ATT System 25 Installation And Maintenance Manual

							INSTALLATION
Mount 858A or 2210A2 Adapters
To install these adapters, proceed as follows:
1.Using a wide blade screwdriver, pry off the upper adapter mounting
clip on the 617A Panel (Figure 2-18).
2.Fit the mounting clip on the top of the adapter.
3. Fit the adapter in the slot of the lower mounting clip.
4.Press the upper mounting clip back into the panel.
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							INSTALLATION
UPPER ADAPTER
MOUNTING
CLIP
Figure 2-18.Mounting Adapters 
						

							INSTALLATION
INSTALL MODULAR BULK POWER SUPPLY
(Optimal)
The 346 Modular Bulk Power Supply (MBPS) is a cost-effective and flexible
alternative to the KS-2291 1 power supply. The 346 MBPS can be used
where the wall-mounted (outlet) KS-2291 1 power supply cannot be used or
where multiple KS-2291 1 power supplies are required.
The 346 MBPS consists of the 346A Power Unit and 346A1 Power Panel. Up
to three 346A Power Units can be mounted in a power panel. Each 346A
Power Unit is capable of powering four terminals with adjuncts (“1 O w“
position), for a total of 12 terminals.Terminals powered by the 346A Power
Unit can be located up to 1000 feet from the unit.
The 346 MBPS should be installed near the SIP. Service to the ac outlet
powering the 346 MBPS must be a dedicated (nonswitched) 20-ampere line.
A maximum of four power panels can be connected to the 20-ampere line.
The AC Surge Suppressor (T11 Model 428) should be used with the 346A1
Power Panel.
INSTALL EQUIPMENT ROOM TRUNK CABLING
As mentioned earlier, all outside lines must be connected to the system
through connectorized network interfaces. These interfaces are connected to
wall-mounted trunk access equipment (TAE), and from there to the cabinets.
Connect Network Interfaces to TAE Blocks
The trunks and off-premises stations from the network interface must be cut
down on the TAE’s connecting blocks so that the trunks are grouped by type
(loop start, ground start,DID, and tie) at the connecting block. Each
connecting block can handle up to three groups of eight trunks or two groups
of four tie trunks.
Each group can contain only one type of trunk. For loop start, ground start,
and DID trunks, the first group of eight trunks goes to leg 1 of the splitter
cable; the second group of eight trunks goes to leg 2; and the third group of
eight trunks goes to leg 3. For tie trunks, the first group of four trunks goes
to leg 1 of the splitter cable; and the second group of four trunks goes to leg
2.
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							INSTALLATION
Tie trunks must be segregated on a separate block because a different
splitter cable is used. Also, off-premises stations must be segregated  one
700A Jack.
The first five trunks in each group of eight (loop start or ground start trunks
only) can be connected through an ETU to five power failure transfer stations.
However, all eight trunks are connected to, and pass through, the ETU.
The ETU also supports a DID make-busy function to the central office’s extra
pair (if required). Relay contacts for the DID make-busy function appear on
the 25th pair on the TAE block. The relay contacts are normally open. When
power fails, the contacts close, making all DID trunks appear busy to the
central office. This prevents the central office from taking the DID trunks out
of service.
A maximum of four ETUs are supported.For a system with more than one
ETU, apportion the emergency transfer trunks so that they are in the first
subgroup of five in each subgroup of eight trunks on a connecting block.
1.Connect an A25D 25-pair single-ended cable to each network
interface receptacle.
2. Cut down the other end of each cable on the top terminal row of a
700A Jack in groups of eight trunks (four for tie trunks), as described
above (see Note). Cut down the DID make-busy pair (if provided) to
terminals 49 and 50 on the block.
Note:Facilities used for off-premises stations, must be
segregated on one 700A Jack.
3.Install secondary wiring protectors (sneak current fuses) between the
bottom terminal rows on the 700A Jacks for each trunk cut down on
the top row. (Approved protectors are listed in Table 2-B, along with
their respective CPs.)
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							INSTALLATION
Connect Cabinets to TAE Blocks
The connections between the cabinets and the TAE blocks are made using
connectorized splitter cables.Make sure that each trunk group on each
connecting block is connected to the correct type of CP and protected with
its approved secondary protector (as shown in Table 2-B).
Central office trunks associated with emergency transfer and off-premises
stations (OPSs) are not connected directly to the cabinets.If you are
installing trunks that are to be used for OPS, see Off-Premises Stations in this
part.Also, to complete the procedure for installing trunks used for
emergency transfer, you must go to 
Install Emergency Transfer Units (ETUS)
in this part.
Connect Ground Start, Loop Start, and DID Trunks
A 3:1 connectorized splitter cable, WP90929, L1, is required to connect the
700A Jack to the cabinet for these trunks.
1.
2.
3.
4.
5.
6.
Install secondary protectors (see Table 2-B).
Using the cable label sheets provided (Figure 2-7), label the back of
the hood of each of the connectors (1, 2, and 3) on the three legs of
the splitter cable (see Note). Use an appropriate cabinet and slot
number label (CAB 1 SLOT9, for example).
Note:If one or more of the legs contain trunks that are to
be used for emergency transfer, do not label these
legs. Set the legs aside and go to 
Install Emergency
Transfer Units (HUS) 
in this part to complete the
installation of these trunks.
On connector O, install labels that correspond to those used on each
of the three splitter cable legs.Position the labels so that they will
be clearly visible after the cable is plugged in.
Plug connector O into the 700A Jack.
Except for legs containing trunks to be used for emergency transfer,
connect connectors 1, 2, and 3 to the cabinet.Connect only to
ZTN76 Ground Start, ZTN77 Loop Start, or TN753 DID CPs.
Repeat procedure as required.
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							INSTALLATION
Connect Tie Trunks
A 2:1 connectorized splitter cable, WP90929, L3, is required to connect the
700A Jack to the cabinet for tie trunks.
1.
2.
3.
4.
5.
6.
Install secondary protectors (see Table 2-B).
Using the cable label sheets provided (Figure 2-7), label the back of
the hood of each of the connectors (1 and 2) on the two legs of the
splitter cable.Use an appropriate cabinet and slot number label
(CAB 1 SLOT8, for example).
On connector O, install labels that correspond to those used on each
of the two splitter cable legs. Position the labels so that they will be
clearly visible after the cable is plugged in.
Plug connector 0 into the 700A Jack.
Plug connectors 1
Tie Trunk CP.
Repeat procedure
and 2 into the
as required.cabinet. Connect only to a TN760B
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							INSTALLATION
Install DS1
DS1 signaling allows a digital connection between the System 25 and other
PBXs, Central Offices, Toll Offices, off premise stations, and data end points
such as host computers. The TN767 emulates ground start, Ioopstart, tie and
DID Trunks in addition to off premises stations. The ZTN131 circuit pack
provides the required digital synchronization.The TN748 circuit pack will provide
the Touch Tone registers.
The term synchronization refers to an arrangement where by digital facilities
operate from a common clock.This allows the receiving facilities to keep the
digital signals in step or synchronized.Synchronization can be provided by the
system 25 any other PBX it is connected to, or by the CO being used by the
network, Synchronization must be properly engineered before installation is
begun. Each node must be aware of the synchronization plan so that it may be
properly administered.
The TN767 circuit pack generates a signal that is shaped in a manner that when
it reaches the cable it conforms to power specifications. The level of the signal
must be adjusted according to the cable distance. If the DS1 Interface
terminates at the cross connect field or at a CSU, the total cabling distance must
be used. If the DS1 Interface terminates on another PBX (direct connection), a
phantom point midway between the two PBXs should be used as the reference
point. The line equalization/compensation for S25 is set via administration
procedures from the SAT.
Connect S25 to Another On Premises PBX
When the S25 and the other PBX are in the same building, the cabling is broken
down into three different distance ranges. The first connection is for distances of
1310 feet or less. The second distance range is 1311 to 4310 feet which
requires the use of a Customer Service Unit (CSU) equipped with an Office
Repeater. The third distance range is greater than 4311 feet. It uses a CSU and
T1 line repeaters as required.
Direct Connection—Less Than 1310 Feet
Figures 2-19 and 2-20 show two different direct connections. Figure 2-19 is
normally used for connecting a S25 to another PBX that is virtually side by side.
Figure 2-20 is used for direct connections that involve more distance. Figure
2-20 shows two S25s but a DEFINITY G1 or G2, System 75, or System 85 can
be connected directly to the S25. Consult the System 85 installation manual
(555-103-104) or the DEFINITY G1 Wiring Guide (555-204-111) or the System
75 Wiring Guide (555-200-111) for the connection information for those PBXs.
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							INSTALLATION
Figure 2-19.Direct Connection (Side by Side)
NOTE: FOR DISTANCES OVER 50 FEET (15.2 M)
USE C6E CONNECTOR CABLE(S) BETWEEN
H600 307,G2 CONNECTOR CABLE AND DS1
TRUNK CIRCUIT PACK.
Figure 2-20.Direction Connection (Side by Side)
Connections Between 1311 and 4310 Feet
For distances between 1311 and 4310 feet, CSUs equipped with Office repeaters
must be used to regenerate the DS1 signal. See “Install CSU” section of this
manual for the installation instructions for the CSU. Figure 2-21 shows a
functional diagram of this connection.If the connection is being made between
the S25 and a DEFINITY G1 or G2, System 75, or System 85, refer to the
System 85 Installation Manual (555-1 03-104) or the DEFINITY G1 Wiring Guide
(555-201-1 11) or the System 75 Wiring Guide (555-200-111) for the connecting
information.
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							Figure 2-21.DS1 Connections—1311 to 4310 Feet
DS1 Connections—4311 Feet or More
For distances of more than 4311 feet, T1 line repeaters are required in
addition to the CSUs. See the “Install CSU” section of this manual for
installing the CSU.Figure 2-22 showsa functional diagram of this
connection. If the connection is being made between the S25 and a DEFINITY
G1 or G2, System 75, or System 85, refer to the System 85 Installation
Manual (555-1 03-1 04) or the DEFINITY G1 Wiring Guide (555-204-111) or the
System 75 Wiring Guide (555-200-111) for the connecting information.
CSU
(NOTE)PROTECTION
CIRCUIT
655 FEET
MAXIMUM
DS1 LINE
WITH
REPEATERS
DSX-1*
CSU
DS1
(NOTE)PROTECTION
CIRCUIT
655 FEET
MAXIMUM
NOTE : USE OF THE OFFICE REPEATER IS OPTIONAL DEPENDING
UPON THE DISTANCE TO THE FIRST T 1 REPEATER
*DSX-1 REFERS TO A PHYSICAL CROSS-CONNECT FOR DS1
SIGNALS
Figure 2-22.DS1 connections—4311 Feet or More
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							INSTALLATION
Off Premises Metallic (Cable) Connections
The connection between the System 25 and another DS1 interface is in most
cases a T1 line with repeaters.The proper lightning protection must be
provided (as shown in Table 2-B). Figure 2-23 shows a diagram of the off
premise cabling.
See the “install CSU” section of this manual for the
installation instructions for the CSU.
*DSX-1 REFERS TO A PHYSICAL CROSS-CONNECT FOR DS1 SIGNALS
Figure 2-23.DS1 Connections—Off Premise Cabling
Off Premises Non Metallic Connections
Many alternatives to DS1 metallic transmission facilities exist. Some of these
systems include Iightguide (fiber optics), microwave, infrared, and radio
waves.Other type transmission facilities can be used as long as they are
technically compatible and connected via the DS1 cross connect point.
Figure 2-24 shows a block diagram of non metallic cabling transmission
systems.
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