Quote Originally Posted by Immulmen View Post
Never worked on a 25 pair phone [each phone had 50 wires going to it], or any single line phone, only business phones using a KSU. The Intertell ESP phones was 4 pair.
Premier/Intertel ESP's are 3-pair/6-wire (with one pair reversed or you'd pop the fuse on the STN card), I've got 3 cabinets sitting in the closet along with a heap of 24-button keysets w/LCD's. The local carrier (Sprint) was installing them all over the place when they were new. One of the Sprint technicians was friendly with us and would broker a deal for us when other businesses upgraded, we bought their old Intertel systems for spares. Finally upgraded 3 years ago (yeah we got our money's worth out of the old ESP system).