[Code of Federal Regulations]
[Title 7, Volume 11]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 7CFR1755.397]

[Page 460-483]
 
                          TITLE 7--AGRICULTURE
 
    CHAPTER XVII--RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE
 
PART 1755--TELECOMMUNICATIONS STANDARDS AND SPECIFICATIONS FOR MATERIALS, EQUIPMENT AND CONSTRUCTION--Table of Contents
 
Sec. 1755.397  RUS performance specification for line concentrators.

    (a) General. (1) This section covers general requirements for a line 
concentrator (LC) system. This system shall operate in accordance with 
the manufacturer's specifications. Reliability shall be of prime 
importance in the design, manufacture and installation of the equipment. 
The equipment shall automatically provide for:
    (i) Terminating subscriber lines at a location remote from the 
serving central office;
    (ii) Concentrating the subscriber lines over a few transmission and 
supervisory paths to the serving central office; and
    (iii) Terminating the lines at the central office without loss of 
individual identity. A subscriber connected to a line concentrator shall 
be capable of having essentially the same services as a subscriber 
connected directly to the central office equipment (COE). Intra-unit 
calling among subscribers connected to the concentrator may be provided, 
but is not required.
    (2) Industry standards, or portions thereof, referred to in this 
paragraph (a) are incorporated by reference by RUS. This incorporation 
by reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552 (a) and 1 CFR part 51. Copies of these 
standards are available for inspection during normal business hours at 
RUS, room 2838, U.S. Department of Agriculture, Washington, DC 20250 or 
at the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.
    (3) American National Standards Institute (ANSI) standards are 
available from ANSI Inc., 11 West 42nd Street, 13th floor, New York, NY 
10036, telephone 212-642-4900.
    (i) ANSI Standard S1.4-1983, Specification for Sound Level Meters, 
including Amendment S1.4A-1985.
    (ii) [Reserved]
    (4) American Society for Testing Materials (ASTM) are available from 
1916 Race Street, Philadelphia, PA 19103, telephone 215-299-5400.
    (i) ASTM Specification B33-91, Standard Specifications for Tinned 
Soft or Annealed Copper Wire for Electrical Purposes.
    (ii) [Reserved]
    (5) Bell Communications Research (Bellcore) standards are available 
from Bellcore Customer Service, 8 Corporate Place, Piscataway, NJ 08854, 
telephone 1-800-521-2673.
    (i) TR-TSY-000008, Issue 2, August 1987, Digital Interface between 
the SLC 96 Digital Loop Carrier System and a Local Digital Switch.
    (ii) Bell Communications Research (Bellcore) document TR-TSY-000057, 
Issue 1, April 1987, including Revision 1, November 1988, Functional 
Criteria for Digital Loop Carrier Systems.
    (iii) Bell Communications Research (Bellcore) Document TR-NWT-
000303, Issue 2, December 1992, including Revision 1, December 1993, 
Integrated Digital Loop Carrier System Generic Requirements, Objectives, 
and Interface.
    (6) Federal Standard H28, Screw-Thread Standards for Federal 
Services, March 31, 1978, including Change Notice 1, May 28, 1986; 
Change Notice 2, January 20, 1989; and Change Notice 3, March 12, 1990. 
Copies may be obtained from the General Services Administration, 
Specification Section, 490 East L'Enfant Plaza SW, Washington, DC 20407, 
telephone 202-755-0325.
    (7) IEEE standards are available from IEEE Service Center, 445 Hoes 
Lane, P.O. Box 1331, Piscataway, NJ 08854, telephone 1-800-521-2673.

[[Page 461]]

    (i) IEEE Standard 455-1985, Standard Test Procedure for Measuring 
Longitudinal Balance of Telephone Equipment Operating in the Voice Band.
    (ii) [Reserved]
    (8) RUS standards are available from Publications and Directives 
Management Branch, Administrative Services Division, Rural Utilities 
Service, room 0180, South Building, U.S. Department of Agriculture, 
Washington, DC 20250-1500.
    (i) RUS Bulletin 345-50, PE-60 (Sept 1979), RUS Specification for 
Trunk Carrier Systems.
    (ii) [Reserved]
    (b) Types of requirements. (1) Unless otherwise indicated, the 
requirements listed in this section are considered to be fixed 
requirements.
    (2) The concentrator system shall communicate with standard T1 
digital transmission format at a minimum between the concentrator and 
central office terminals. Analog conversion functions at remote and 
central office terminals shall be capable of being eliminated to 
accommodate end-to-end digital transmission.
    (3) The LC shall operate properly as an integral part of the 
telephone network when connected to physical or carrier derived circuits 
and central offices meeting RUS specifications and other generally 
accepted telecommunications practices, such as Bellcore documents TR-
NWT-000303, Integrated Digital Loop Carrier System Generic Requirements, 
Objectives and Interface; TR-TSY-000008, Digital Interface between the 
SLC 96 Digital Loop Carrier System and a Local Digital Switch; and TR-
TSY-000057, Functional Criteria for Digital Loop Carrier Systems.
    (4) For RUS acceptance consideration of a LC, the manufacturer must 
certify and demonstrate that all requirements specified in this section 
are available and in compliance with this section.
    (5) Certain requirements are included in this section for features 
which may not be needed for every application. Such features are 
identifiable by the inclusion in the requirements of some such phrase as 
``when specified by the owner'' or ``as specified by the owner.'' In 
some cases where an optional feature will not be required by an owner, 
either now or in the future, a system which does not provide this 
feature shall be considered to be in compliance with the specification 
for the specific installation under consideration, but not in compliance 
with the entire specification.
    (6) The owner may properly request bids from any supplier of an RUS 
accepted LC whose system provides all the features which will be 
required for a specific installation.
    (7) When required by the owner, the supplier shall state compliance 
to the Carrier Serving Area (CSA) requirements, as stated in Bell 
Communications Research (Bellcore) Standard TR-TSY-000057, Functional 
Criteria for Digital Loop Carrier Systems.
    (c) Reliability. (1) The failure rate of printed circuit boards 
shall not exceed an average of 2.0 percent per month of all equipped 
cards in all system terminals during the first 3 months after cutover, 
and shall not exceed an average of 1.0 percent per month of all equipped 
cards in all system terminals during the second 3-month period. The 
failure rate for the equipment shall be less than 0.5 percent per month 
of all equipped cards in all system terminals after 6 months. A failure 
is considered to be the failure of a component on the PC board which 
requires it to be repaired or replaced.
    (2) The line concentrator terminal units shall be designed such that 
there will be no more than 4 hours of total outages in 20 years.
    (d) System type acceptance tests. General test results will be 
required on each system type. Any system provided in accordance with 
this section shall be capable of meeting any requirement in this section 
on a spot-check basis.
    (e) Features required. The network control equipment and peripheral 
equipment shall be comprised of solid-state and integrated circuitry 
components as far as practical and in keeping with the state-of-the-art 
and economics of the subject system.
    (f) Subscriber lines--(1) General. (i) The remote LC units shall 
operate satisfactorily with subscriber lines which meet all of the 
conditions under the bidder's specifications and all the requirements of 
this section. This section recognizes

[[Page 462]]

that the loop limit of the line concentrator is dependent upon the 
transmission facility between the LC central office termination and the 
LC remote unit. When voice frequency (physical) circuits are used, the 
loop limit from the COE to the subscriber shall be 1900 ohms (including 
the telephone set). When electronically derived circuits (carrier, 
lightwave, etc.) are used, the loop limits of the electronic system will 
control. The bidder shall identify the loop limits of the equipment to 
be supplied.
    (ii) There should be provisions for such types of lines as ground 
start, loop start, regular subscriber, pay stations, etc.
    (2) Dialing. (i) General. The line concentrator remote and central 
office terminal equipment shall satisfactorily transmit dialing 
information when used with subscriber dials having a speed of operation 
between 8 and 12 dial pulses per second and a break period of 55 to 65% 
of the total signaling period.
    (ii) Subscriber dial interdigital time. The remote and central 
office LC equipment shall permit satisfactory telecommunications 
operation when used with subscriber rotary dial interdigital times of 
200 milliseconds minimum, and pushbutton dialing with 50 milliseconds 
minimum.
    (iii) Subscriber line pushbutton dialing frequencies. The frequency 
pairs assigned for pushbutton dialing when provided by the central 
office shall be as listed in this paragraph (f)(2)(iii), with an 
allowable variation of 1.5 percent:

------------------------------------------------------------------------
                                        High group frequencies (Hz)
   Low group frequencies (Hz)    ---------------------------------------
                                   1209    1336    1477        1633
------------------------------------------------------------------------
697.............................       1       2       3  Spare.
770.............................       4       5       6  Spare.
852.............................       7       8       9  Spare.
941.............................       *       0  0.5 dB from the loss 
specified by the bidder.
    (6) Return loss. The specified return loss values are determined by 
the service and type of port at the measuring end. Two-wire ports are 
measured at 900 ohms in series with 2.16 microfarads, and 4-wire ports 
are measured at 600 ohms resistive. When other balance networks are 
supplied, test equipment arranged for operation with the supplied 
network(s) may be used. The requirement given shall meet the following 
cited values on each balance network available in the system:

Line-to-Line or Line-to-Trunk (2-Wire)
Echo Return Loss (ERL)--18 dB, Minimum
Singing Return Loss (SRL)--Low--15 dB, Minimum
Singing Return Loss (SRL)--High--18 dB, Minimum

    (7) Longitudinal balance. The minimum longitudinal balance, with dc 
loop currents between 20 to 70 mA, shall be 60 dB at all frequencies 
between 60 and 2000 Hz, 55 dB at 2700 Hz and 50 dB at 3400 Hz. The 
method of measurement shall be as specified in the IEEE standard 455, 
``Standard Testing Procedure for Measuring Longitudinal Balance of 
Telephone Equipment Operating in the Voice Band.'' Source voltage level 
shall be 10 volts root mean square (rms) where conversation battery feed 
originates at the remote end.
    (8) 60 hz longitudinal current immunity. The LC 60 Hz longitudinal 
current immunity shall be measured in accordance with Figure 1 of this 
section. Under test conditions cited on Figure 1 of this section, the 
system noise shall be 23 dBrnC or less as follows:

[[Page 464]]

[GRAPHIC] [TIFF OMITTED] TR29AU95.002

    (9) Steady noise (idle channel at 900 ohm impedance). Steady noise: 
Measure on terminated call. Noise measurements shall comply with the 
following:

Maximum--23 dBrnC0
Average--18 dBrnC0 or Less
3KHz Flat--Less than 35 dBrnO as an Objective

    (10) Impulse noise. LC central office terminal equipment shall have 
an impulse noise limit of not more than five counts exceeding 54 dBrnC0 
voice band weighted in a 5-minute period on six such measurements made 
during the busy hour. A WILCOM T-194C Transmission Test Set, or 
equivalent, should be used for the measurements. The

[[Page 465]]

measurement shall be made by establishing a normal connection from the 
noise counter through the switching equipment in its off-hook condition 
to a quiet termination of 900 ohms impedance. Office battery and 
signaling circuit wiring shall be suitably segregated from voice and 
carrier circuit wiring, and frame talking battery filters provided, if 
and as required, in order to meet these impulse noise limits.
    (11) Crosstalk coupling. Worst case equal level crosstalk shall be 
65 dB minimum in the range 200 to 3400 Hz. This shall be measured 
between any two paths through the system by connecting a 0 dBm0 level 
tone to the disturbing pair.
    (12) Digital error rate. The digital line concentrator shall not 
introduce more than one error in 10 \8\ bits averaged over a 5-minute 
period, excluding the least significant bit.
    (13) Quantizing distortion. (i) The system shall meet the following 
requirements:

------------------------------------------------------------------------
                                                  Minimum signal to
     Input level (dBm0) 1004 or 1020 Hz       distortion with C-message
                                                      weighting
------------------------------------------------------------------------
0 to -30...................................  33 dB
-30 to -40.................................  27 dB
-40 to -45.................................  22 dB
------------------------------------------------------------------------

    (ii) Due to possible loss of the least significant bit on direct 
digital connections, a signal to distortion degradation of up to 2 dB 
may be allowed where adequately justified by the bidder.
    (14) Overload level. The overload level shall be +3 dBm0.
    (15) Gain tracking (linearity) shall meet the following 
requirements:

------------------------------------------------------------------------
                                                               Maximum
                   Input signal level \1\                        gain
                                                              deviation
------------------------------------------------------------------------
+3 to -37 dBm0.............................................  0.5 dB
-37 to -50 dBm0............................................  1 dB
------------------------------------------------------------------------
\1\ 1004 Hz reference at 0 dBm0.

    (16) Frequency response (loss relative to 1004 Hz) for line-to-line 
(via trunk group or intra-link) connections shall meet the following 
requirements:

------------------------------------------------------------------------
              Frequency (Hz)                  Loss at 0 dBm0 input \1\
------------------------------------------------------------------------
60........................................  20 dB Min.\2\
300.......................................  -1 to +3 dB
600 to 2400...............................  +1 dB
3400......................................  -1 to +3 dB
------------------------------------------------------------------------
\1\ (-) means less loss and (+) means more loss.
\2\ Transmit End.

    (17) Envelope delay distortion. On any properly established 
connection, the envelope delay distortion shall not exceed the following 
limits:

------------------------------------------------------------------------
                      Frequency (Hz)                        Microseconds
------------------------------------------------------------------------
1000 to 2600..............................................         190
800 to 2800...............................................         350
600 to 3000...............................................         500
400 to 3200...............................................         700
------------------------------------------------------------------------

    (18) Absolute delay. The absolute one-way delay through the line 
concentrator, excluding delays associated with the central office 
switching equipment, shall not exceed 1000 microseconds analog-to-analog 
measured at 1800 Hz.
    (19) Insertion loss. The insertion loss in both directions of 
transmission at 1004 Hz shall be included in the insertion loss 
requirements for the connected COE switch and shall not increase the 
overall losses through the combined equipment beyond the values for the 
COE alone, when operated through a direct digital interface. Systems 
operated with a (VF) line circuit interface may introduce up to 3 dB 
insertion loss. Reference Sec. 1755.522(q)(3).
    (20) Detailed requirements for direct digital connections. (i) This 
paragraph (h)(20) covers the detailed requirements for the provision of 
interface units which will permit direct digital connection between the 
host central office and line concentrator subscriber terminals over 
digital facilities. The digital transmission system shall be compatible 
with T1 type span lines using a DS1 interface and other digital 
interfaces that may be specified by the owner. The RUS specification for 
the T1 span line equipment is PE-60. Other span line techniques may also 
be used. Diverse span line routing may be used when specified by the 
owner.
    (ii) The output of a digital-to-digital port shall be Pulse Code 
Modulation (PCM), encoded in eight-bit words using the mu-255 encoding 
law and D3 encoding format, and arranged to interface with a T1 span 
line.

[[Page 466]]

    (iii) Signaling shall be by means of Multifrequency (MF) or Dual 
Pulsing (DP) and the system which is inherent in the A and B bits of the 
D3 format. In the case where A and B bits are not used for signaling or 
system control, these bits shall only be used for normal voice and data 
transmission.
    (iv) When a direct digital interface between the span line and the 
host central office equipment is to be implemented, the following 
requirements shall be met:
    (A) The span line shall be terminated in a central office as a 
minimum a DS1 (1.544Mb/s) shall be provided;
    (B) The digital central office equipment shall be programmed to 
support the operation of the digital port with the line concentrator 
subscriber terminal;
    (C) The line concentrator subscriber terminal used with a direct 
digital interface shall be interchangeable with the subscriber terminal 
used with a central office terminal.
    (i) Alarms. The system shall send alarms for such conditions as 
blown fuses, blocked controls, power failure in the remote terminal, 
etc., along with its own status indication and status of dry relay 
contact closures or solid-state equivalent to the associated central 
office alarm circuits. Sufficient system alarm points shall be provided 
from the remote terminal to report conditions to the central office 
alarm system. The alarms shall be transmitted from the remote terminal 
to the central office terminal as long as any part of the connecting 
link is available for this transmission. Fuses shall be of the alarm and 
indicator type, and their rating designated by numerals or color code on 
fuse positions.
    (j) Electrical protection--(1) Surge protection. (i) Adequate 
electrical protection of line concentrator equipment shall be included 
in the design of the system. The characteristics and application of 
protection devices must be such that they enable the line concentrator 
equipment to withstand, without damage or excessive protector 
maintenance, the dielectric stresses and currents that are produced in 
line-to-ground and tip-to-ring circuits through the equipment as a 
result of induced or conducted lightning or power system fault-related 
surges. All wire terminals connected to outside plant wire or cable 
pairs shall be protected from voltage and current surges.
    (ii) Equipment must pass laboratory tests, simulating a hostile 
electrical environment, before being placed in the field for the purpose 
of obtaining field experience. For acceptance consideration RUS requires 
manufacturers to submit recently completed results (within 90 days of 
submittal) of data obtained from the prescribed testing. Manufacturers 
are expected to detail how data and tests were conducted. There are five 
basic types of laboratory tests which must be applied to exposed 
terminals in an effort to determine if the equipment will survive. 
Figure 2 of this section, Summary of Electrical Requirements and Tests, 
identifies the tests and their application as follows:

[[Page 467]]



                                                 Figure 2.--Summary of Electrical Requirements and Tests
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                  Number of
                Test                  Application criteria       Peak voltage or        Surge waveshape        applications and           Comments
                                                                     current                                 maximum time between
--------------------------------------------------------------------------------------------------------------------------------------------------------
Current surge......................  Low impedance paths     500A or lesser current  10x1000 [mu]s........  5 each polarity at 1   None.
                                      exposed to surges.      (see fig. 4).                                  minute intervals.
60 Hz current carrying.............  High or low impedance   10A rms or lesser       11 Cycles of 60 Hz     3 each at 1 minute     None.
                                      paths exposed to        current (see fig. 6).   (0.183 Sec.).          intervals.
                                      surges.
AC Power service surge voltage.....  AC power service        2500V or +3 [sigma]     1.2x50 [mu]s.........  5 each polarity at 1   AC arrester, if used,
                                      connection.             clamping V of                                  minute intervals.      must be removed.
                                                              arrester employed at                                                  Communications line
                                                              10kV/[mu]s.                                                           arresters, if used,
                                                                                                                                    remain in place.
Voltage surge......................  High impedance paths    1000V or +3 [sigma] dc  10x1000 [mu]s........  5 each polarity at 1   All primary
                                      exposed to surges.      breakdown of arrester                          minute intervals.      arresters, if used,
                                                              employed.                                                             must be removed.
Arrester response delay............  Paths protected by      +3 [sigma] breakdown    100V/[mu]s rise decay  5 each polarity at 1   All primary
                                      arresters, such as      of arrester employed    to \1/2\ V. in         minute intervals.      arrestors, if used,
                                      gas tubes, with         at 100V/[mu]s of rise.  tube's delay time.                            must be removed.
                                      breakdown dependent
                                      on V. rate of rise.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 468]]

    (iii) Electrical protection requirements for line concentrator 
equipment can be summarized briefly as follows:
    (A) Current surge tests simulate the stress to which a relatively 
low impedance path may be subjected before main frame protectors break 
down. Paths with a 100 Hz impedance of 50 ohms or less shall be 
subjected to current surges, employing a 10x1000 microsecond waveshape 
as defined in Figure 3 of this section, Surge Waveshape. For the purpose 
of determining this impedance, arresters which are mounted within the 
equipment are to be considered zero impedance. The crest current shall 
not exceed 500A; however, depending on the impedance of the test 
specimen this value of current may be lower. The crest current through 
the sample, multiplied by the sample's 100 Hz impedance, shall not 
exceed 1000 V. Where sample impedance is less than 2 ohms, peak current 
shall be limited to 500A as shown in Figure 4 of this section, Current 
Surge Tests. Figures 3 and 4 follow:
[GRAPHIC] [TIFF OMITTED] TR29AU95.003


[[Page 469]]


[GRAPHIC] [TIFF OMITTED] TR29AU95.004

    (B) Sixty Hertz (60 Hz) current carrying tests shall be applied to 
simulate an ac power fault which is conducted to the unit over the cable 
pairs. The test shall be limited to 10 amperes Root Mean Square (rms) of 
60 Hz ac for a period of 11 cycles (0.1835 seconds) and shall be applied 
longitudinally from line to ground.
    (C) AC power service surge voltage tests shall be applied to the 
power input terminals of ac powered devices

[[Page 470]]

to simulate switching surges or lightning-induced transients on the ac 
power system. The test shall employ a 1.2x50 microsecond waveshape with 
a crest voltage of 2500 V. Communications line protectors may be left in 
place for these tests.
    (D) Voltage surge tests which simulate the voltage stress to which a 
relatively high impedance path may be subjected before primary 
protectors break down and protect the circuit. To ensure coordination 
with the primary protection while reducing testing to the minimum, 
voltage surge tests shall be conducted at a 1000 volts with primary 
arresters removed for devices protected by carbon blocks, or the +3 
sigma dc breakdown voltage of other primary arresters. Surge waveshape 
should be 10x1000 microseconds.
    (E) Arrester response delay tests are designed to stress the 
equipment in a manner similar to that caused by the delayed breakdown of 
gap type arresters when subjected to rapidly rising voltages. Arresters 
shall be removed for these tests, the peak surge voltage shall be the +3 
sigma breakdown voltage of the arrester in question on a voltage rising 
at 100 V per microsecond, and the time for the surge to decay to half 
voltage shall equal at least the delay time of the tube as explained in 
Figure 5 of this section, Arrester Response Delay Time as follows:
[GRAPHIC] [TIFF OMITTED] TR29AU95.005

    (iv) Tests shall be conducted in the following sequence. As not all 
tests are required in every application, non-applicable tests should be 
omitted:
    (A) Current Impulse Test;
    (B) Sixty Hertz (60 Hz) Current Carrying Tests;

[[Page 471]]

    (C) AC Power Service Impulse Voltage Test;
    (D) Voltage Impulse Test; and
    (E) Arrester Response Delay Time Test.
    (v) A minimum of five applications of each polarity for the surge 
tests and three for the 60 Hz Current Carrying Tests are the minimum 
required. All tests shall be conducted with not more than 1 minute 
between consecutive applications in each series of three or five 
applications to a specific configuration so that heating effects will be 
cumulative. See Figure 6 of this section, 60 Hz Current Surge Tests as 
follows:
[GRAPHIC] [TIFF OMITTED] TR29AU95.006


[[Page 472]]


    (vi) Tests shall be applied between each of the following terminal 
combinations for all line operating conditions:
    (A) Line tip to ring;
    (B) Line ring to ground;
    (C) Line tip to ground; and
    (D) Line tip and ring tied together to ground.
    (2) Dielectric strength.(i) Arresters shall be removed for all 
dielectric strength tests.
    (ii) Direct current potentials shall be applied between all line 
terminals and the equipment chassis and between these terminals and 
grounded equipment housings in all instances where the circuitry is dc 
open circuit from the chassis, or connected to the chassis through a 
capacitor. The duration of all dielectric strength tests shall be at 
least 1 second. The applied potential shall be at a minimum equal to the 
plus 3 sigma dc breakdown voltage of the arrester, provided by the line 
concentrator manufacturer.
    (3) Insulation resistance.Following the dielectric tests, the 
insulation resistance of the installed electrical circuits between wires 
and ground, with the normal equipment grounds removed, shall not be less 
than 10 megohms at 500 volts dc at a temperature of 68  deg.F (20 
deg.C) and at a relative humidity of approximately 50 percent. The 
measurement shall be made after the meter stabilizes, unless the 
requirement is met sooner. Arresters shall be removed for these tests.
    (4) Self-protection.(i) All components shall be capable of being 
continuously energized at rated voltage without injury. Design 
precautions must be taken to prevent damage to other equipment 
components when a particular component fails.
    (ii) Printed circuit boards or similar equipment employing 
electronic components should be self-protecting against external grounds 
applied to the connector terminals. Board components and coatings 
applied to finished products shall be of such material or so treated 
that they will not support combustion.
    (iii) Every precaution shall be taken to protect electrostatically 
sensitive components from damage during handling. This shall include 
written instructions and recommendations.
    (k) Miscellaneous--(1) Interconnect wire.All interconnect wire shall 
be of soft annealed tinned copper wire meeting the requirements of ASTM 
Specification B33-91 and of suitable cross-section to provide safe 
current carrying capacity and mechanical strength. The insulation of 
installed wire, connected to its equipment and frames, shall be capable 
of withstanding the same insulation resistance and dielectric strength 
requirements as given in paragraphs (j)(2) and (j)(3) of this section at 
a temperature of 120  deg.F (49  deg.C), and a relative humidity of 90 
percent.
    (2) Wire wrapped terminals.These terminals are preferred and where 
used shall be of a material suitable for wire wrapping. The connections 
to them shall be made with a wire wrapping tool with the following 
minimum number of successive non-overlapping turns of bare tinned copper 
wire in contact with each terminal:
    (i) 6 turns of 30 gauge;
    (ii) 6 turns of 26 gauge;
    (iii) 6 turns of 24 gauge; or
    (iv) 5 turns of 22 gauge.
    (3) Protection against corrosion. All metal parts of equipment 
frames, distributing frames, cable supporting framework and other 
exposed metal parts shall be constructed of corrosion resistant 
materials or materials plated or painted to render them adequately 
corrosion resistant.
    (4) Screws and bolts. Screw threads for all threaded securing 
devices shall be of American National Standard form in accordance with 
Federal Standard H28, unless exceptions are granted to the manufacturer 
of the switching equipment. All bolts, nuts, screws, and washers shall 
be of nickel-copper alloy, steel, brass or bronze.
    (5) Environmental requirements. (i) The bidder shall specify the 
environmental conditions necessary for safe storage and satisfactory 
operation of the equipment being bid. If requested, the bidder shall 
assist the owner in planning how to provide the necessary environment 
for the equipment.
    (ii) To the extent practicable, the following temperature range 
objectives shall be met:

[[Page 473]]

    (A) For equipment mounted in central office and subscriber 
buildings, the carrier equipment shall operate satisfactory within an 
ambient temperature range of 32  deg.F to 120  deg.F (0  deg.C to 49 
deg.C) and at 80 percent relative humidity between 50  deg.F and 100 
deg.F (10  deg.C and 38  deg.C); and
    (B) Equipment mounted outdoors in normal operation (with cabinet 
doors closed) shall operate satisfactorily within an ambient temperature 
range (external to cabinet) of -40  deg.F to 140  deg.F (-40  deg.C to 
60  deg.C) and at 95 percent relative humidity between 50  deg.F to 100 
deg.F (10  deg.C to 38  deg.C). As an alternative to the (60  deg.C) 
requirement, a maximum ambient temperature of 120  deg.F (49  deg.C) 
with equipment (cabinet) exposed to direct sunlight may be substituted.
    (6) Stenciling. Equipment units and terminal jacks shall be 
adequately designated and numbered. They shall be stenciled so that 
identification of equipment units and leads for testing or traffic 
analysis can be made without unnecessary reference to prints or 
descriptive literature.
    (7) Quantity of equipment bays. Consistent with system arrangements 
and ease of maintenance, space shall be provided on the floor plan for 
an orderly layout of future equipment bays. Readily accessible terminals 
will be provided for connection to interbay and frame cables to future 
bays. All cables, interbay and intrabay (excluding power), if 
technically feasible, shall be terminated at both ends by connectors.
    (8) Radio and television interference. Measures shall be employed by 
the bidders to limit the radiation of radio frequencies generated by the 
equipment so as not to interfere with radio, television receivers, or 
other sensitive equipment.
    (9) Housing. (i) When housed in a building supplied by the owner, a 
complete floor plan including ceiling height, floor loading, power 
outlets, cable entrances, equipment entry and travel, type of 
construction, and other pertinent information shall be supplied.
    (ii) In order to limit corrosion, all metal parts of the housing and 
mounting frames shall be constructed of suitable corrosion resistant 
materials or materials protectively coated to render them adequately 
resistant to corrosion under the climatic and atmospheric conditions 
existing in the area in which the housing is to be installed.
    (10) Distributing frame. (i) The line concentrator terminal 
equipment located at the central office shall be protected by the 
central office main distribution frame. The bidder may supply additional 
protection capability as appropriate. All protection devices (new or 
existing) shall be arranged to operate in a coordinated manner to 
protect equipment, limit surge currents, and protect personnel.
    (ii) The distributing frame shall provide terminals for terminating 
all incoming cable pairs. Arresters shall be provided for all incoming 
cable pairs, or for a smaller number of pairs if specified.
    (iii) The current carrying capacity of each arrester and its 
associated mounting shall coordinate with a 22 gauge copper 
conductor without causing a self-sustaining fire or permanently damaging 
other arrester positions. Where all cable pairs entering the housing are 
24 gauge or finer, the arresters and mountings need only 
coordinate with 24 gauge cable conductors.
    (iv) Remote terminal protectors may be mounted and arranged so that 
outside cable pairs may be terminated on the left or bottom side of 
protectors (when facing the vertical side of the MDF) or on the back 
surface of the protectors. Means for easy identification of pairs shall 
be provided.
    (v) Protectors shall have a ``dead front'' (either insulated or 
grounded) where live metal parts are not readily accessible.
    (vi) Protectors shall be provided with an accessible terminal of 
each incoming conductor which is suitable for the attachment of a 
temporary test lead. They shall also be constructed so that auxiliary 
test fixtures may be applied to open and test the subscriber's circuit 
in either direction. Terminals shall be suitable for wire wrapped 
connections or connectorized.
    (vii) If specified, each protector group shall be furnished with a 
factory assembled tip cable for splicing to the outside cable; the tip 
cable shall be 20 feet (6.1 m) in length, unless otherwise

[[Page 474]]

specified. Tip cable used shall be RUS accepted.
    (viii) Protector makes and types used shall be RUS accepted.
    (l) Power equipment--(1) General. When specified, batteries and 
charging equipment shall be supplied for the remote terminal of the line 
concentrator.
    (2) Operating voltage. (i) The nominal operating voltage of the 
central office and remote terminal shall be 48 volts dc, provided by a 
battery with the positive side tied to system ground.
    (ii) Where equipment is dc powered, it must operate satisfactorily 
over a range of 50 volts 6 volts dc.
    (iii) Where equipment is ac powered, it must operate satisfactorily 
over a range of 12010 volts or 22010 volts ac.
    (3) Batteries. (i) Unless otherwise specified by the owner, sealed 
batteries shall be supplied for the remote line concentrator terminal.
    (ii) The batteries shall have an ampere hour load capacity of no 
less than 8 busy hours. When an emergency ac supply source is available, 
the battery reserve may be reduced to 3 busy hours.
    (iii) The batteries shall be sealed when they are mounted in the 
cabinet with the concentrator equipment.
    (iv) When specified by the owner, battery heaters shall be supplied 
in a bidder-furnished housing.
    (4) Charging equipment. (i) One charger capable of carrying the full 
dc power load of the remote terminal shall be supplied unless otherwise 
specified by the owner.
    (ii) Charging shall be on a full float basis. The rectifiers shall 
be of the full wave, self-regulating, constant voltage, solid-state type 
and shall be capable of being turned on and off manually.
    (iii) When charging batteries, the voltage at the battery terminals 
shall be adjustable and shall be set at the value recommended for the 
particular battery being charged, provided it is not above the maximum 
operating voltage of the central office switching equipment. The voltage 
shall not vary more than 0.02 volt dc per cell between 10% 
load and 100% load. Between 3% and 10% load, the output voltage shall 
not vary more than 0.04 volt dc per cell. Beyond full load 
current the output voltage shall drop sharply. The above output voltage 
shall be maintained with input line voltage variations of plus or minus 
10 percent. Provision shall be made to manually change the output 
voltage of the rectifier to 2.25 volts per cell to provide an 
equalization charge on the battery.
    (iv) The charger noise, when measured with a suitable noise 
measuring set and under the rated battery capacitance and load 
conditions, shall not exceed 22 dBrnC. See Figure 7 of this section, 
Charger Noise Test as follows:

[[Page 475]]

[GRAPHIC] [TIFF OMITTED] TR29AU95.007

    (v) The charging equipment shall be provided with a means for 
indicating a failure of charging current whether due to ac power 
failure, an internal failure in the charger, or to other circumstances 
which might cause the output voltage of the charger to drop below the 
battery voltage. Where a supplementary constant current charger is used, 
an alarm shall be provided to indicate a failure of the charger.
    (vi) Audible noise developed by the charging equipment shall be kept 
to a minimum. Acoustic noise resulting from operation of the rectifier 
shall be expressed in terms of dB indicated on a sound level meter 
conforming to American National Standards Institute S1.4, and shall not 
exceed 65 dB (A-weighting) measured at any point 5 feet (1.5m) from any 
vertical surface of the rectifier.

[[Page 476]]

    (vii) The charging equipment shall be designed so that neither the 
charger nor the central office equipment is subject to damage in case 
the battery circuit is opened for any value of load within the normal 
limits.
    (5) Power panel. (i) Battery and charger control switches, dc 
voltmeters, dc ammeters, fuses and circuit breakers, supervisory and 
timer circuits shall be provided as required. Portable or panel mounted 
frequency meters or voltmeters shall be provided as specified by the 
owner.
    (ii) Power panels, cabinets and shelves, and associated wiring shall 
be designed initially to handle the line concentrator terminal when it 
reaches its ultimate capacity as specified by the owner.
    (iii) The power panel shall be of the ``dead front'' type.
    (6) Ringing equipment. The ringing system shall provide sufficient 
ringing on a bridged basis over the voltage and temperature limits of 
this section and over subscriber drops within the limits stated by the 
bidder. The ringing system shall be without operational problems such as 
bell tapping during dialing. The bidder shall state the minimum number 
(not less than two) of main station ringers that can be used for each 
ringing option available.
    (7) Interrupter equipment. The interrupter may be an integral part 
of the system or may be part of the associated central office equipment 
connected to the line concentrator central office terminal.
    (8) Special systems. Manufacturers of LC systems that operate by 
extending ringing current from the central office shall state their 
required input ringing (voltage and frequency) and the limitations on 
the connected subscriber loop.
    (m) Fusing requirements--(1) General.(i) The equipment shall be 
completely wired and equipped with fuses, trouble signals, and all 
associated equipment for the wire capacity of the frames or cabinets 
provided.
    (ii) Design precautions shall be taken to prevent the possibility of 
equipment damage arising from the insertion of an electronic package 
into the wrong connector or the removal of a package from any connector 
or improper insertion of the correct card in its connector.
    (2) Fuses. Fuses and circuit breakers shall be of an alarm and 
indicator type, except where the fuse or breaker location is indicated 
on the alarm printout. Their rating shall be designated by numerals or 
color codes on the fuse or the panel.
    (n) Trouble location and test--(1) Equipment. (i) Trouble 
indications in the system may be displayed in the form of lights on the 
equipment units or printed circuit boards.
    (ii) When required, a jack or other connector shall be provided to 
connect a fault or trouble recorder (printer or display).
    (2) Maintenance system. (i) The maintenance system shall monitor and 
maintain the system operation without interruption of call processing 
except for major failures.
    (ii) The maintenance system shall be arranged to provide the ability 
to determine trouble to an individual card, functional group of cards, 
or other equipment unit.
    (o) Spare parts. Lists of spare parts and maintenance tools as 
recommended by the bidder shall be provided. The cost of such tools and 
spare parts shall be indicated and shall not be included in the base 
price.
    (p) Drawings and printed material. (1) The bidder shall supply 
instructional material for each line concentrator system involved at the 
time of delivery of the equipment. It is not the intent of this section 
to require system documentation necessary for the repair of individual 
circuit boards.
    (2) Three complete sets of legible drawings shall be provided for 
each central office to be accessed. Each set shall include all of the 
following:
    (i) Drawings of major equipment items such as frames, with the 
location of major component items of equipment shown therein;
    (ii) Wiring diagrams indicating the specific method of wiring used 
on each item of equipment and interconnection wiring between items of 
equipment;
    (iii) Maintenace drawings covering each equipment item that contains 
replaceable parts, appropriately identifying each part by name and part 
number; and

[[Page 477]]

    (iv) Job drawings including all drawings that are individual to the 
particular line concentrator involved such as mainframe, power 
equipment, etc.
    (3) The following information shall also be furnished:
    (i) A complete index of required drawings;
    (ii) An explanation of electrical principles of operation of overall 
concentrator system;
    (iii) A list of tests which can be made with each piece of test 
equipment furnished and an explanation of the method of making each 
test;
    (iv) A sample of each form recommended for use in keeping records;
    (v) The criteria for analyzing results of tests and determining 
appropriate corrective action;
    (vi) A set of general notes on methods of isolating equipment faults 
to specific printed circuit cards in the equipment;
    (vii) A list of typical troubles which might be encountered, 
together with general indications as to probable location of each 
trouble; and
    (viii) All special line concentrator system grounding requirements.
    (4) When installation is to be done by the bidder a complete set of 
drawings shall be provided by the owner, such as floor plans, lighting, 
grounding and ac power access.
    (q) Installation and acceptance--(1) General. Paragraphs (q)(2)(i) 
through (q)(3)(xxi) of this section covers the general requirements for 
the installation of line concentrator equipment by the bidder, and 
outlines the general conditions to be met by the owner in connection 
with such installation work. The responsibilities apply in both the 
central office installation and remote terminal installations, unless 
otherwise noted.
    (2) Responsibilities of owner. The owner shall:
    (i) Allow the bidder and its employees free access to the premises 
and facilities at all hours during the progress of the installation;
    (ii) Provide access to the remote site and any other site for 
development work needed during the installation;
    (iii) Take such action as necessary to ensure that the premises are 
dry and free from dust and in such condition as not to be hazardous to 
the installation personnel or the material to be installed (not required 
when remote terminal is not installed in a building);
    (iv) Provide heat or air conditioning when required and general 
illumination in rooms in which work is to be performed or materials 
stored;
    (v) Provide suitable openings in buildings to allow material to be 
placed in position (not required when a remote terminal is not installed 
in a building);
    (vi) Provide the necessary conduit and commercial and dc-ac inverter 
output power to the locations shown on the approved floor plan drawings;
    (vii) Provide 110 volts a.c., 60 Hz commercial power equipped with a 
secondary arrester and a reasonable number of outlets for test, 
maintenance and installation equipment;
    (viii) Provide suitable openings or channels and ducts for cables 
and conductors from floor to floor and from room to room;
    (ix) Provide suitable ground leads, as designated by the bidder (not 
required when remote terminal is not installed in a building);
    (x) Provide the necessary wiring, central office ground and 
commercial power service, with a secondary arrester, to the location of 
an exterior remote terminal installation based on the voltage and load 
requirements furnished voltage and load requirements furnished by the 
bidder;
    (xi) Test at the owners expense all lines and trunks for continuity, 
leakage and loop resistance and ensure that all lines and trunks are 
suitable for operation with the central office and remote terminal 
equipment specified;
    (xii) Make alterations and repairs to buildings necessary for proper 
installation of material, except to repair damage for which the bidder 
or its employees are responsible;
    (xiii) Connect outside cable pairs on the distributing frame (those 
connected to protectors);
    (xiv) Furnish all line, class of service assignment, and party line 
assignment information to permit bidder to program the data base memory 
within a reasonable time prior to final testing;
    (xv) Release for the bidder's use, as soon as possible, such 
portions of the

[[Page 478]]

existing plant as are necessary for the proper completion of such tests 
as require coordination with existing facilities including facilities 
for T1 span lines with properly installed repeaters between the central 
office and the remote terminal installations;
    (xvi) Make prompt inspections as it deems necessary when notified by 
the bidder that the equipment, or any part thereof, is ready for 
acceptance;
    (xvii) Provide adequate fire protection apparatus at the remote 
terminal, including one or more fire extinguishers or fire extinguishing 
systems of the gaseous type, that has low toxicity and effect on 
equipment;
    (xviii) Provide necessary access ports for cable, if underfloor 
cabling is selected;
    (xix) Install equipment and accessory plant devices mounted external 
to the central office building and external to the repeater and other 
outside housings including filters, repeater housings, splicing of 
repeater cable stubs, externally mounted protective devices and other 
such accessory devices in accordance with written instructions provided 
by the bidder; and
    (xx) Make all cross connections (at the MDF or Intermediate 
Distribution Frame IDF) between the physical trunk or carrier equipment 
and the central office equipment unless otherwise specified in appendix 
A of this section.
    (3) Responsibilities of bidder. The bidder shall:
    (i) Allow the owner and its representatives access to all parts of 
the building at all times;
    (ii) Obtain the owner's permission before proceeding with any work 
necessitating cutting into or through any part of the building structure 
such as girders, beams, concrete or tile floors, partitions or ceilings 
(does not apply to the installation of lag screws, expansion bolts, and 
similar devices used for fastening equipment to floors, columns, walls, 
and ceilings);
    (iii) Be responsible for and repair all damage to the building due 
to carelessness of the bidder's workforce, exercise reasonable care to 
avoid any damage to the owner's switching equipment or other property, 
and report to the owner any damage to the building which may exist or 
may occur during its occupancy of the building;
    (iv) Consult with the owner before cutting into or through any part 
of the building structure in all cases where the fireproofing or 
moisture proofing may be impaired;
    (v) Take necessary steps to ensure that all fire fighting apparatus 
is accessible at all times and all flammable materials are kept in 
suitable places outside the building;
    (vi) Not use gasoline, benzene, alcohol, naphtha, carbon 
tetrachloride or turpentine for cleaning any part of the equipment;
    (vii) Be responsible for delivering the CO and remote terminal 
equipment to the sites where they will be needed;
    (viii) Install the equipment in accordance with the specifications 
for the line concentrator;
    (ix) Have all leads brought out to terminal blocks on the MDF (or 
IDF if stated in appendix A of this section) and have all terminal 
blocks identified and permanently labeled;
    (x) Use separate shielded type leads grounded at one end only unless 
otherwise specified by the owner or bidder or tip cables meeting RUS 
cable crosstalk requirements for carrier frequencies inside the central 
office;
    (xi) Group the cables to separate carrier frequency, voice 
frequency, signaling, and power leads;
    (xii) Make the necessary power and ground connections (location as 
shown in appendix A of this section) to the purchaser's power terminals 
and ground bus unless otherwise stated in appendix A of this section 
(ground wire shall be 6 AWG unless otherwise stated);
    (xiii) Place the battery in service in compliance with the 
recommendations of the battery manufacturer;
    (xiv) Make final charger adjustments using the manufacturer's 
recommended procedure;
    (xv) Run all jumpers, except line and trunk jumpers (those connected 
to protectors) unless otherwise specified in appendix A of this section;
    (xvi) Establish and update all data base memories with subscriber 
information as supplied by the owner until an agreed turnover time;

[[Page 479]]

    (xvii) Give the owner notice of completion of the installation at 
least one week prior to completion;
    (xviii) Permit the owner or its representative to conduct tests and 
inspections after installation has been completed in order that the 
owner may be assured the requirements for installation are met;
    (xix) Allow access, before turnover, by the owner or its 
representative, upon request, to the test equipment which is to be 
turned over as a part of the delivered equipment, to permit the checking 
of the circuit features which are being tested and to permit the 
checking of the amount of connected equipment to which the test circuits 
have access;
    (xx) Notify the owner promptly of the completion of work of the 
central office terminals, remote terminals or such portions thereof as 
are ready for inspection; and
    (xxi) Correct promptly all defects for which the bidder is 
responsible.
    (4) Information to be furnished by bidder. The bidder shall 
accompany its bid with the following information:
    (i) Two copies of the equipment list and the traffic calculations 
from which the quantities in the equipment list are determined;
    (ii) Two copies of the traffic tables from which the quantities are 
determined, if other than the Erlang B traffic tables;
    (iii) A block diagram of the line concentrator and associated 
maintenance equipment will be provided;
    (iv) A prescribed method and criteria for acceptance of the 
completed line concentrator which will be subject to review;
    (v) This special grounding requirements including the recommended 
configuration, suggested equipment and installation methods to be used 
to accomplish them;
    (vi) The special handling and equipment requirements to avoid damage 
resulting from the discharge of static electricity (see paragraph 
(j)(4)(iii) of this section) or mechanical damage during transit 
installation and testing;
    (vii) The location of technical assistance service, its availability 
and conditions for owner use and charges for the service by the bidder; 
and
    (viii) The identification of the subscriber loop limits available 
beyond the line concentrator.
    (5) Installation requirements. (i) All work shall be done in a neat, 
workmanlike manner. Equipment frames or cabinets shall be correctly 
located, carefully aligned, anchored, and firmly braced. Cables shall be 
carefully laid with sufficient radius of curvature and protected at 
corners and bends to ensure against damage from handling or vibration. 
Exterior cabinet installations for remote terminals shall be made in a 
permanent, eye-pleasing manner.
    (ii) All multiple and associated wiring shall be continuous, free 
from crosses, reverses, and grounds and shall be correctly wired at all 
points.
    (iii) An inspection shall be made by the owner or its 
representatives prior to performing operational and performance tests on 
the equipment, but after all installing operations which might disturb 
apparatus adjustments have been completed. The inspection shall be of 
such character and extent as to disclose with reasonable certainty any 
unsatisfactory condition of apparatus or equipment. During these 
inspections, or inspections for apparatus adjustments, or wire 
connections, or in testing of equipment, a sufficiently detailed 
examination shall be made throughout the portion of the equipment within 
which such condition is observed, or is likely to occur, to disclose the 
full extent of its existence, where any of the following conditions are 
observed:
    (A) Apparatus or equipment units failing to compare in quantity and 
type to that specified for the installation;
    (B) Apparatus or equipment units damaged or incomplete;
    (C) Apparatus or equipment affected by rust, corrosion or marred 
finish; and
    (D) Other adverse conditions resulting from failure to meet 
generally accepted standards of good workmanship.
    (6) Operational tests. (i) Operational tests shall be performed on 
all circuits and circuit components to ensure their proper functioning 
in accordance with appropriate explanation of the operation of the 
circuit.

[[Page 480]]

    (ii) All equipment shall be tested to ensure proper operation with 
all components connected in all possible combinations and each line 
shall be tested for proper ring, ring trip and supervision.
    (iii) All fuses shall be verified for continuity and correct rating. 
Alarm indication shall be demonstrated for each equipped fuse position. 
An already failed fuse compatible with the fuse position may be used.
    (iv) Each alarm or signal circuit shall be checked for correct 
operation.
    (v) A sufficient quantity of locally originating and incoming calls 
shall be made to demonstrate the function of the line concentrator 
including all equipped transmission paths. When intra-link calling is 
supplied, all intra-link transmission paths shall be demonstrated.
    (7) Acceptance tests and data required. (i) Data shall be supplied 
to the owner by the bidder in writing as a part of the final documents 
in closing out the contract as follows:
    (A) A detailed cross connect drawing of alarm to power board, 
central office battery to physical trunks or carrier system, wiring 
options used in terminals, channels, filters, repeaters, etc., marked in 
the owner's copy of the equipment manual or supplied separately;
    (B) The measured central office supply voltages applied to the 
equipment terminals or repeaters at the time the jack and test point 
readings are made and ac supply voltages where equipment is powered from 
commercial ac sources;
    (C) A list of all instruments, including accessories, by 
manufacturer and type number, used to obtain the data; and
    (D) The measurements at all jack or test points recommended by the 
manufacturer, including carrier frequency level measurements at all 
carrier terminals and repeaters where utilized.
    (ii) Data in the form of a checklist or other notations shall be 
supplied showing the results of the operational tests.
    (iii) The bidder shall furnish to the owner a record of the battery 
cell or multicell unit voltages measured at the completion of the 
installation of the switching system before it is placed in commercial 
service. This is not required at a site where the owner furnishes dc 
power.
    (8) Joint inspection requirements. (i) The bidder shall notify the 
owner in writing at least one week before the date the complete system 
will be ready for inspection and tests. A joint inspection shall be made 
by the bidder and the owner (or owner's engineer) to determine that the 
equipment installation is acceptable. The inspection shall include 
physical inspection, a review of acceptance test data, operational 
tests, and sample measurements.
    (A) The owner shall review the acceptance test data and compare it 
to the requirements of this section.
    (B) Sample measurements shall be made on all systems installed under 
this contract. Test methods should follow procedures described in 
paragraph (g)(5) of this section.
    (C) A check shall be made of measured test point and jack readings 
for compliance with the manufacturer's specifications. This applies also 
to channels, terminals, carrier frequency repefault locating circuits.
    (ii) In the event that the measured data or operational tests show 
that equipment fails to meet the requirements quirements of this 
section, the deficiencies are to be resolved as set forth in Article II 
of the 397 Special Equipment Contract. (Copies are available from RUS, 
room 0174, U.S. Department of Agriculture, Washington, DC 20250-1500.) 
The reports of the bidder and the owner shall be detailed as to 
deficiencies, causes, corrective action necessary, corrective action to 
be taken, completion time, etc.

(The information and recordkeeping requirements of this section have 
been approved by the Office of Management and Budget (OMB) under the 
control number 0572-0059.)

    Appendix A to Sec. 1755.397--Specification for Line Concentrator 
                     Detailed Equipment Requirements

                  (Information To Be Supplied by Owner)

Telephone Company (Owner)

Name:___________________________________________________________________
Location:_______________________________________________________________

Number of LC's Required: --------
Line Concentrator Locations:

[[Page 481]]



------------------------------------------------------------------------
                                                   No. of      Central
                   Location                        Lines        Office
------------------------------------------------------------------------
                                                ...........  ...........
                                                ...........  ...........
                                                ...........  ...........
                                                ...........  ...........
------------------------------------------------------------------------

                               1. General

    1.1  Notwithstanding the bidder's equipment lists, the equipment and 
materials furnished by the bidder must meet the requirements of 
paragraphs (a) through (p) of this section, and this appendix A.
    1.2  Paragraph (a) through (p) of this section cover the minimum 
general requirements for line concentrator equipment.
    1.3  Paragraph (q) of this section covers the requirements for 
installation, inspection and testing when such service is included as 
part of the contract.
    1.4  This appendix A covers the technical data for application 
engineering and detailed equipment requirements insofar as they can be 
established by the owner. This appendix A shall be filled in by the 
owner.
    1.5  Appendix B of this section covers detailed information on the 
line concentrator equipment, information on system reliability and 
traffic capacity as proposed by the bidder. Appendix B of this section 
is to be filled in by the bidder and must be presented with the bid.

Office Name

(By Location)___________________________________________________________

LC Designation__________________________________________________________

2. Number of Subscriber Lines

------------------------------------------------------------------------
                                                                  Wired
                                                      Equipped    only
------------------------------------------------------------------------
Single-Party........................................  ........  ........
Pay Station (Type:--------).........................  ........  ........
Other (Describe:--------)...........................  ........  ........
      Total.........................................  ........  ........
------------------------------------------------------------------------

                           3. Loop Resistance

    3.1  Number of non-pay station lines having a loop resistance, 
including the telephone set as follows:
    3.1.1  For physical trunks between the remote and the office units, 
the loop resistance is to include the resistance of the trunk.

------------------------------------------------------------------------
                                                                No. of
                                                                lines
------------------------------------------------------------------------
1200-1900 ohms.............................................  ...........
1901-3200 ohms.............................................  ...........
3201-4500 ohms.............................................  ...........
------------------------------------------------------------------------

    3.1.2  Number of pay station lines having a loop resistance, 
excluding the telephone set, greater than:

------------------------------------------------------------------------
                                                                No. of
                                                                lines
------------------------------------------------------------------------
1200 ohms (Prepay).........................................  ...........
1000 ohms (Semi-Postpay)...................................  ...........
------------------------------------------------------------------------

    When physical trunks are used, these resistances include that of the 
facility between the CO and the remote.
    3.1.3  Range extension equipment, if required, is to be provided:

-------- By Bidder

-------- By Owner

(Quantity and Type)_____________________________________________________

________________________________________________________________________

                             4. Traffic Data

    4.1  Average combined originating and terminating hundred call 
seconds (CCS) per line in the busy hour:

------ CCS/Line. (Assume originating & terminating equal.)
    4.2  Percent Intra-Calling --------
    4.3  Total Busy Hour Calls --------

                           5. TYPE or RINGING


           5.1  Frequency No.               1.      2.      3.      4.

Frequency (Hz)..........................  ......  ......  ......  ......
Max. No. of Phones/Freq.................  ......  ......  ......  ......


    5.2 Minimum ringing generator capacity to be supplied shall be 
sufficient to serve -------- lines (each frequency).

                  6. Central Office Equipment Interface

    6.1  COE will be:
    6.1.1  COE Manufacturer

________________________________________________________________________

Type____________________________________________________________________

Year____________________________________________________________________

Generic_________________________________________________________________
    6.1.2 -------- See digital central office specification for the 
switchboard at -------------------- .
    6.2  Interface will be:
6.2.1  -------- Line Circuit(s)
6.2.2  -------- Direct Digital Interface
6.2.3  -------- Other (Describe)

________________________________________________________________________

________________________________________________________________________
    6.3  Mounting rack for line concentrator furnished by:

-------- Bidder

-------- Owner

(Specify width and height of rack available) (Width) (Height)
    6.4  Equipment to be installed in existing building:

-------- Yes (Attach detailed plan)

-------- No

                       7. Transmission Facilities

    7.1  Transmission facilities between the central office and remote 
terminals shall be:

[[Page 482]]

    7.1.1  Type:

-------- VF Carrier Derived Circuits

-------- Digital Span Line (DS1)

-------- Other

________________________________________________________________________

(Attach a layout of the transmission facilities between the central 
          office and the remote terminals describing transmission and 
          signaling parameters, routing and resistance where 
          applicable.)
    7.1.2  Utilizes physical plant

-------- Cable Pairs (Existing/New)

-------- Other

________________________________________________________________________
    Note: Unless otherwise stated, physical plant will be supplied by 
the owner.
    7.1.3  Terminal equipment for transmission facility to be supplied 
by:

-------- Owner

-------- Bidder
    7.1.3.1  Carrier e/w voice terminations -------- Yes -------- No

Manufacturer and type___________________________________________________
Central office voice terminations Equipped --------, Wired Only --------
    7.1.3.2  Digital span line (DS1) supplied by

-------- Owner

-------- Bidder

Manufacturer and Type___________________________________________________
    7.1.3.3  Number of repeaters (per span line) --------
    7.1.3.4  Diverse (alternate) span line routing required

-------- Yes (Describe in Item 11) -------- No
    7.1.3.5  Span line terminations only -------- Yes -------- No
    7.1.3.6  Span line power required (CO and Remote Terminals) -------- 
Yes -------- No
    7.1.3.7  Physical facility between CO and remote Loop Resistance --
------ ohms, Length -------- meters

                     8. Power Equipment Requirements

    8.1  Central Office Terminal
    8.1.1  Owner-furnished -48 volt dc power -------- Yes -------- No
    8.1.2  Other (Describe)
________________________________________________________________________
    8.1.3  Standby power is available -------- Yes -------- No
    8.2  Remote Terminal
    8.2.1  Owner-furnished -48 vdc power -------- Yes -------- No
    8.2.2  Bidder-furnished power supply -------- Yes -------- No
    8.2.3 AC power available at site:

-------- 110 vac, 60 Hz, single-phase

-------- Other (Describe in Item 11)
    8.2.4  A battery reserve of -------- busy hours shall be provided 
for this line concentrator terminal when it reaches -------- lines at 
the traffic rates specified.
    8.2.5  Batteries supplied shall be:

-------- Lead Calcium
-------- Stabilized Electrolyte
-------- Sealed Lead Acid
-------- Other (Describe in item 11)
    8.2.6  Standby power is available -------- Yes -------- No

                           9. Remote Terminal

    9.1  Mounting
    9.1.1  -------- Outside Housing (To be furnished by bidder)
    9.1.2  -------- Concrete Slab to be furnished by owner (Bidder to 
supply construction details after award.)
    9.1.3  -------- Manhole, environmentally controlled (Describe in 
Item 11)
    9.1.4  -------- Pedestal Mounting
    9.1.5  -------- Pole Mounting (Owner-furnished installed pole)
    9.1.6  -------- Prefab Building (Owner-furnished site)
    9.2  Equipment is to be installed in an existing building.

-------- Yes -------- No
(Attach detailed plan.)
    9.3  Other (Describe)
________________________________________________________________________

________________________________________________________________________

                             10. Alternates

                          11. Explanatory Notes

   Appendix B to Sec. 1755.397--Specification for Line Concentrators 
           Detailed Requirements; Bidder Supplied Information

Telephone Company (Owner)

Name:___________________________________________________________________

Location:_______________________________________________________________

Line Concentrator Equipment Locations

Central Office Terminal:________________________________________________

Remote Terminal:________________________________________________________

                               1. General

    1.1  The equipment and materials furnished by the bidder must meet 
the requirements of paragraphs (a) through (p) of this section.
    1.2  Paragraph (a) through (p) of this section cover the minimum 
general requirements for line concentrator equipment.
    1.3  Paragraph (q) of this section covers requirements for 
installation, inspection and testing when such service is included as 
part of the contract.
    1.4  Appendix A of this section covers the technical data for 
application engineering and detailed equipment requirements insofar as 
they can be established by the owner. Appendix A of this section is to 
be filled in by the owner.
    1.5  This appendix B covers detailed information on the line 
concentrator equipment, information as to system reliability and

[[Page 483]]

traffic capacity as proposed by the bidder. This appendix B shall be 
filled in by the bidder and must be presented with the bid.

                        2. Performance Objectives

    2.1  Reliability (See paragraph (c) of this section)

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________
    2.2  Busy Hour Load Capacity and Traffic Delay (See Paragraph (g) of 
this section)

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

           3. Equipment Quantities Dependent on System Design

    3.1  Transmission Facilities between the Central Office and Remote 
Terminals

------------------------------------------------------------------------
                                                  Quantity     Quantity
                     Type                         equipped    wired only
------------------------------------------------------------------------
                                                ...........  ...........
                                                ...........  ...........
                                                ...........  ...........
------------------------------------------------------------------------

                          4. Power Requirements

                      4.1  Central Office Terminal

Voltage_________________________________________________________________

Current Drain (Amps) Normal --------, Peak --------

Fuse Qty --------, Size --------, Type -------- 

Heat Dissipation (BTU/Hr.) -------- 
________________________________________________________________________

                          4.2  Remote Terminal

AC or DC________________________________________________________________

Voltage_________________________________________________________________

Current Drain (Amps) Normal --------, Peak --------

Fuse Qty --------, Size --------, Type --------

Heat Dissipation (BTU/Hr.) --------
________________________________________________________________________
    Power required for heating or cooling equipment in remote bidder-
furnished housing

________________________________________________________________________

________________________________________________________________________

                 5. Temperature and Humidity Limitations

                            5.1  Temperature

------------------------------------------------------------------------
                                                  Central
                                                   office      Remote*
------------------------------------------------------------------------
Maximum  deg.F (  deg.C)......................  ...........  ...........
Minimum  deg.F (  deg.C)......................  ...........  ...........
------------------------------------------------------------------------

                         5.2  Relative Humidity

------------------------------------------------------------------------
                                                  Central
                                                   office      Remote*
------------------------------------------------------------------------
Maximum.......................................  ...........  ...........
Minimum.......................................  ...........  ...........
------------------------------------------------------------------------
* Show conditions outside bidder-furnished housing.

                          6. Explanatory Notes

[60 FR 44729, Aug. 29, 1995]