Alarm Connections
61181001L1-5E
21
Connecting Alarm Outputs
Depending on the vendor equipment employed at the CO, wiring external alarms from the
Total Access 3000 Chassis will vary slightly. The important consideration is whether the
external alarm equipment requires a Normally Open (NO) or Normally Closed (NC) circuit to
pass an alarm. After determining what the CO equipment requires, connection can be made to
the equipment from the Total Access 3000 Chassis, see
for location of alarm
contacts. To connect alarm outputs to the Total Access 3000 Chassis, perform the following
steps:
NOTE
Each three-pin alarm header is wired the same way for the
specified alarm.
1. Determine whether the external alarm reporting device uses a normally open or normally
closed circuit for alarm relay.
2. Using standard telco cross-connect wire, determine and cut the length required to reach
from the alarm headers to the alarm-reporting device.
3. Using wire strippers, strip 1 to 2 inches from both ends of the wire.
4. Using a wire-wrap gun, wire wrap one strand to the center pin (common) from the Total
Access alarm relay header, and the other strand to either the
NO
(normally open) or
NC
(normally closed) pin on the relay header.
5. Connect, using wire wrap or lugs, as appropriate, the two wires to the appropriate
terminals on the external alarm relay device being used.
NOTE
The AUX NO/C/NC alarm contacts are reserved for future use.
Connecting Miscellaneous Alarm Inputs
There are three additional external alarm inputs that can be reported to the SCU on the Total
Access 3000 chassis. These are labeled
ACO
,
RMT
and
AUX2
(if
AUX1
is being used for the fan
. Each functions in an identical manner to the fan alarm. Terminal B
supplies a –48 VDC source. Terminal A expects –48 VDC if an alarm condition exists on the
alarmed equipment.
To connect an external alarm input to the chassis, perform the following steps:
1. Choose an alarm header set from the
EXT INPUTS
block, P22, on the middle bottom of the
Total Access 3000 backplane.
2. Using standard telco cross-connect wire, determine and cut the length required to reach
from the alarmed piece of equipment to the header chosen. Allow length for 1 to 2 inches
of stripped wire for wire wrap, and neat routing out from the Total Access 3000 Chassis.
