ISS 5, SECTION 512-700-100
SCREW TERMINALS FOR
CONNECTING TO KEY
AND TELEPHONE CIRCUITS
D20N CORD
TO 108-TYPE
LOUDSPEAKER
SET
M2FG CORD TO
8581 POWER
UNIT
Fig. 7-80-Type Control Unit With Cover Removed
contacts (s and t) are isolated from the oscillator
by the polarity guard.
3.02
Certain wiring precautions must be observed
when multipling sets wired for speakerphone.
The T1, R1, IR or P4, IT or P3, LK and AG leads
should be disconnected at or as close as possible
to the set in those stations not having speakerphone.
Even though none of the multipled sets have
speakerphone, the leads involved should be
disconnected. Failure to do so can result in:
•
Tip and ring cross through the T 1 and R1
leads
•
False operation of an A relay through the
AG lead
•
Shorting the receiver input to loudspeaker
set, disabling the loudspeaker through the
P3 and P4 leads.
3.03
An 85B1 power unit (UL approved) can be
used to power only one speakerphone system.
When power is provided via connector cable from
a remote location the 85B1 power unit should be
located less than 85 feet from the 108-type
loudspeaker set when using 26 gauge wire or less
than 125 feet from the 108-type loudspeaker set
when using 24 gauge wire.
3.04
A retaining clamp (841050818) (Fig. 1 and
2) should be mounted to the ac receptacle
to hold the power unit securely and to prevent
accidental loss of power.
Danger:
For safety, securely attach
retaining clamp to ac outlet using
outlet cover screw BEFORE attempting
to install 85Bl power unit.
See
Fig. 8.
The power unit and a n y
other cord plugged into the a c outlet
should always be unplugged completely
from outlet BEFORE attempting to
attach or remove the clamp.
This
will prevent the possibility of a loosened
retainer clamp or metallic outlet cover
making contact with the ac prongs
of the 85Bl power unit when partially
withdrawn from outlet.
Do not use
retaining clamp on outlets where the
cover mounting screw holds the duplex
outlet in the box.
Warning: Care should be taken to
trim and dress leads connecting to
low voltage output of 85Bl power
u n i t t o a s s u r e t h a t i n a d v e r t e n t
connection t o conducting surfaces or
other power sources does not occur.
If more t h a n one p ower u n it i s
plugged into a multiple receptacle
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BSP S12-700-100-i05_1979-04-07 .jpg Scanned by Frank Harrell, (Cowboy Frank) Castle Rock, Colorado Feb 16, 2012 23:01:14
