MIL-HDBK-1191
11.5.1.1
Facilities. The following will be provided when a TSS is
installed: service entrance conduits, a main distribution frame (MDF), a 5 ohm
(maximum) signal grounding system in accordance with MIL-HNBK-419 and NFPA 70,
power from the emergency life safety branch and a DC power supply consisting
of dual rectifiers and sealed, low maintenance batteries. Batteries shall
have a minimum capacity of two hours at full load. Each rectifier shall be
sized to simultaneously operate the fully loaded TSS and charge the batteries.
Multiple element surge protectors shall be installed on the AC input to the
telephone system. These devices shall provide clamping to limit any
transients and surges on the line to prevent damage to the rectifiers and the
telephone system. In locations where the Installation AC system is known to
have problems with high transients and voltage variations on the network,
power conditioners shall be installed on the AC input to the telephone system.
A pre action sprinkler system will be provided in the telephone system
equipment room, see section 13 for sprinkler system criteria. When the
sprinkler system is activated the AC and DC power to the telephone system will
be automatically disconnected. The room shall be designed in accordance with
EIA/TIA 569 and be large enough to accommodate the telephone system and all
support equipment and have adequate equipment access, clearance and work
space. The electrical and air conditioning services for the telephone system
equipment room shall be sized to accommodate the worst case commercial system
based on the telephone system maximum operational capacity. The complete air
conditioning system for this room will be powered from the equipment branch of
the emergency power system.
11.5.1.2
Telephone system line/port count. Line and port as used in this
Military Handbook have the same meaning. Since a TSS has a digital computer
as a central control unit the point of connection for each external device
(telephone instrument or trunk circuit) is called a port. Each single line
telephone is connected to its own dedicated port which has a unique telephone
number. There will be no multiple connections of single line instruments to a
port. Each electronic feature phone is also connected to its own dedicated
port, however, due to the type of line circuit cards required for these units,
multiple telephone numbers can be assigned to each port. When making a line
count based on the Telephone Station Requirement Schedule (TSRS) data, each
single line phone will be counted as one line. This is reflected in the
number in the, "No. of Lines and Service Class," column for each room. Each
multi-line electronic feature phone shall also be counted as one line
regardless of the number of line entered in the, "No. of Lines and Service
Class," column in the TSRM.
11.5.1.3
TSS Subscriber Line/Port Capacity. The TSS subscriber port
capacity shall satisfy three different growth categories. The initially
installed capacity (IIC) shall equal the TSRS port count plus 15 percent
(minimum). The IIC refers to a fully equipped telephone system requiring only
the connection of telephone instruments to activate the port capacity
specified. The fully wired capacity (FWC) provides for expansion of the port
count beyond the IIC port size by requiring only the insertion of additional
subscriber line cards and connecting telephone instruments. The FWC shall
equal the TSRS port count plus 40 percent (minimum). The third category is
the maximum operational capacity (MOC) of the telephone system. The MOC shall
equal the IIC port count plus 100 percent (minimum). The MOC provides for
long term expansion of the facility by the addition of cabinets, power
supplies, processors, and other equipment to expand the telephone system
within its design limits. The IIC, FWC, and MOC port counts shall be included
in the telephone system specifications.
11-4
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