RAD Data comm ASMi-52 User Manual

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Connection of Data and Telecommunications Cables 
Data and telecommunication interfaces are classified according to their safety status. 
The following table lists the status of several standard interfaces. If the status of a given port differs from 
the standard one, a notice will be given in the manual. 
 
Ports Safety 
Status 
V.11, V.28, V.35, V.36, RS-530, 
X.21, 10 BaseT, 100 BaseT, 
Unbalanced E1, E2, E3, STM, DS-2, 
DS-3, S-Interface ISDN, Analog voice 
E&M  
SELV  Safety Extra Low Voltage: 
 
Ports which do not present a safety hazard. Usually 
 
up to 30 VAC or 60 VDC. 
xDSL (without feeding voltage), 
Balanced E1, T1, Sub E1/T1 
TNV-1  Telecommunication Network Voltage-1: 
 
Ports whose normal operating voltage is within the 
 
limits of SELV, on which overvoltages from
 
telecommunications networks are possible. 
FXS (Foreign Exchange Subscriber) 
TNV-2  Telecommunication Network Voltage-2: 
 
Ports whose normal operating voltage exceeds the 
 
limits of SELV (usually up to 120 VDC or telephone 
 
ringing voltages), on which overvoltages from 
 
telecommunication networks are not possible. These 
 
ports are not permitted to be directly connected to 
 
external telephone and data lines. 
FXO (Foreign Exchange Office), xDSL 
(with feeding voltage), U-Interface 
ISDN 
TNV-3   Telecommunication Network Voltage-3: 
 
Ports whose normal operating voltage exceeds the 
 
limits of SELV (usually up to 120 VDC or telephone 
 
ringing voltages), on which overvoltages from 
 
telecommunication networks are possible. 
 
Always connect a given port to a port of the same safety status. If in doubt, seek the assistance of a 
qualified safety engineer. 
Always make sure that the equipment is grounded before connecting telecommunication cables. Do 
not disconnect the ground connection before disconnecting all telecommunications cables. 
Some SELV and non-SELV circuits use the same connectors. Use caution when connecting cables. 
Extra caution should be exercised during thunderstorms. 
When using shielded or coaxial cables, verify that there is a good ground connection at both ends. The 
earthing and bonding of the ground connections should comply with the local codes.  
The telecommunication wiring in the building may be damaged or present a fire hazard in case of 
contact between exposed external wires and the AC power lines. In order to reduce the risk, there are 
restrictions on the diameter of wires in the telecom cables, between the equipment and the mating 
connectors.