11
FINAL WORDS
11.4 HOW MANY TELEPHONES?
Although it is quite possible to have any number of sockets
on
your tele
phone circuit, connecting a telephone
to
all of them may have undesirable
results.
The British Telecom circuit provides only a relatively small current to
make the telephone "ring". To make sure that each of the telephones you
connect to your circuit receives a sufficiently strong share of the total cur
rent, you may have to limit the total number of telephones on the circuit.
You can calculate the total number that will operate correctly providing
you know each of the telephones "Ringer Equivalence Number" - or REN.
A standard circuit should provide enough current for any number of tele
phones providing that their REN's add up to no more than
4.
The Sceptre
120
has a ringer equivalence number
(REN)
of
1.0.
Any
other
i
nstrumen
t
provided by British Telecom may be assumed to have a
REN
of
1
unless stated otherwise.
11.5 APPROVED SWITCHBOARDS FOR THE SCEPTRE 120
The
Sceptre
120
is approved
for
connection to the following switchboards:
MULTI-FREQUENCY VERSION WITH EARTH RECALL**
PABX's
Pen1omatP1000CT ARD561,2 AKD791,2.3 EBXBOOOPDXS00.2000 OCS300 SL-1 IDX(TDX) Monarch
Kins
m
an (Royale.
SX20) Regent (Royale. SX200)
Viceroy
PMBX's
3+ tO' 5+20"
10+30' 10+50" 10+60" 1A. 1B,4, 11
2
MUL Tl-FREQUENCY VERSION WITH TIME-BREAK RECALL**
PMBX's
3 +
10·
5 +
20· 10 + 30· 10 +so· 10 + eo·
C
o
r
r
ec1 operation will depend on the characteristics of the public exchange
.. The Scep1re
120
is supplied preset in the earth recall mode
If
your switchboard operates in the time-break
recall mode. you'll require lhe ass1s1ance of a qualified engineer 1n order 10 reset lhe Scep1re
If
you require
a v1s1t from a British Telecom engineer. there may be a charge for lhe work involved Please contact your local
Br111sh Telecom Sales Office for
more
1
n
for
ma
t1o
n