Clear-Com PSU-101 Rack Power Supply Module for IMF3 IntercomPSU 101 Power Supply for the IMF 3. (Does not power the Party Lines attached to CCI 22 modules. These require Encore Master Station PSUs such as the PK 7, PS 702 or MS 702). The PSU 101 is the power supply for the IMF 3 interface frame. It has both an audible failure alarm and failure relay contacts to activate a remote signal. A single PSU 101 will power a minimum of two interface frames, depending on the type of interfaces and their individual power