3. Installation
9752 Installation Guide
Page 32
497098 Issue 3
Ringer Equivalence Number
The Ringer Equivalence Number (REN) of the built-in communicator is 1. As a
guide to the number of items that can be simultaneously connected to an
exclusive line, the sum of the REN values should not exceed 4. A standard
telephone (as provided, for example, by BT in the UK) has a REN value of 1.
Safety Notice
Figure 25 identifies connectors for Safety Extra-Low Voltage (SELV) and
Telecommunications Network Voltage (TNV) circuits on the control unit's main
PCB. These terms are used in accordance with the definitions in Safety
Standard EN60 950.
The Installer must ensure that TNV terminals are connected
only
to other
circuits designated as TNV circuits (for example, the PTSN) and that SELV
terminals are connected
only
to other circuits designated as SELV circuits.
Strict adherence to the installation instructions will ensure that the equipment
continues to comply with the safety regulations to which it was approved.