved which does not exceed the required limits. Under short-circuit the distribution of the thermal field in the contact area revealed the fact that the obtained thermal values do not exceed the limits specified in the literature for the electrotechnical aluminum under short-circuit.