Matrix Telecom SARVAM UMG System Manual page 29

You are recommended to use the "Primary Protection Module - PPM4" supplied by Matrix.
MAIN BUILDING
PPM4
CO Lines
Distribution Frame
CO Lines
Extensions ETERNITY GENX
EARTH
ADJACENT BUILDING
PPM4
EARTH
Connecting Primary Protection Modules to Trunk and Overhead/Off-
Premises Lines
It is necessary to protect the ETERNITY GENX from heavy voltages entering the system from the Trunk Lines and
overhead stations.
The protection can be in the form of surge suppressor devices like Gas Discharge Tubes (GDT), MOVs, Fuses, etc.
Input Protection Modules (IPM)
Install IPM on the Krone Modules of the MDF. Input protection modules are for analog input channels to protect
against over-voltages that may be applied between any two input connectors or between an input connector and
the ground.
Primary Protection Module - PPM4
Matrix provides Primary Protection Modules (PPM) consisting of four PPM circuits. The PPM4 contains Gas
Discharge Tubes and Fuses.
The Gas Discharge Tube is an over voltage protection device. It has three terminals. It is connected parallel to the
CO Line or the overhead station cable. The third terminal is connected to a telecom earth. When the voltage
between any of the two terminals exceeds the permissible limit (general 150V), the gas in the device begins to
conduct and connects the terminals with the earth terminal. Heavy voltage passes to the earth instead of entering
the system, thereby protecting the system.
23 Matrix SARVAM UMG System Manual