Since an aircraft plug may max. transfer 90 kVA, GPUs with ratings from 120-180 kVA are normally supplied with two output contactors each of them designed for 90 kVA. If the GPU is not going to supply an aircraft, but to supply a distribution board or to be used in a parallel configuration, the two outlets of the GPU can be connected in parallel to one single outlet. The single outlet can then, of course, deliver the full GPU power.

Also, the controls can be connected in parallel and the arising single outlet can, afterwards be operated by the controls of both contactors