ATT System 25 Installation And Maintenance Manual

NOTES :
1.
2.
3.
4.
5.115V AC, 60 Hz, 15 AMP OUTLETS
(HUBBELL 5262 OR EQUIVALENT)
MUST BE LOCATED WITHIN 4 FEET
OF SYSTEM CABINETS.
MULTIPLE CABINET SYSTEMS REQUIRE
TWO QUAD OUTLETS, SINGLE CABINET
SYSTEMS REQUIRE ONE QUAD OUTLET.
ALLOW AT LEAST 24 INCHES OF SPACE
IN FRONT OF CABINETS. TABLE MUST
BE ABLE TO SUPPORT 250 POUNDS.
BACKBOARD IS 3/4 INCHES THICK BY
48 INCHES WIDE BY 96 INCHES LONG
(FOR MAXIMUM SYSTEM).
SYSTEM 25 CABINETS AND BACKBOARD
MUST BE LOCATED IN A RESTRICTED
ACCESS AREA.
RESTRICTED...

INSTALLATION
AC Power
All cabinets and any locally-connected System 25 peripheral equipment
(System Administration Terminal [SAT], Station Message Detail Recording
[SMDR] device, Digital Tape Unit [DTU]), and Customer Service Unit (CSU)
used for DS1 connections must be plugged into the common ac power outlet.
This outlet must have an associated ground block connected to an approved
building ground, using #6 AWG copper wire. (This ground block is the
system’s single-point ground.)
A 1-cabinet system...

INSTALLATION
3.
4.
metal frame of the building, a concrete encased ground, or a ground
ring. If these grounds are not available, the water pipe ground can
be supplemented by one of the following types of grounds.
l Metal underground gas piping system—an electrically
continuous metal underground gas piping system that is
uninterrupted with insulating sections or joints and without
an outer nonconductive coating.
l Other local metal underground systems or structures—local
underground structures such as...

INSTALLATION
l A single-point ground (SPG) system in which the green wire ground
(system ground) and the telephone company ground are connected
to approved building ground.
l The coupled bonding conductor must be connected between the
telephone company ground at the building entrance and System 25’s
SPG.
l Surge protection on the ac power to System 25.
For greater than 99 percent of all lightning strikes, the protection outlined
above will do the job.However, there are a few locations where the
described...

INSTALLATION
Secondary Protection
External secondary protection,located at the trunk access area of the
System 25 cross-connect field, is required for all trunks and off-premises
lines. Refer to Table 2-B for approved trunk protectors.
FROM AC
LOAD CENTER
(TWO SEPARATELY
FUSED 15 AMP
CIRCUITS)
SINGLE
POINT
GROUND
HGROUNDI
LOAD
CENTER
II
(GREEN)
(#14 AWG)
I
/TO CABINET NO. 1
GROUND BAR MOUNTED ‘GROUND BLOCK (MAX.
ON 4“ BOX (SQUARE DLENGTH =20 FT.)
PK9GTA OR APPROVED
EQUIVALENT)4“ BOX (RACO 230
OR...

INSTALLATION
Building Wiring
Building (station) wiring (must be 24 AWG or heavier) from voice and data
terminals to the equipment location should already be in place. System 25
wiring requires that 4-pair circuits be distributed from the equipment location
to each station’s wall jack.The SIP hardware (Figures 2-2 through 2-6),
designed specifically for this purpose, is furnished with each system. Except
in extraordinary circumstances, this cross-connect hardware must be used.
In unusual circumstances...

INSTALLATION
INSTALL SYSTEM CABINETS
Before beginning the cabinet installation, position the cabinet table within 2
feet of the ac power receptacle. Make sure that the cabinets are easily
accessible from both the front and the back.
Position Cabinet(s)
Caution:A fully-equipped cabinet weighs 80 pounds.
1.
2.
3.
4.
Check
Unscrew and remove the upper rear panel of each
unscrew the lower part with the 12 connectors.
cabinet. Do not
Near the center of the backplane, note an address plug in one of the...

INSTALLATION
Table 2-B. Circuit Packs, Their Functions, and Protectors
Approved SecondaryCircuit PackFunction
Wiring Protector
N/AZTN78Supports single-line voice terminals.
(Must not be used on out-of-building
circuits, )
SCP-1 or 79ATN742Supports off-premises, out-of-
building, and bridged single-line
voice terminals.
lTW/LlNX343* I ROBZTN79Supports the 7300H Series voice
terminals used with a MERLIN®
system. (Requires local (set) power
for distances beyond 1000 feet.)
ITWILINX343* lROBTN735Supports MET...

INSTALLATION
Two fans are located on the left-hand front side of each cabinet. The
cabinet’s power supply is located behind the fans; to the right of the power
supply are up to 12 CPs in individual slots.Each CP is identified by a label
on the front. See Figure 2-10.
1.Remove the front cover of each cabinet.
2. Note any obviously bent or otherwise damaged circuit packs.
3. Check the CPs against the customer order. In case of irregularities
or damage, follow established notification procedures.
Danger:The...

INSTALLATION
Figure 2-10.Three-Cabinet System, Front View With Covers Removed
2-26