It is a remote controlled source changeover system for Compact NSX 100/160/250 devices. It is composed of an ACP plate and of an electrical interlocking system. This ACP provides in a single unit the protection of the controller, the control and the connection to the devices. The electrical interlocking is implemented by the IVE unit integrating control circuits and a external terminal block. The integrated control circuits implement the time delays required for correct source transfer. The control voltage is from 48VAC to 415VAC 50/60Hz, or 440VAC 60Hz.