Ren And Sen Numbers - Honeywell Galaxy 2 Series Installation Manual

System Wiring (cont'd)

REN and SEN Numbers

It is possible to simultaneously connect a number of items to one line of the PSTN. The limit is determined by
summing the Ringer Equivalence Number (REN) shown on each item of apparatus, ensuring that the sum of
RENs is not more than four.
The REN of the Galaxy 2 Series is one (1).
Assume that all British Telecom equipment has a REN of one unless otherwise marked.
More than one item of series apparatus may be connected to the Galaxy 2 Series ports marked phone. This is
limited by summing the Series Equivalence Number (SEN) shown on each item of series connected apparatus,
ensuring that the sum of the SENs is not more than one (1). The total series resistance, including cabling, must
not exceed 50 Ohms.
• The SEN of the Galaxy 2 Series is 0.3.
• Nominal series resistance is 90 milli-ohms.
• Nominal insertion loss is 0.1 dB.
It is recommended that the PSTN should have the following facilities:
• Outgoing calls only (when used as dialler only).
• Direct exchange.
• Tone dialling.
Galaxy 2 Series Installation Manual
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