RE: Re: Telephone wiring question : Max REN Count

["Keith Doxey" <ukha@xxxxxxxxxxx>]

> -----Original Message-----
> From: Hawes,Timothy Edward (GEG) [mailto:haweste@xxxxxxx]
>
> Keith D's probably got a much more accurate answer than me, but
> IIRC, as a manufacturer, you can't quote a REN less than 1.0,
> even if it is substantially lower then 1.0. Also IIRC, modern
> telephone equipment *is* much lower than 1.0, the REN was
> introduced (?) when phones still had bells etc. in them and drew
> more current from the line.
>

I have seen something that has a REN of less than 1 marked on it but I cant
remember what it was, I have also seen Fax machines with a REN of 3.

Depending on what phones you have then adjusting the ringer volume can also
affect the REN. For example, the old BT Viscount phone used less current
from the line at lower volume settings and presented no load to the bell
wire when switched off.

If you have a phone that was DESIGNED for the UK 3 wire system then by NOT
connecting terminal 3 in the socket will leave its ringer disconnected from
the line and it will have a REN of "0".

Generally speaking, if a phone is self-contained then its ringer is totally
powered from the line so it affects the REN rating. If a phone is powered
from an external power supply then it will probably have little effect on
the REN as it only needs to detect ringing. The actual ringing device is
probably powered from the power supply.

You can often get away with a REN of 6 without too much trouble. You wont
do
any harm by adding too many phones... they just wont ring properly.
Disconnect any ringers you dont need.

HTH

Keith



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