Ericsson Marconi OMS 870 Quick Reference Manual page 15

•
1.5.3.3 SELV Circuits
SELV Circuits are ports that have maximum DC working voltage
level less than 60Volt (42.4 VAC). In addition, the ports must not be
connected to telecommunication networks in the EN 60950 meaning
of the term (see CEI/ IEC 60950-1 2001-10 standard clause
1.2.13.8).
In practice, the electrical cables shall not exit the building. In
addition, the electrical cables shall connect to equipment that either:
•
•
•
1.5.3.4 Telecommunication Network
A metallically terminated transmission medium intended for
communication between equipment that may be located in separate
buildings, excluding:
•
•
•
TNV Circuit
A circuit which is in the equipment and to which the accessible area
of contact is limited and that is so designed and protected that,
under normal operating conditions and single fault conditions (see
CEI/IEC 60950-1 2001-10 standard clause 1.4.14), the voltages do
not exceed specified limit values.
1/1531-CRA 119 0513/30 Uen A 2007-11-15
Marconi OMS 870 R3.0 Quick Reference Guide
applied to the location and about any precautions that shall be
taken; and
Access is through the use of a tool or lock and key, or other
means of security, and is controlled by the authority responsible
for the location.
is installed in RAL or
shall not have electrical cables that exits the building unless
those ports are TNV circuits or
shall have a written consent or in other ways evident that its
connecting port towards the SELV circuit port is not a
telecommunication network.
the mains system for supply, transmission and distribution of
electrical power, if used as a telecommunication transmission
medium;
Cable Distribution System;
SELV Circuits connecting units of information technology
equipment.
1-11