User`s manual

PHONE WIRE
TWISTED PAIR
PHONE WIRE
TWISTED PAIR
Figure 2-1 Non-UL Wiring Options
Wire the keypads in the “star” or “home-
run” configuration, with each device being
wired directly back to the CCU (maximum
wire run 300 feet).
NOTE:
Only two wires may be connected to any given
terminal, and only two keypads can be powered
from a terminal; this means that the Keypad
Expansion Module must be used if more than two
keypads are used. Specific information is pro-
vided in “Installing Specific Devices,” which
follows the power considerations.
6.
Hardwired circuits may conform to either
Figure 2-2 or 2-3 (Open or Closed). The
end-of-line resistor is 1000 ohms. For
household fire applications, use UL listed
end-of-line resistors (AT&T part
#
846626109) and the Open Loop configu-
ration.
NOTE:
In the figures, the response to a “fault”
condition is determined by programming
Function Numbers (see
Fn#515 in
Chapter 3).
2-4 AT&T Security System 8300 Installer’s Manual
CCU
Terminal’
I
Open
contacts, no
Break in circuit
LJ
I
Close conducts or
short across
1 circuit produces
ALARM
1000
ohm
End-of-Line
Resistor
Figure 2-2 Open Loop (Fn#515 = 1)
7.
Hardwire smoke detectors requiring
interruptible power can be wired with
power directly from the INT PWR and GND
terminals for low power (75
mA maximum)
applications, other options are included
later in this section under Hardwired
Smoke Detectors. See the figure and
discussion at the end of this chapter.
CCU
Terminal
i
1000 ohm
End-of-Line
Resistor
-
- T --8-J i
Open contacts or
break in circuit
produces ALARM
-
u
Short across circuit
Produces a fault. See
F n#515, Section III
-
Figure 2-3
Closed Loop (Fn#515 = 0)