To ensure personnel’s health and safety, the converter is equipped with an interlock system. The configuration of the interlock system depends on whether the GPU is going to supply a civil or a military aircraft. In case of a civil aircraft, the aircraft supplies the 28 VDC interlock voltage, but in case of a military aircraft, the converter generates the interlock voltage.

The military interlock system is designed as a separate 2 A supply as shown at figure 1 below. Kindly notice that the E terminals are prefused with 2 A per outlet.

                                                           Fig. 1: Military Interlock

Change over between the civil and the military interlock system is done by means of the selector switch S30 that is placed behind the front door.

The civil interlock system is designed as shown at figure 2 below