1.7 INTERCOM MODE WIRING – SINGLE UNIT
Use this wiring diagram when a single 1812 is programmed for intercom mode and is connected
directly to another telephone or to an un-used C.O. port on a PBX or KSU type system.
Phone In - 1
Phone In - 2
Case Ground - 3
Phone Out - 4
Phone Out - 5
1812
Main
Terminal
Programmed for
INTERCOM MODE
1. When the 1812 is programmed for intercom mode, it provides the constant source of DC
voltage necessary for communication. The intercom mode also disconnects the phone in
terminals (1 and 2) since they are not used.
2. Be sure that the 1812 is programmed in the intercom mode when connecting the unit as
shown above.
3. Use only twisted pair telephone wire that has proper insulation for direct underground
burial. Do not use thinly insulated wire, even if the phone lines will be run in a conduit. Do
not make any splices to the phone lines. If splices are made, they must be soldered and
insulated in a watertight enclosure.
4. Surge protection is recommended on the phone out lines. Use DoorKing phone line surge
suppresser (p/n 1877-010) or equivalent.
1812-065-M-3-07
Page
19
