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Entry type: FAQ Entry ID: 31938455, Entry date: 10/23/2008

How do you protect a SINAUT MD3 dial-up network modem against overvoltage?

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Configuration Notes:
The modem has an overvoltage protection between the two signal lines "a" and "b". Overvoltage to protective ground is dangerous for the modem, because it always takes the path of least resistance.

If you do not have an overvoltage protective device, this path is always through the modem, which causes damage.

Overvoltage protection on both incoming telephone line wires protects the modem against destruction through overvoltage (see Fig. 01).
The overvoltage protective device limits the voltages to protective ground to harmless values.

Fig. 01

LTOPs are not suitable as overvoltage protective devices for dial-up networks. These are only suitable for dedicated lines. In the dial-up network, you can use the modules TAE-TRAB FM-NFN-AP or TAE-TRAB-FM-NFN from the "Phoenix Contact" company.

Please note that the protective device must be connected to the protective ground (building ground).

Overvoltage, Lightning protector, Telephone network, Protection, Dial-up network

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