[Federal Register Volume 59, Number 113 (Tuesday, June 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-14338]
[[Page Unknown]]
[Federal Register: June 14, 1994]
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DEPARTMENT OF AGRICULTURE
Rural Electrification Administration
7 CFR Part 1755
REA Specification for Terminating Cables
AGENCY: Rural Electrification Administration, USDA.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The Rural Electrification Administration (REA) amends its
regulations on telecommunications standards and specifications for
materials, equipment and construction. The revised specification will
require that terminating cables comply with Article 800-50 of the 1993
National Electrical Code regarding fire retardancy of these products,
include raw material requirements for insulating and jacketing
compounds, and update the end product requirements associated with
these type cables.
DATES: Effective date: July 14, 1994.
Compliance date: Manufacturers of terminating cables will be
allowed until March 14, 1995 to supply borrowers with products already
produced or currently in the process of manufacturing under previous
Bulletin 345-87.
Incorporation by reference: Incorporation by reference of certain
publications listed in this final rule is approved by the Director of
the Federal Register as of July 14, 1994.
FOR FURTHER INFORMATION CONTACT: Garnett G. Adams, Chief, Outside Plant
Branch, Telecommunications Standards Division, Rural Electrification
Administration, room 2844, South Building, U.S. Department of
Agriculture, Washington, DC 20250-1500, telephone number (202) 720-
0667.
SUPPLEMENTARY INFORMATION:
Executive Order 12866
This final rule has been determined to be not significant for the
purposes of Executive Order 12866 and therefore has not been reviewed
by OMB.
Executive Order 12778
This final rule has been reviewed under Executive Order 12778,
Civil Justice Reform. If adopted, this final rule will not:
(1) Preempt any State or local laws, regulations, or policies;
(2) Have any retroactive effect; and
(3) Require administrative proceeding before parties may file suit
challenging the provisions of this rule.
Regulatory Flexibility Act Certification
The Administrator of REA has determined that this final rule will
not have a significant economic impact on a substantial number of small
entities, as defined by the Regulatory Flexibility Act (5 U.S.C. 601 et
seq.). This final rule involves standards and specifications, which may
increase the direct short term costs to REA borrowers. However, the
long-term direct economic costs are reduced through greater durability
and lower maintenance cost over time.
Information Collection and Recordkeeping Requirements
In compliance with the Office of Management and Budget (OMB)
regulations (5 CFR part 1320) which implements the Paperwork Reduction
Act of 1980 (Pub. L. 96-511) and section 3504 of that Act, information
collection and recordkeeping requirements contained in this final rule
have been submitted to OMB. Comments concerning these requirements
should be directed to the office of Information and Regulator Affairs
of OMB, Attention: Desk Officer for USDA, room 3201, New Executive
Office Building, Washington, DC 20503. When OMB has approved the
information collection and recordkeeping requirements contained in this
final rule, REA will publish an amendment to this final rule to add the
OMB control number and statement to the regulatory text.
National Environmental Policy Act Certification
The Administrator of REA has determined that this final rule will
not significantly affect the quality of the human environment as
defined by the National Environmental Policy Act of 1969 (42 U.S.C.
4321 et seq.). Therefore, this action does not require an environmental
impact statement or assessment.
Catalog of Federal Domestic Assistance
The program described by this final rule is listed in the Catalog
of Federal Domestic Assistance programs under No. 10.851, Rural
Telephone Loans and Loan Guarantees, and No. 10.852, Rural Telephone
Bank Loans. This catalog is available on a subscription basis from the
Superintendent of Documents, the United States Government Printing
Office, Washington, DC 20402-9325.
Executive Order 12372
This final rule is excluded from the scope of Executive Order
12372, Intergovernmental Consultation that requires intergovernmental
consultation with state and local officials. A Notice of Final rule
titled Department Programs and Activities Excluded from Executive Order
12372 (50 FR 47034) exempts REA and RTB loans and loan guarantees, and
RTB bank loans, to governmental and nongovernmental entities from
coverage under this Order.
Background
REA issues publications titled ``Bulletins'' which serve to guide
borrowers regarding already codified policy, procedures, and
requirements needed to manage loans, loan guarantee programs, and the
security instruments which provide for and secure REA financing. REA
issues standards and specifications for construction of telephone
facilities financed with REA loan funds. REA is rescinding Bulletin
345-87, REA Specification for Terminating (TIP) Cable, PE-87, and
codifying the revised specification at 7 CFR 1755.870, REA
Specification for Terminating Cables.
Terminating cables are used to connect the incoming outside plant
cables to the vertical side of the main distributing frame in a
telephone central office. Since these cables are installed inside of a
building, these cables are required to be listed in accordance with
Article 800-50 of the 1993 National Electrical Code (NEC). The current
specification does not require these cables to be listed in accordance
with Article 800-50 of the 1993 NEC. Therefore, REA is revising the
current specification to require these cables to be listed in
accordance with Article 800-50 of the 1993 NEC.
The current specification does not include insulation and jacketing
raw requirements, because these requirements were previously covered by
REA Bulletins 345-21, 345-51, and 345-58 which have since been
rescinded. Therefore, revision of the current specification is
necessary to incorporate essential jacketing and insulation raw
material requirements. By incorporating the raw material requirements
which were formerly found in REA Bulletins 345-21, 345-51, and 345-58
into 7 CFR 1755.870, a comprehensive document will be published for the
manufacture of terminating cable products.
The current specification contains end product performance
requirements that have become outdated for these type cables because of
the technological advancements made in the design of terminating cables
over the past ten years. Therefore, REA is revising the current
specification to update the end product performance requirements
associated with these cables to reflect the technological advancements
made in the design of these cables.
On November 17, 1993, REA published a proposed rule at 58 FR 220 to
rescind REA Bulletin 345-87, REA Specification for Terminating (TIP)
Cable, PE-87, and to codify the revised specification at 7 CFR
1755.870, REA Specification for Terminating Cables. Comments on this
proposed rule were due by December 17, 1993. Comments and
recommendations were received from one company by this due date. The
comments, recommendations, and responses are summarized as follows:
The first comment recommended that solid low density polyethylene
and expanded polyethylene insulating compounds should also be allowed
as an optional primary layer for the dual extruded insulated conductor.
Response: One reason REA 7 CFR 1755.870 requires dual insulated
conductors is to provide electrical stability and fire resistance of
the insulated conductors. The electrical stability of the insulated
conductor is provided by the primary layer which specifies the use of
either solid high density polyethylene or solid crystalline propylene/
ethylene copolymer insulating compounds. The fire resistance of the
insulated conductor is provided by the outer layer or skin which
specifies various types of polyvinyl chloride (PVC) insulating
compounds. REA chose to limit the primary layer of the dual insulated
conductor to either the solid high density polyethylene or the solid
crystalline propylene/ethylene copolymer insulating compounds because
these insulating compounds have proven histories of providing
satisfactory electrical stability of the dual insulated conductor over
time. Therefore, REA will not change 7 CFR 1755.870 to allow the use of
solid low density polyethylene and expanded polyethylene insulating
compounds as primary layers as recommended by the commenter.
The second comment recommended that 7 CFR 1755.870 should allow the
use of single insulated conductors using solid PVC insulating compounds
in addition to dual insulated conductors.
Response: Another reason REA requires the use of dual insulated
conductors for terminating cables is because these terminating cables
are presently being spliced to filled outside plant cables at REA
borrower construction projects. REA knows that the PVC outer skin of
the dual insulated conductor will degrade over time as a result of the
PVC's incompatibility with the filling compound used in filled cables.
REA also knows that the primary layer of the dual insulated conductor
will not degrade because the insulation materials used as the primary
layer of the dual insulated conductor are the same insulation materials
used as conductor insulations in filled cables which have been proven
to be compatible with the filling compound used in filled cables. Since
satisfactory signal transmission is dependent upon the integrity of the
primary layer of the dual insulated conductor in terminating cables
covered by 7 CFR 1755.870, REA must assure that the primary layer will
not degrade when these cables are spliced to filled outside plant
cables. If REA allowed the use of single insulated conductors using
solid PVC insulating compounds, signal transmission on these cables
would degrade as a result of the PVC's incompatibility with filling
compound when spliced to filled outside plant cables. Based on the
above reasons, REA will not allow the use of single insulated
conductors using PVC insulating compounds in 7 CFR 1755.870.
The next comment recommended that more restrictive volatile loss
requirements should be added to the PVC raw materials used as the outer
skin of the dual insulated conductors specified in 7 CFR 1755.870.
Response: The PVC raw materials used as the outer skin of the dual
insulated conductor presently specified in 7 CFR 1755.870 have been
used in these cables for a number of years with satisfactory results.
Since no problems with terminating cables using these PVC raw materials
have been encountered, REA will not add the more restrictive volatile
loss requirement to the PVC raw materials requirements specified in 7
CFR 1755.870 as recommended by the commenter.
The fourth comment recommended that test method for insulation
resistance (IR) specified in the American Society for Testing and
Materials (ASTM) D 4566-90 Standard be allowed as an alternative test
method for determining the insulation fault rate of the dual insulated
conductors.
Response: REA would like to point out that the IR test method for
determining the fault rate of the dual insulated conductors specified
in 7 CFR 1755.870 is same IR test method as specified in REA Bulletin
345-87. Since manufacturers have been using this IR test method for
determining the fault rate of the dual insulated conductors specified
in REA Bulletin 345-87 for more than eleven years without any reported
problems, REA will not change 7 CFR 1755.870 to allow the alternative
IR test method specified in ASTM D 4566-90 as a method for determining
the insulation fault of the dual insulated conductors.
The next comment recommended that the dual insulated conductor cold
bend test temperature specified in 7 CFR 1755.870 be changed from -40
1 deg.C to -20 1 deg.C.
Response: REA would like to point out that the -40 1
deg.C dual insulated cold bend test temperature specified in 7 CFR
1755.870 is same cold bend test temperature as specified in REA
Bulletin 345-87. Since manufacturers have been performing cold bend
tests on the dual insulated conductors using the -40 1
deg.C test temperature specified in REA Bulletin 345-87 for more than
eleven years without any reported problems, REA will not change the -40
1 deg.C cold bend test temperature specified in 7 CFR
1755.870 to the -20 1 deg.C cold bend test temperature
recommended by the commenter.
The sixth comment recommended that the PVC jacket raw material
requirements be eliminated from the specification.
Response: REA considers the PVC jacket raw material requirements
along with end product PVC jacket requirements to be critical
requirements to assure that the PVC jacket will withstand the rigors of
installation. Since REA considers PVC jacket raw material requirements
as one essential way of assuring that the PVC jacket will withstand the
rigors of installation, REA will not eliminate the PVC jacket raw
material requirements from 7 CFR 1755.870 as recommended by the
respondent.
The seventh comment from the respondent recommended that the
thicknesses of the outer jacket should be reduced to coincide with
other standards for these type cables.
Response: First, REA knows of no accepted American National
Standard for terminating cables. If REA was aware otherwise, REA would
reference the jacket thickness requirements of the national standard to
assist the industry in providing one cable design that could be used by
both REA and non-REA telephone operating companies. Since its REA's
knowledge, no accepted national standard exists, REA incorporated the
jacket thickness requirements presently specified in REA Bulletin 345-
87 into 7 CFR 1755.870 because these thickness requirements have been
used for REA terminating cables for over eleven years without any
reported field problems. Therefore, REA will not reduce the jacket
thickness requirements specified in 7 CFR 1755.870 to the
recommendation of the commenter.
The next comment recommended reducing the voice frequency
electrical requirements because the respondent feels that the voice
frequency electrical requirements specified in 7 CFR 1755.870 are too
stringent for voice frequency signal transmission.
Response: The voice frequency electrical requirements specified in
7 CFR 1755.870 were chosen to match voice frequency electrical
requirements of outside plant cables to provide satisfactory voice
frequency signal transmission. In addition the voice frequency
electrical requirements specified in 7 CFR 1755.870 are identical to
the voice frequency electrical requirements specified in REA Bulletin
345-87 which has been providing satisfactory voice frequency signal
transmission to REA borrowers for the past eleven years. Since REA
wanted the voice frequency electrical requirements of terminating
cables to match the voice frequency electrical requirements of outside
plant cables, REA will not reduce the voice frequency electrical
requirements of 7 CFR 1755.870 as recommended by the respondent.
The last comment from the respondent recommended that the test
voltages used to test dielectric strength between conductors and
dielectric strength between the cable core and shield be changed to
coincide with other industry specifications for these type cables.
Response: First, REA knows of no accepted American National
Standard for terminating cables. If such a standard did exist, REA
would reference the dielectric strength test voltages of the national
standard to assist the industry in providing one cable design that
could be used by both non-REA and REA telephone operating companies.
Since no accepted national standard exists, REA incorporated the
dielectric strength test voltages presently specified in REA Bulletin
345-87 into 7 CFR 1755.870 because these dielectric strength test
voltages have been used for REA terminating cables for over eleven
years without any reported problems. Therefore, REA will not change the
dielectric strength test voltages specified in 7 CFR 1755.870 to the
commenter's recommendation.
Although REA did not incorporate any of the respondent's
recommendations into 7 CFR 1755.870, REA did renumber paragraphs
(b)(3)(i) through (b)(12),(e)(2)(i) and (e)(2)(ii) to (b)(3) through
(b)(13),(e)(2), and (e)(3), respectively, to make these paragraph
numbers more user friendly to interested parties. No changes were made
to the technical requirements specified in the above mentioned
paragraphs.
List of Subjects in 7 CFR Part 1755
Incorporation by reference, Loan programs--communications,
Reporting and recordkeeping requirements, Rural areas, Telephone.
For reasons set out in the preamble, REA amends Chapter XVII of
title 7 of the Code of Federal Regulations as follows:
PART 1755--TELECOMMUNICATIONS STANDARDS AND SPECIFICATIONS FOR
MATERIALS, EQUIPMENT AND CONSTRUCTION
1. The authority citation for part 1755 continues to read as
follows:
Authority: 7 U.S.C. 901 et seq., 1921 et seq.
Sec. 1755.97 [Amended]
2. Section 1755.97 is amended by removing the entry REA Bulletin
345-87 from the table.
3. Section 1755.870 is added to read as follows:
Sec. 1755.870 REA specification for terminating cables.
(a) Scope. (1) This section establishes the requirements for
terminating cables used to connect incoming outside plant cables to the
vertical side of the main distributing frame in a telephone central
office.
(i) The conductors are solid tinned copper, individually insulated
with extruded solid dual insulating compounds.
(ii) The insulated conductors are twisted into pairs which are then
stranded or oscillated to form a cylindrical core.
(iii) The cable structure is completed by the application of a core
wrap, a shield, and a polyvinyl chloride jacket.
(2) The number of pairs and gauge size of conductors which are used
within the REA program are provided in the following table:
------------------------------------------------------------------------
American Wire Gauge (AWG) D22 24
------------------------------------------------------------------------
Number of Pairs........................................... 12 12
50 50
100 100
200 200
300 300
400 400
600 600
800 800
------------------------------------------------------------------------
Note: Cables larger in pair sizes from those shown in this table shall
meet all the requirements of this section.
(3) All cables sold to REA borrowers for projects involving REA
loan funds under this section must be accepted by REA Technical
Standards Committee ``A'' (Telephone). For cables manufactured to the
specification of this section, all design changes to an accepted design
must be submitted for acceptance. REA will be the sole authority on
what constitutes a design change.
(4) Materials, manufacturing techniques, or cable designs not
specifically addressed by this section may be allowed if accepted by
REA. Justification for acceptance of modified materials, manufacturing
techniques, or cable designs shall be provided to substantiate product
utility and long term stability and endurance.
(5) The American National Standard Institute/Electronic Industries
Association (ANSI/EIA) 359-A-84, EIA Standard Colors for Color
Identification and Coding, referenced in this section is incorporated
by reference by REA. 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 ANSI/EIA 359-A-84 are available for
inspection during normal business hours at REA, room 2845, U.S.
Department of Agriculture, Washington, DC 20250-1500 or at the Office
of the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC. Copies are available from Global Engineering Documents,
15 Inverness Way East, Englewood, CO 80112, telephone number (303) 792-
2181.
(6) American Society for Testing and Materials Specifications
(ASTM) B 33-91, Standard Specification for Tinned Soft or Annealed
Copper Wire for Electrical Purposes; ASTM B 736-92a Standard
Specification for Aluminum, Aluminum Alloy and Aluminum-Clad Steel
Cable Shielding Stock; ASTM D 1248-84 (1989), Standard Specification
for Polyethylene Plastics Molding and Extrusion Materials; ASTM D 1535-
89, Standard Test Method for Specifying Color by the Munsell System;
ASTM D 2287-81 (Reapproved 1988), Standard Specification for Nonrigid
Vinyl Chloride Polymer and Copolymer Molding and Extrusion Compounds;
ASTM D 2436-85, Standard Specification for Forced-Convection Laboratory
Ovens for Electrical Insulation; ASTM D 2633-82 (Reapproved 1989),
Standard Methods of Testing Thermoplastic Insulations and Jackets for
Wire and Cable; ASTM D 4101-82 (1988), Standard Specification for
Propylene Plastic Injection and Extrusion Materials; ASTM D 4565-90a,
Standard Test Methods for Physical and Environmental Performance
Properties of Insulations and Jackets for Telecommunications Wire and
Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance
Properties of Insulations and Jackets for Telecommunications Wire and
Cable; and ASTM E 29-90, Standard Practice for Using Significant Digits
in Test Data to Determine Conformance with Specifications, referenced
in this section are incorporated by reference by REA. These
incorporations by references were approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies of the ASTM standards are available for inspection during normal
business hours at REA, room 2845, U.S. Department of Agriculture,
Washington, DC 20250-1500 or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC. Copies are
available from ASTM, 1916 Race Street, Philadelphia, Pennsylvania
19103-1187, telephone number (215) 299-5585.
(7) American National Standards Institute/National Fire Protection
Association (ANSI/NFPA), NFPA 70-1993 National Electrical Code
referenced in this section is incorporated by reference by REA. 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. A copy
of the ANSI/NFPA standard is available for inspection during normal
business hours at REA, room 2845, U.S. Department of Agriculture,
Washington, DC 20250-1500 or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC. Copies are
available from NFPA, Batterymarch Park, Quincy, Massachusetts 02269,
telephone number 1 (800) 344-3555.
(8) Underwriters Laboratories Inc. (UL) 1666, Standard Test for
Flame Propagation Height of Electrical and Optical-Fiber Cables
Installed Vertically in Shafts, dated January 22, 1991, referenced in
this section is incorporated by reference by REA. 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. A copy of the UL
standard is available for inspection during normal business hours at
REA, room 2845, U.S. Department of Agriculture, Washington, DC 20250-
1500 or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC. Copies are available from UL
Inc., 333 Pfingsten Road, Northbrook, Illinois 60062-2096, telephone
number (708) 272-8800.
(b) Conductors and conductor insulation. (1) Each conductor shall
be a solid round wire of commercially pure annealed tin coated copper.
Conductors shall meet the requirements of the American Society for
Testing and Materials (ASTM) B 33-91 except that requirements for
Dimensions and Permissible Variations are waived.
(2) Joints made in conductors during the manufacturing process may
be brazed, using a silver alloy solder and nonacid flux, or they may be
welded using either an electrical or cold welding technique. In joints
made in uninsulated conductors, the two conductor ends shall be butted.
Splices made in insulated conductors need not be butted but may be
joined in a manner acceptable to REA.
(3) The tensile strength of any section of a conductor, containing
a factory joint, shall not be less than 85 percent of the tensile
strength of an adjacent section of the solid conductor of equal length
without a joint.
(4) Engineering Information: The sizes of wire used and their
nominal diameters shall be as shown in the following table:
------------------------------------------------------------------------
Nominal diameter
AWG -------------------------
Millimeters (Inches)
------------------------------------------------------------------------
22............................................ 0.643 (0.0253)
24............................................ 0.511 (0.0201)
------------------------------------------------------------------------
(5) Each conductor shall be insulated with a primary layer of
natural or white solid, insulating grade, high density polyethylene or
crystalline propylene/ethylene copolymer and an outer skin of colored,
solid, insulating grade, polyvinyl chloride (PVC) using one of the
insulating materials listed in paragraphs (b)(5)(i) through (iii) of
this section.
(i) The polyethylene raw material selected to meet the requirements
of this section shall be Type III, Class A, Category 4 or 5, Grade E9,
in accordance with ASTM D 1248-84 (1989).
(ii) The crystalline propylene/ethylene raw material selected to
meet the requirements of this section shall be Class PP 200B 40003 E11
in accordance with ASTM D 4101-82 (1988).
(iii) The PVC raw material selected to meet the requirements of
this section shall be either Type PVC-64751E3XO, Type PVC-76751E3XO, or
Type PVC-77751E3XO in accordance with ASTM D 2287-81 (1988).
(iv) Raw materials intended as conductor insulation furnished to
these requirements shall be free from dirt, metallic particles, and
other foreign matter.
(v) All insulating raw materials shall be accepted by REA prior to
their use.
(6) All conductors in any single length of cable shall be insulated
with the same type of material.
(7) A permissible overall performance level of faults in conductor
insulation when using the test procedures in paragraph (b)(8) of this
section shall average not greater than one fault per 12,000 conductor
meters (40,000 conductor feet) for each gauge of conductor.
(8) The test used to determine compliance with paragraph (b)(7) of
this section shall be conducted as follows:
(i) Samples tested shall be taken from finished cables selected at
random from standard production cable. The samples tested shall contain
a minimum of 300 conductor meters (1,000 conductor feet) for cables
sizes less than 50 pairs and 1,500 conductor meters (5,000 conductor
feet) for cables sizes greater than or equal to 50 pairs. No further
sample need be taken from the same cable production run within 6,000
cable meters (20,000 cable feet) of the original test sample from that
run.
(ii) The cable sample shall have its jacket, shield, and core wrap
removed and its core shall be immersed in tap water for a minimum
period of 6 hours. In lieu of removing the jacket, shield, and core
wrap from the core, the entire cable may be tested. In this case, the
core shall be completely filled with tap water, under pressure; then
the cable assembly shall be immersed for a minimum period of 6 hours.
With the cable core still fully immersed, except for end connections,
the insulation resistance (IR) of all conductors to water shall be
measured using a direct current (dc) voltage of 100 volts to 550 volts.
(iii) An IR value of less than 500 megohms for any individual
insulated conductor tested at or corrected to a temperature of 23
deg.C is considered a failure. If the cable sample is more than 7.5
meters (25 feet) long, all failing conductors shall be retested and
reported in 7.5 meter (25 foot) segments.
(iv) The pair count, gauge, footage, and number of insulation
faults shall be recorded. This information shall be retained on a 6
month running basis for review by REA when requested.
(v) A fault rate, in a continuous length in any one reel, in excess
of one fault per 3,000 conductor meters (10,000 conductor feet) due to
manufacturing defects is cause for rejection. A minimum of 6,000
conductor meters (20,000 conductor feet) is required to develop a
noncompliance in a reel.
(9) Repairs to the conductor insulation during manufacturing are
permissible. The method of repair shall be accepted by REA prior to its
use. The repaired insulation shall be capable of meeting the relevant
electrical requirements of this section.
(10) All repaired sections of insulation shall be retested in the
same manner as originally tested for compliance with paragraph (b)(7)
of this section.
(11) The colored composite insulating material removed from or
tested on the conductor, from a finished cable, shall be capable of
meeting the following performance requirements:
------------------------------------------------------------------------
Composite
Property insulation
------------------------------------------------------------------------
Tensile Strength, Minimum Megapascals (MPa) (Pounds per
square inch (psi))........................................ 16.5 (2400)
Ultimate Elongation Percent, Minimum....................... 125
Cold Bend Failures, Maximum................................ 0/10
Shrinkback, Maximum Millimeter (mm) (Inches (in.))......... 9.5 (3/8)
Adhesion, Maximum Newtons (N) (Pound-force (lbf)).......... 13.3 (3)
Compression Minimum, N (lbf)............................... 1780 (400)
------------------------------------------------------------------------
(12) Testing procedures. The procedures for testing the composite
insulation samples for compliance with paragraph (b)(11) of this
section shall be as follows:
(i) Tensile strength and ultimate elongation. Samples of the
insulation material, removed from the conductor, shall be tested in
accordance with ASTM D 2633-82(1989), except that the speed of jaw
separation shall be 50 millimeters/minute (50 mm/min) (2 inches/minute
(2 in./min)).
Note: Quality assurance testing at a jaw separation speed of 500
mm/min (20 in./min) is permissible. Failures at this rate shall be
retested at the 50 mm/min (2 in./min) rate to determine
specification compliance.
(ii) Cold bend. Samples of the insulation material on the conductor
shall be tested in accordance with ASTM D 4565-90a at a temperature of
-401 deg.C with a mandrel diameter of 6 mm (0.25 in.).
There shall be no cracks visible to normal or corrected-to-normal
vision.
(iii) Shrinkback. Samples of insulation shall be tested for four
hours at a temperature of 1151 deg.C in accordance with
ASTM D 4565-90a.
(iv) Adhesion. Samples of insulation material on the conductor
shall be tested in accordance with ASTM D 4565-90a with a crosshead
speed of 50 mm/min (2 in./min).
(v) Compression. Samples of the insulation material on the
conductor shall be tested in accordance with ASTM D 4565-90a with a
crosshead speed of 5 mm/min (0.2 in./min).
(13) Other methods of testing may be used if acceptable to REA.
(c) Identification of pairs and twisting of pairs. (1) The PVC skin
shall be colored to identify:
(i) The tip and ring conductor of each pair; and
(ii) Each pair in the completed cable.
(2) The colors used to provide identification of the tip and ring
conductor of each pair shall be as shown in the following table:
------------------------------------------------------------------------
Color
Pair No. ---------------------
Tip Ring
------------------------------------------------------------------------
1................................................. White Blue
2................................................. White Orange
3................................................. White Green
4................................................. White Brown
5................................................. White Slate
6................................................. Red Blue
7................................................. Red Orange
8................................................. Red Green
9................................................. Red Brown
10................................................ Red Slate
11................................................ Black Blue
12................................................ Black Orange
13................................................ Black Green
14................................................ Black Brown
15................................................ Black Slate
16................................................ Yellow Blue
17................................................ Yellow Orange
18................................................ Yellow Green
19................................................ Yellow Brown
20................................................ Yellow Slate
21................................................ Violet Blue
22................................................ Violet Orange
23................................................ Violet Green
24................................................ Violet Brown
25................................................ Violet Slate
------------------------------------------------------------------------
(3) Standards of color. The colors of the insulated conductors
supplied in accordance with this section are specified in terms of the
Munsell Color System (ASTM D 1535-89) and shall comply with the ``Table
of Wire and Cable Limit Chips'' as defined in ANSI/EIA-359-A-84.
(Visual color standards meeting these requirements may be obtained
directly from the Munsell Color Company, Inc., 2441 North Calvert
Street, Baltimore, Maryland 21218).
(4) Positive identification of the tip and ring conductors of each
pair by marking each conductor of a pair with the color of its mate is
permissible. The method of marking shall be accepted by REA prior to
its use.
(5) Other methods of providing positive identification of the tip
and ring conductors of each pair may be employed if accepted by REA
prior to its use.
(6) The insulated conductors shall be twisted into pairs.
(7) In order to provide sufficiently high crosstalk isolation, the
pair twists shall be designed to enable the cable to meet the
capacitance unbalance and the crosstalk loss requirements of paragraphs
(h)(2), (h)(3), and (h)(4) of this section.
(8) The average length of pair twists in any pair in the finished
cable, when measured on any 3 meter (m) (10 foot (ft)) length, shall
not exceed 152 mm (6 in.).
(d) Forming of the cable core. (1) Twisted pairs shall be assembled
in such a way as to form a substantially cylindrical group.
(2) When desired for lay-up reasons, the basic group may be divided
into two or more subgroups called units.
(3) Each group, or unit in a particular group, shall be enclosed in
bindings of the colors indicated for its particular pair count. The
pair count, indicated by the color of insulation, shall be consecutive
as indicated in paragraph (d)(5) of this section through units in a
group.
(4) Threads or tapes used as binders shall be nonhygroscopic and
nonwicking. The threads shall consists of a suitable number of ends of
each color arranged as color bands. When tapes are used as binders,
they shall be colored. Binders shall be applied with a lay of not more
than 100 mm (4 in.). The colored binders shall be readily recognizable
as the basic intended color and shall be distinguishable from all other
colors.
(5) The colors of the bindings and their significance with respect
to pair count shall be as shown in the following table:
------------------------------------------------------------------------
Group pair
Group No. Color of bindings count
------------------------------------------------------------------------
1............ White-Blue................................ 1-25
2............ White-Orange.............................. 26-50
3............ White-Green............................... 51-75
4............ White-Brown............................... 76-100
5............ White-Slate............................... 101-125
6............ Red-Blue.................................. 126-150
7............ Red-Orange................................ 151-175
8............ Red-Green................................. 176-200
9............ Red-Brown................................. 201-225
10........... Red-Slate................................. 226-250
11........... Black-Blue................................ 251-275
12........... Black-Orange.............................. 276-300
13........... Black-Green............................... 301-325
14........... Black-Brown............................... 326-350
15........... Black-Slate............................... 351-375
16........... Yellow-Blue............................... 376-400
17........... Yellow-Orange............................. 401-425
18........... Yellow-Green.............................. 426-450
19........... Yellow-Brown.............................. 451-475
20........... Yellow-Slate.............................. 476-500
21........... Violet-Blue............................... 501-525
22........... Violet-Orange............................. 526-550
23........... Violet-Green.............................. 551-575
24........... Violet-Brown.............................. 576-600
------------------------------------------------------------------------
(6) The use of the white unit binder in cables of 100 pair or less
is optional.
(7) When desired for manufacturing reasons, two or more 25 pair
groups may be bound together with nonhygroscopic and nonwicking threads
or tapes into super-units. The group binders and the super-unit binders
shall be colored such that the combination of the two binders shall
positively identify each 25 pair group from every other 25 pair group
in the cable.
(8) Super-unit binders shall be of the colors shown in the
following table:
Super-Unit Binder Colors
------------------------------------------------------------------------
Pair No. Binder color
------------------------------------------------------------------------
1-600.................................................. White
601-1200............................................... Red
------------------------------------------------------------------------
(e) Core wrap. (1) The core shall be completely covered with a
layer of nonhygroscopic and nonwicking dielectric material. The core
wrap shall be applied with an overlap.
(2) The core wrap shall provide a sufficient heat barrier to
prevent visible evidence of conductor insulation deformation or
adhesion between conductors, caused by adverse heat transfer during the
jacketing operation.
(3) Engineering Information: If required for manufacturing reasons,
white or uncolored binders of nonhygroscopic and nonwicking material
may be applied over the core and/or core wrap.
(f) Shield. (1) An aluminum shield, plastic coated on one side,
shall be applied longitudinally over the core wrap.
(2) The shield may be applied over the core wrap with or without
corrugations (smooth) and shall be bonded to the outer jacket.
(3) The shield overlap shall be a minimum of 3 mm (0.125 in.) for
cables with core diameters of 15 mm (0.625 in.) or less and a minimum
of 6 mm (0.25 in.) for cables with core diameters greater than 15 mm
(0.625 in.). The core diameter is defined as the diameter under the
core wrap and binding.
(4) General requirements for application of the shielding material
shall be as follows:
(i) Successive lengths of shielding tapes may be joined during the
manufacturing process by means of cold weld, electric weld, soldering
with a nonacid flux, or other acceptable means;
(ii) The metal shield with the plastic coating shall have the
coating removed prior to joining the metal ends together. After
joining, the plastic coating shall be restored without voids using good
manufacturing techniques;
(iii) The shields of each length of cable shall be tested for
continuity. A one meter (3 ft) section of shield containing a factory
joint shall exhibit not more than 110 percent of the resistance of a
shield of equal length without a joint;
(iv) The breaking strength of any section of a shield tape
containing a factory joint shall not be less than 80 percent of the
breaking strength of an adjacent section of the shield of equal length
without a joint;
(v) The reduction in thickness of the shielding material due to the
corrugating or application process shall be kept to a minimum and shall
not exceed 10 percent at any spot; and
(vi) The shielding material shall be applied in such a manner as to
enable the cable to pass the bend test as specified in paragraph (i)(1)
of this section.
(5) The dimensions of the uncoated aluminum tape shall be
0.20300.0254 mm (0.00800.0010 in.).
(6) The aluminum tape shall conform to either Alloy AA-1100-0, AA-
1145-0, or AA-1235-0 as covered in the latest edition of Aluminum
Standards and Data, issued by the Aluminum Association, except that
requirements for tensile strength are waived.
(7) The single-sided plastic coated aluminum shield shall conform
to the requirements of ASTM B 736-92a, Type I Coating, Class 1 or 2, or
Type II Coating, Class 1. The minimum thickness of the Type I Coating
shall be 0.038 mm (0.0015 in.). The minimum thickness of the Type II
Coating shall be 0.008 mm (0.0003 in.).
(8) The plastic coated aluminum shield shall be tested for
resistance to water migration by immersing a one meter (3 ft) length of
tape under a one meter (3 ft) head of water containing a soluble dye
plus 0.25 percent (%) wetting agent.
(i) After a minimum of 5 minutes, no dye shall appear between the
interface of the shield tape and the plastic coating.
(ii) The actual test method shall be acceptable to REA.
(9) The bond between the plastic coated shield and the jacket shall
conform to the following requirements:
(i) Prepare test strips approximately 200 mm (8 in.) in length.
Slit the jacket and shield longitudinally to produce 4 strips evenly
spaced and centered in 4 quadrants on the jacket circumference. One of
the strips shall be centered over the overlapped edge of the shielding
tape. The strips shall be 13 mm (0.5 in.) wide. For cable diameters
less than 19 mm (0.75 in.) make two strips evenly spaced.
(ii) Separate the shield and jacket for a sufficient distance to
allow the shield and jacket to be fitted in the upper and lower jaws of
a tensile machine. Record the maximum force required to separate the
shield and jacket to the nearest newton (pound-force). Repeat this
action for each test strip.
(iii) The force required to separate the jacket from the shield
shall not be less than 9 N (2 lbf) for any individual strip when tested
in accordance with paragraph (f)(9)(ii) of this section. The average
force for all strips of any cable shall not be less than 18 N (4 lbf).
(g) Cable jacket and extraneous material. (1) The jacket shall
provide the cable with a tough, flexible, protective covering which can
withstand stresses reasonably expected in normal installation and
service.
(2) The jacket shall be free from holes, splits, blisters, or other
imperfections and shall be as smooth and concentric as is consistent
with the best commercial practice.
(3) The raw material used for the cable jacket shall be one of the
following four types:
(i) Type PVC-55554EOXO in accordance with ASTM D 2287-81(1988);
(ii) Type PVC-65554EOXO in accordance with ASTM D 2287-81(1988);
(iii) Type PVC-55556EOXO in accordance with ASTM D 2287-81(1988);
or
(iv) Type PVC-66554EOXO in accordance with ASTM D 2287-81(1988).
(4) The jacketing material removed from or tested on the cable
shall be capable of meeting the following performance requirements:
------------------------------------------------------------------------
Jacket
Property performance
------------------------------------------------------------------------
Tensile Strength-Unaged Minimum, MPa (psi)................ 13.8 (2000)
Ultimate Elongation-Unaged Minimum, Percent (%)........... 200
Tensile Strength-Aged Minimum, % of original value........ 80
Ultimate Elongation-Aged Minimum, % of original value..... 50
Impact Failures, Maximum.................................. 2/10
------------------------------------------------------------------------
(5) Testing procedures. The procedures for testing the jacket
samples for compliance with paragraph (g)(4) of this section shall be
as follows:
(i) Tensile strength and ultimate elongation-unaged. The test shall
be performed in accordance with ASTM D 2633-82(1989), using a jaw
separation speed of 50 mm/min (2 in./min).
Note: Quality assurance testing at a jaw separation speed of 500
mm/min (20 in./min) is permissible. Failures at this rate shall be
retested at the 50 mm/min (2 in./min) rate to determine
specification compliance.
(ii) Tensile strength and ultimate elongation-aged. The test shall
be performed in accordance with paragraph (g)(5)(i) of this section
after being aged for 7 days at a temperature of 1001 deg.C
in a circulating air oven conforming to ASTM D 2436-85.
(iii) Impact. The test shall be performed in accordance with ASTM D
4565-90a using an impact force of 4 newton-meter (3 pound force-foot)
at a temperature of -101 deg.C. The cylinder shall strike
the sample at the shield overlap. A crack or split in the jacket
constitutes failure.
(6) Jacket thickness. The nominal jacket thickness shall be as
specified in the following table. The test method used shall be either
the End Sample Method (paragraph (g)(6)(i) of this section) or the
Continuous Uniformity Thickness Gauge Method (paragraph (g)(6)(ii) of
this section):
------------------------------------------------------------------------
Nominal jacket
No. of pairs thickness mm
(in.)
------------------------------------------------------------------------
25 or less............................................ 1.4 (0.055)
50.................................................... 1.5 (0.060)
100................................................... 1.7 (0.065)
200................................................... 1.9 (0.075)
300................................................... 2.2 (0.085)
400................................................... 2.4 (0.095)
600................................................... 2.9 (0.115)
800 and over.......................................... 3.3 (0.130)
------------------------------------------------------------------------
(i) End sample method. The jacket shall be capable of meeting the
following requirements:
Minimum Average Thickness--90% of nominal thickness
Minimum Thickness--70% of nominal thickness
(ii) Continuous uniformity thickness gauge method. (A) The jacket
shall be capable of meeting the following requirements:
Minimum Average Thickness--90% of nominal thickness
Minimum (Min.) Thickness--70 % of nominal thickness
Maximum (Max.) Eccentricity--55%
Eccentricity=Max. Thickness--Min. Thickness (Average Thickness) x 100
(B) Maximum and minimum thickness values. The maximum and minimum
thickness values shall be based on the average of each axial section.
(7) The color of the jacket shall be either black or dark grey in
conformance with the Munsell Color System specified in ASTM D 1535-89.
(8) There shall be no water or other contaminants in the finished
cable which would have a detrimental effect on its performance or its
useful life.
(h) Electrical requirements--(1) Mutual capacitance and
conductance. (i) The average mutual capacitance (corrected for length)
of all pairs in any reel shall not exceed the following when tested in
accordance with ASTM D 4566-90 at a frequency of 1.0 0.1
kilohertz (kHz) and a temperature of 233 deg.C:
------------------------------------------------------------------------
Mutual capacitance
-------------------------
Number of cable pairs Nanofarad/ (Nanofarad/
kilometer mile)
------------------------------------------------------------------------
12............................................ 520.1 kHz and a temperature of
233 deg.C.
(2) Pair-to-pair capacitance unbalance. The capacitance unbalance
as measured on the completed cable shall not exceed 45.3 picofarad/
kilometer (pF/km) (25 picofarad/1000 ft (pF/1000 ft)) rms when tested
in accordance with ASTM D 4566-90 at a frequency of 1.00.1
kHz and a temperature of 233 deg.C.
(3) Pair-to-ground capacitance unbalance. (i) The average
capacitance unbalance as measured on the completed cable shall not
exceed 574 pF/km (175 pF/1000 ft) when tested in accordance with ASTM D
4566-90 at a frequency of 1 0.1 kHz and a temperature of
233 deg.C.
(ii) When measuring pair-to-ground capacitance unbalance all pairs
except the pair under test are grounded to the shield except when
measuring cable containing super-units in which case all other pairs in
the same super-unit shall be grounded to the shield.
(iii) Pair-to-ground capacitance unbalance may vary directly with
the length of the cable.
(4) Crosstalk loss. (i) The rms output-to-output far-end crosstalk
loss (FEXT) measured on the completed cable in accordance with ASTM D
4566-90 at a test frequency of 150 kHz shall not be less than 68
decibel/kilometer (dB/km) (73 decibel/1000 ft (dB/1000 ft)). The rms
calculation shall be based on the combined total of all adjacent and
alternate pair combinations within the same layer and center to first
layer pair combinations.
(ii) The FEXT crosstalk loss between any pair combination of a
cable shall not be less than 58 dB/km (63 dB/1000 ft) at a frequency of
150 kHz. If the loss Ko at a frequency Fo for length Lo
is known, then Kx can be determined for any other frequency
Fx or length Lx by:
TR14JN94.000
(iii) The near-end crosstalk loss (NEXT) as measured within and
between units of a completed cable in accordance with ASTM D 4566-90 at
a frequency of 772 kHz shall not be less than the following mean minus
sigma (M-S) crosstalk requirement for any unit within the cable:
------------------------------------------------------------------------
M-S
Unit size decibel
(dB)
------------------------------------------------------------------------
Within Unit:
12 and 13 pairs............................................. 56
18 and 25 pairs............................................. 60
Between Unit:
Adjacent 13 pairs........................................... 65
Adjacent 25 pairs........................................... 66
Nonadjacent (all)........................................... 81
------------------------------------------------------------------------
Where M-S is the Mean near-end coupling loss based on the combined
total of all pair combinations, less one Standard Deviation, Sigma, of
the mean value.
(5) Insulation resistance. Each insulated conductor in each length
of completed cable, when measured with all other insulated conductors
and the shield grounded, shall have an insulation resistance of not
less than 152 megohm-kilometer (500 megohm-mile) at
201 deg.C. The measurement shall be made in accordance with
the procedures of ASTM D 4566-90.
(6) High voltage test. (i) In each length of completed cable, the
dielectric strength of the insulation between conductors shall be
tested in accordance with ASTM D 4566-90 and shall withstand, for 3
seconds, a direct current (dc) potential whose value is not less than:
(A) 3.6 kilovolts for 22-gauge conductors; or
(B) 3.0 kilovolts for 24-gauge conductors.
(ii) In each length of completed cable, the dielectric strength
between the shield and all conductors in the core shall be tested in
accordance with ASTM D 4566-90 and shall withstand, for 3 seconds, a dc
potential whose value is not less than 10 kilovolts.
(7) Conductor resistance. The dc resistance of any conductor shall
be measured in the completed cable in accordance with ASTM D 4566-90
and shall not exceed the following values when measured at or corrected
to a temperature of 201 deg.C:
------------------------------------------------------------------------
Maximum resistance
AWG ---------------------------------------------------------------
ohms/kilometer (ohms/1000 ft)
------------------------------------------------------------------------
22...... 60.7 (18.5)
24...... 95.1 (29.0)
------------------------------------------------------------------------
(8) Resistance unbalance. (i) The difference in dc resistance
between the two conductors of a pair in the completed cable shall not
exceed the values listed in this paragraph when measured in accordance
with the procedures of ASTM D 4566-90:
------------------------------------------------------------------------
Resistance unbalance Maximum for any reel
AWG ---------------------------------------------------------------
Average percent Individual pair percent
------------------------------------------------------------------------
22...... 1.5 4.0
24...... 1.5 5.0
------------------------------------------------------------------------
(ii) The resistance unbalance between tip and ring conductors shall
be random with respect to the direction of unbalance. That is, the
resistance of the tip conductors shall not be consistently higher with
respect to the ring conductors and vice versa.
(9) Electrical variations. (i) Pairs in each length of cable having
either a ground, cross, short, or open circuit condition shall not be
permitted.
(ii) The maximum number of pairs in a cable which may vary as
specified in paragraph (h)(9)(iii) of this section from the electrical
parameters given in this section are listed in this paragraph. These
pairs may be excluded from the arithmetic calculation:
------------------------------------------------------------------------
Maximum No.
of pairs
with
Nominal pair count allowable
electrical
variation
------------------------------------------------------------------------
12-100..................................................... 1
101-300.................................................... 2
301-400.................................................... 3
401-600.................................................... 4
601 and above.............................................. 6
------------------------------------------------------------------------
(iii) Parameter variations--(A) Capacitance unbalance-to-ground. If
the cable fails either the maximum individual pair or average
capacitance unbalance-to-ground requirement and all individual pairs
are 3280 pF/km (1000 pF/1000 ft) or less the number of pairs specified
in paragraph (h)(9)(ii) of this section may be eliminated from the
average and maximum individual calculations.
(B) Resistance unbalance. Individual pair of not more than 7
percent for all gauges.
(C) Far end crosstalk. Individual pair combination of not less than
52 dB/km (57 dB/1000 ft).
Note: REA recognizes that in large pair count cables (600 pair
and above) a cross, short, or open circuit condition occasionally
may develop in a pair which does not affect the performance of the
other cable pairs. In these circumstances rejection of the entire
cable may be economically unsound or repairs may be impractical. In
such circumstances the manufacturer may desire to negotiate with the
customer for acceptance of the cable. No more than 0.5 percent of
the pairs may be involved.
(i) Mechanical requirements--(1) Cable cold bend test. The
completed cable shall be capable of meeting the requirements of ASTM D
4565-90a after conditioning at -20 2 deg.C except the
mandrel diameters shall be as specified below:
------------------------------------------------------------------------
Mandrel
Cable outside diameter diameter
------------------------------------------------------------------------
<40 mm="" (1.5="" in.)............................................="" 15x="">40 mm (1.5 in.).................................. 20x
------------------------------------------------------------------------
(2) Cable flame test. The completed cable shall be capable of
meeting a maximum flame height of 3.7 m (12.0 ft) when tested in
accordance with Underwriters Laboratories (UL) 1666 dated January 22,
1991.
(3) Cable listing. All cables manufactured to the specification of
this section at a minimum shall be listed as Communication Riser Cable
(Type CMR) in accordance with Sections 800-50 and 800-51(b) of the 1993
National Electrical Code.
(j) Sheath slitting cord (optional). (1) Sheath slitting cords may
be used in the cable structure at the option of the manufacturer.
(2) When a sheath slitting cord is used it shall be nonhygroscopic
and nonwicking, continuous throughout a length of cable, and of
sufficient strength to open the sheath without breaking the cord.
(3) Sheath slitting cords shall be capable of consistently slitting
the jacket and/or shield for a continuous length of 0.6 m (2 ft) when
tested in accordance with the procedure specified in Appendix B of this
section.
(k) Identification marker and length marker. (1) Each length of
cable shall be permanently identified as to manufacturer and year of
manufacture.
(2) The number of conductor pairs and their gauge size shall be
marked on the jacket.
(3) The marking shall be printed on the jacket at regular intervals
of not more than 1.5 m (5 ft).
(4) An alternative method of marking may be used if accepted by REA
prior to its use.
(5) The completed cable shall have sequentially numbered length
markers in FEET OR METERS at regular intervals of not more than 1.5 m
(5 ft) along the outside of the jacket.
(6) The method of length marking shall be such that for any single
length of cable, continuous sequential numbering shall be employed.
(7) The numbers shall be dimensioned and spaced to produce good
legibility and shall be approximately 3 mm (0.125 in.) in height. An
occasional illegible marking is permissible if there is a legible
marking located not more than 1.5 m (5 ft) from it.
(8) The method of marking shall be by means of suitable surface
markings producing a clear, distinguishable, contrasting marking
acceptable to REA. Where direct or transverse printing is employed, the
characters should be indented to produce greater durability of marking.
Any other method of length marking shall be acceptable to REA as
producing a marker suitable for the field. Size, shape and spacing of
numbers, durability, and overall legibility of the marker shall be
considered in acceptance of the method.
(9) The accuracy of the length marking shall be such that the
actual length of any cable section is never less than the length
indicated by the marking and never more than one percent greater than
the length indicated by the marking.
(10) The color of the initial marking for a black colored jacket
shall be either white or silver. The color of the initial marking for a
dark grey colored jacket shall be either red or black. If the initial
marking of the black colored jacket fails to meet the requirements of
the preceding paragraphs, it will be permissible to either remove the
defective marking and re-mark with the white or silver color or leave
the defective marking on the cable and re-mark with yellow. If the
initial marking of the dark grey colored jacket fails to meet the
requirements of the preceding paragraphs, it will be permissible to
either remove the defective marking and re-mark with the red or black
color or leave the defective marking on the cable and re-mark with
yellow. No further re-marking is permitted. Any re-marking shall be on
a different portion of the cable circumference than any existing
marking when possible and have a numbering sequence differing from any
other existing marking by at least 5,000.
(11) Any reel of cable which contains more than one set of
sequential markings shall be labeled to indicate the color and sequence
of marking to be used. The labeling shall be applied to the reel and
also to the cable.
(l) Preconnectorized cable (optional). (1) At the option of the
manufacturer and upon request by the purchaser, cables 100 pairs and
larger may be factory terminated in 25 pair splicing modules.
(2) The splicing modules shall meet the requirements of REA
Bulletin 345-54, PE-52, REA Specification for Telephone Cable Splicing
Connectors (Incorporated by Reference at Sec. 1755.97), and be accepted
by REA prior to their use.
(m) Acceptance testing and extent of testing. (1) The tests
described in Appendix A of this section are intended for acceptance of
cable designs and major modifications of accepted designs. REA decides
what constitutes a major modification. These tests are intended to show
the inherent capability of the manufacturer to produce cable products
having long life and stability.
(2) For initial acceptance, the manufacturer shall submit:
(i) An original signature certification that the product fully
complies with each section of the specification;
(ii) Qualification Test Data, per Appendix A of this section;
(iii) To periodic plant inspections;
(iv) A certification that the product does or does not comply with
the domestic origin manufacturing provisions of the ``Buy American''
requirements of the Rural Electrification Act of 1938 (7 U.S.C. 901 et
seq.);
(v) Written user testimonials concerning performance of the
product; and
(vi) Other nonproprietary data deemed necessary by the Chief,
Outside Plant Branch (Telephone).
(3) For requalification acceptance, the manufacturer shall submit
an original signature certification that the product fully complies
with each section of the specification, excluding the Qualification
Section, and a certification that the product does or does not comply
with the domestic origin manufacturing provisions of the ``Buy
American'' requirements of the Rural Electrification Act of 1938 (7
U.S.C. 901 et seq.) for acceptance by June 30 every three years. The
required data and certification shall have been gathered within 90 days
of the submission.
(4) Initial and requalification acceptance requests should be
addressed to: Chairman, Technical Standards Committee ``A''
(Telephone), Telecommunications Standards Division, Rural
Electrification Administration, Washington, DC 20250-1500.
(5) Tests on 100 percent of completed cable. (i) The shield of each
length of cable shall be tested for continuity using the procedures of
ASTM D 4566-90.
(ii) Dielectric strength between all conductors and the shield
shall be tested to determine freedom from grounds in accordance with
paragraph (h)(6)(ii) of this section.
(iii) Each conductor in the completed cable shall be tested for
continuity using the procedures of ASTM D 4566-90.
(iv) Dielectric strength between conductors shall be tested to
ensure freedom from shorts and crosses in accordance with paragraph
(h)(6)(i) of this section.
(v) Each conductor in the completed preconnectorized cable shall be
tested for continuity.
(vi) Each length of completed preconnectorized cable shall be
tested for split pairs.
(vii) The average mutual capacitance shall be measured on all
cables. If the average mutual capacitance for the first 100 pairs
tested from randomly selected groups is between 50 and 53 nF/km (80 to
85 nF/mile), the remainder of the pairs need not to be tested on the
100 percent basis. (See paragraph (h)(1) of this section).
(6) Capability tests. Tests on a quality assurance basis shall be
made as frequently as is required for each manufacturer to determine
and maintain compliance with:
(i) Performance requirements for conductor insulation and jacket
material;
(ii) Bonding properties of coated or laminated shielding materials;
(iii) Sequential marking and lettering;
(iv) Capacitance unbalance and crosstalk;
(v) Insulation resistance;
(vi) Conductor resistance and resistance unbalance;
(vii) Cable cold bend and cable flame tests; and
(viii) Mutual conductance.
(n) Summary of records of electrical and physical tests. (1) Each
manufacturer shall maintain a suitable summary of records for a period
of at least 3 years for all electrical and physical tests required on
completed cable by this section as set forth in paragraphs (m)(5) and
(m)(6) of this section. The test data for a particular reel shall be in
a form that it may be readily available to the purchaser or to REA upon
request.
(2) Measurements and computed values shall be rounded off to the
number of places of figures specified for the requirement according to
ASTM E 29-90.
(o) Manufacturing irregularities. (1) Repairs to the shield are not
permitted in cable supplied to the end user under this section.
(2) No repairs or defects in the jacket are allowed.
(p) Preparation for shipment. (1) The cable shall be shipped on
reels unless otherwise specified or agreed to by the purchaser. The
diameter of the drum shall be large enough to prevent damage to the
cable from reeling or unreeling. The reels shall be substantial and so
constructed as to prevent damage to the cable during shipment and
handling.
(2) A waterproof corrugated board or other means of protection
acceptable to REA shall be applied to the reel and shall be suitably
secured in place to prevent damage to the cable during storage and
shipment.
(3) The outer end of the cable shall be securely fastened to the
reel head so as to prevent the cable from becoming loose in transit.
The inner end of the cable shall be securely fastened in such a way as
to make it readily available if required for electrical testing.
Spikes, staples, or other fastening devices which penetrate the cable
jacket shall not be used. The method of fastening the cable ends shall
be accepted by REA prior to it being used.
(4) Each length of cable shall be wound on a separate reel unless
otherwise specified or agreed to by the purchaser.
(5) The arbor hole shall admit a spindle 63 mm (2.5 in.) in
diameter without binding. Steel arbor hole liners may be used but shall
be acceptable to REA prior to their use.
(6) Each reel shall be plainly marked to indicate the direction in
which it should be rolled to prevent loosening of the cable on the
reel.
(7) Each reel shall be stenciled or labeled on either one or both
sides with the name of the manufacturer, year of manufacture, actual
shipping length, an inner and outer end sequential length marking,
description of the cable, reel number and the REA cable designation:
Cable Designation
CT
Cable Construction
Pair Count
Conductor Gauge
A = Coated Aluminum Shield
P = Preconnectorized Cable
Example: CTAP 100-22
Terminating Cable, Coated Aluminum Shield, Preconnectorized, 100
pairs, 22 AWG.
(8) When preconnectorized cable is shipped, the splicing modules
shall be protected to prevent damage during shipment and handling. The
protection method shall be acceptable to REA prior to its use.
Appendix A to 7 CFR 1755.870--Qualification Test Methods
(I) The test procedures described in this appendix are for
qualification of initial designs and major modifications of accepted
designs. Included in paragraph (V) of this appendix are suggested
formats that may be used in submitting test results to REA.
(II) Sample Selection and Preparation. (1) All testing shall be
performed on lengths removed sequentially from the same 25 pair, 22
gauge jacketed cable. This cable shall not have been exposed to
temperatures in excess of 38 deg.C since its initial cool down
after sheathing. The lengths specified are minimum lengths and if
desirable from a laboratory testing standpoint longer lengths may be
used.
(a) Length A shall be 12 0.2 meters (40
0.5 feet) long. Prepare the test sample by removing the
jacket, shield, and core wrap for a sufficient distance on both ends
to allow the insulated conductors to be flared out. Remove
sufficient conductor insulation so that appropriate electrical test
connections can be made at both ends. Coil the sample with a
diameter of 15 to 20 times its sheath diameter. Two lengths are
required.
(b) Length B shall be 300 millimeters (1 foot) long. Three
lengths are required.
(c) Length C shall be 3 meters (10 feet) long and shall be
maintained at 23 3 deg.C for the duration of the test.
Two lengths are required.
(2) Data Reference Temperature. Unless otherwise specified, all
measurements shall be made at 23 3 deg.C.
(III) Environmental Tests--(1) Heat Aging Test--(a) Test
Samples. Place one sample each of lengths A and B in an oven or
environmental chamber. The ends of sample A shall exit from the
chamber or oven for electrical tests. Securely seal the oven exit
holes.
(b) Sequence of Tests. Sample B referenced in paragraph
(III)(1)(a) of this appendix shall be subjected to the insulation
compression test outlined in paragraph (III)(2) of this appendix.
(c) Initial Measurements. (i) For sample A, measure the open
circuit capacitance and conductance for each odd pair at 1, 150, and
772 kilohertz after conditioning the sample at the data reference
temperature for 24 hours. Calculate the average and standard
deviation for the data of the 13 pairs on a per kilometer (per mile)
basis.
(ii) Record on suggested formats in paragraph (V) of this
appendix or on other easily readable formats.
(d) Heat Conditioning. (i) Immediately after completing the
initial measurements, condition the sample for 14 days at a
temperature of 65 2 deg.C.
(ii) At the end of this period. Measure and calculate the
parameters given in paragraph (III)(1)(c) of this appendix. Record
on suggested formats in paragraph (V) of this appendix or on other
easily readable formats.
(e) Overall Electrical Deviation. (i) Calculate the percent
change in all average parameters between the final parameters after
conditioning with the initial parameters in paragraph (III)(1)(c) of
this appendix.
(ii) The stability of the electrical parameters after completion
of this test shall be within the following prescribed limits:
(A) Capacitance. The average mutual capacitance shall be within
10 percent of its original value;
(B) The change in average mutual capacitance shall be less than
10 percent over the frequency range of 1 to 150 kilohertz; and
(C) Conductance. The average mutual conductance shall not exceed
3.7 micromhos/kilometer (6 micromhos/mile) at a frequency of 1
kilohertz.
(2) Insulation Compression Test--(a) Test Sample B. Remove
jacket, shield, and core wrap being careful not to damage the
conductor insulation. Remove one pair from the core and carefully
separate and straighten the insulated conductors. Retwist the two
insulated conductors together under sufficient tension to form 10
evenly spaced 360 degree twists in a length of 100 millimeters (4
inches).
(b) Sample Testing. Center the mid 50 millimeters (2 inches) of
the twisted pair between two smooth rigid parallel metal plates
measuring 50 millimeters (2 inches) in length or diameter. Apply a
1.5 volt direct current potential between the conductors, using a
light or buzzer to indicate electrical contact between the
conductors. Apply a constant load of 67 newtons (15 pound-force) on
the sample for one minute and monitor for evidence of contact
between the conductors. Record results on suggested formats in
paragraph (V) of this appendix or on other easily readable formats.
(3) Temperature Cycling. (a) Repeat paragraphs (III)(1)(a)
through (III)(1)(c)(ii) of this appendix for a separate set of
samples A and B which have not been subjected to prior environmental
conditioning.
(b) Immediately after completing the measurements, subject the
test samples to 10 cycles of temperature between -40 deg.C and +60
deg.C. The test samples shall be held at each temperature extreme
for a minimum of 1.5 hours during each cycle of temperature. The air
within the temperature cycling chamber shall be circulated
throughout the duration of the cycling.
(c) Repeat paragraphs (III)(1)(d)(ii) through (III)(2)(b) of
this appendix.
(IV) Control Sample--(1) Test Samples. One length of sample B
shall have been maintained at 23 3 deg.C for at least
48 hours before the testing.
(2) Repeat paragraphs (III)(2) through (III)(2)(b) of this
appendix.
(3) Surge Test. (a) One length of sample C shall be used to
measure the breakdown between conductors while the other length of C
shall be used to measure core to shield breakdown.
(b) The samples shall be capable of withstanding, without
damage, a single surge voltage of 20 kilovolts peak between
conductors, and 35 kilovolts peak between conductors and the shield
as hereinafter described. The surge voltage shall be developed from
a capacitor discharge through a forming resistor connected in
parallel with the dielectric of the test sample. The surge generator
constants shall be such as to produce a surge of 1.5 x 40
microseconds wave shape.
(c) The shape of the generated wave shall be determined at a
reduced voltage by connecting an oscilloscope across the forming
resistor with the cable sample connected in parallel with the
forming resistor. The capacitor bank is charged to the test voltage
and then discharged through the forming resistor and test sample.
The test sample shall be considered to have passed the test if there
is no distinct change in the wave shape obtained with the initial
reduced voltage compared to that obtained after the application of
the test voltage.
(V) The following suggested formats may be used in submitting
the test results to REA:
Environmental Conditioning ____________________
Frequency 1 Kilohertz
------------------------------------------------------------------------
Capacitance nF/km P(nF/ Conductance micromhos/km
mile) (micromhos/mile)
Pair No. ---------------------------------------------------
Initial Final Initial Final
------------------------------------------------------------------------
1................... ........... ........... ........... ...........
3................... ........... ........... ........... ...........
5................... ........... ........... ........... ...........
7................... ........... ........... ........... ...........
9................... ........... ........... ........... ...........
11.................. ........... ........... ........... ...........
13.................. ........... ........... ........... ...........
15.................. ........... ........... ........... ...........
17.................. ........... ........... ........... ...........
19.................. ........... ........... ........... ...........
21.................. ........... ........... ........... ...........
23.................. ........... ........... ........... ...........
25.................. ........... ........... ........... ...........
Average x.8......... ........... ........... ........... ...........
Overall Percent
Difference in
Average x.8..... ........... ........... ........... ...........
------------------------------------------------------------------------
Environmental Conditioning ____________________
Frequency 150 Kilohertz
------------------------------------------------------------------------
Capacitance nF/km P(nF/ Conductance micromhos/km
mile) (micromhos/mile)
Pair No. ---------------------------------------------------
Initial Final Initial Final
------------------------------------------------------------------------
1................... ........... ........... ........... ...........
3................... ........... ........... ........... ...........
5................... ........... ........... ........... ...........
7................... ........... ........... ........... ...........
9................... ........... ........... ........... ...........
11.................. ........... ........... ........... ...........
13.................. ........... ........... ........... ...........
15.................. ........... ........... ........... ...........
17.................. ........... ........... ........... ...........
19.................. ........... ........... ........... ...........
21.................. ........... ........... ........... ...........
23.................. ........... ........... ........... ...........
25.................. ........... ........... ........... ...........
Average x.8......... ........... ........... ........... ...........
Overall Percent
Difference in
Average x.8.... ........... ........... ........... ...........
------------------------------------------------------------------------
Environmental Conditioning ____________________
Frequency 772 Kilohertz
----------------------------------------------------------------------------------------------------------------
Capacitance nF/km P(nF/ Conductance micromhos/km
mile) (micromhos/mile)
Pair No. ---------------------------------------------------
Initial Final Initial Final
----------------------------------------------------------------------------------------------------------------
1........................................................... ........... ........... ........... ...........
3........................................................... ........... ........... ........... ...........
5........................................................... ........... ........... ........... ...........
7........................................................... ........... ........... ........... ...........
9........................................................... ........... ........... ........... ...........
11.......................................................... ........... ........... ........... ...........
13.......................................................... ........... ........... ........... ...........
15.......................................................... ........... ........... ........... ...........
17.......................................................... ........... ........... ........... ...........
19.......................................................... ........... ........... ........... ...........
21.......................................................... ........... ........... ........... ...........
23.......................................................... ........... ........... ........... ...........
25.......................................................... ........... ........... ........... ...........
Average x.8................................................. ........... ........... ........... ...........
Overall Percent Difference in...........................
Average x.8............................................. ........... ........... ........... ...........
----------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------
Failures
------------------------------------------------------------------------
Insulation Compression:
Control..................................................... ........
Heat Age.................................................... ........
Temperature Cycling......................................... ........
Surge Test (kilovolts):
Conductor-to-Conductor...................................... ........
Shield-to-Conductors........................................ ........
------------------------------------------------------------------------
Appendix B to 7 CFR 1755.870--Sheath Slitting Cord Qualification
(I) This test procedure described in this appendix is for
qualification of initial and subsequent changes in sheath slitting
cords.
(II) Sample selection. All testing shall be performed on two 1.2
m (4 ft) lengths of cable removed sequentially from the same 25
pair, 22 gauge jacketed cable. This cable shall not have been
exposed to temperatures in excess of 38 deg.C since its initial
cool down after sheathing.
(III) Test procedure. (1) Using a suitable tool, expose enough
of the sheath slitting cord to permit grasping with needle nose
pliers.
(2) The prepared test specimens shall be maintained at a
temperature of 23 1 deg.C for at least 4 hours
immediately prior to and during the test.
(3) Wrap the sheath slitting cord around the plier jaws to
ensure a good grip.
(4) Grasp and hold the cable in a convenient position while
gently and firmly pulling the sheath slitting cord longitudinally in
the direction away from the cable end. The angle of pull may vary to
any convenient and functional degree. A small starting notch is
permissible.
(5) The sheath slitting cord is considered acceptable if the
cord can slit the jacket and/or shield for a continuous length of
0.6 m P(2 ft) without breaking the cord.
Dated: June 2, 1994.
Bob J. Nash,
Under Secretary, Small Community and Rural Development.
[FR Doc. 94-14338 Filed 6-13-94; 8:45 am]
BILLING CODE 3410-15-P
