SECTION 26 12 10 – CABLES, MEDIUM VOLTAGE
PART 1 - GENERAL
1.01
1.02
DESCRIPTION:
A.
General provisions and other electrical systems are specified in other Sections of Division 26.
B.
This Section covers single-conductor, insulated, thermoplastic-jacketed power cables.
C.
Commissioning is specified in Section 26 00 90, Commissioning. This Section includes responsibilities and
obligations in support of the commissioning process specified therein.
QUALITY ASSURANCE:
A.
B.
Conform to the following:
1.
AEIC CS8-2007.
2.
NECA/MACSB 600-2003.
3.
NEMA WC 74-2006/ICEA S-93-639.
4.
NFPA 70-2008.
5.
UL 1072-2006.
Experience Qualifications:
1.
The Contractor directly responsible for receiving, handling and installation of medium voltage cable
shall have had at least 3 years experience in performing similar work in underground ductbank and
manhole systems. Submit references including project names, dates and contact person names and
telephone numbers for at least 3 similar projects within the past 3 years. Projects used as references
shall include the installation of medium voltage cable of the 5 kV class or higher, involving duct banks
and manholes.
2.
The Contractor shall submit proof that each cable splicer has had at least 3 years experience in
splicing EPR cables rated in the 15 kV voltage class. This proof is required before any splicing may
proceed and shall consist of at least 3 references with contact names and telephone numbers.
3.
The service and testing company shall be one which has been in the business of testing medium
voltage cables for at least 3 years, and shall not be a part of any business entity responsible for the
supply and installing medium voltage cable under this contract. Test results shall be certified by a
licensed professional electrical engineer employed by the testing company. The engineer shall
interpret the results and shall sign each test report. Test equipment used shall have been calibrated
within the 12 month period immediately preceding the test date. Certification of calibration within this
time period is required and shall be furnished with the test reports. Test reports furnished without
this certification or tests made with equipment without the required certification are invalid and will not
be accepted.
PART 2 - PRODUCTS
2.01
GENERAL:
A.
2.02
Cables shall be capable of operating continuously at a conductor temperature of 105°C for normal operation,
140°C for emergency overload conditions, and 250°C for short circuit conditions, and shall be rated at 5000
V, 133% insulation level (ungrounded neutral).
CONDUCTORS:
A.
Conductors shall be soft or annealed Class B compressed concentric stranded copper in accordance with
ASTM B3-2001 (2007) and B8-2004, and NEMA WC 74-2006/ICEA S-93-639.
©MBAJ ARCHITECTURE #1007 / ETB #0905
26 12 10 - 1
Advantage Valley Advanced Technology Center
WV-CTCS
SECTION 26 12 10 – CABLES, MEDIUM VOLTAGE
2.03
CONDUCTOR SHIELDING:
A.
2.04
INSULATION:
A.
2.05
Cables shall be identified by surface printing of the jacket indicating manufacturer, size, insulation type,
voltage rating, and UL designations.
MANUFACTURER:
A.
2.09
Cables shall be provided with jackets of black polyvinyl chloride compound. The average thickness shall be
in accordance with NEMA WC 74-2006/ICEA S-93-639.
MANUFACTURER'S IDENTIFICATION:
A.
2.08
Insulation shall be covered with an extruded layer of semiconducting thermosetting material which shall be
identified as being semiconducting. Over this layer shall be applied a helical, lapped 0.005" bare copper
tape, with a minimum 25% overlap.
JACKETS:
A.
2.07
Insulation shall be ethylene propylene rubber. The minimum spot thickness shall be not less than 90% of
the average thickness.
SHIELDING:
A.
2.06
Conductors shall be shielded with an extruded semiconducting layer over the conductor, applied in tandem
with and firmly bonded to the insulation.
Aetna MV-105, General Cable MV-105, Okonite MV-105, Pirelli MV-105, or Southwire MV-105 series.
ACCESSORIES:
A.
Modular Splices:
1.
Modular splices shall be separable, submersible, dead-break, rated 15 kV, minimum 95 kV BIL,
600 A. Modular splices shall be capable of splicing 2 cables and shall allow for easy disconnect and
re-use. Provide necessary tools required to separate and reconnect the modular splices and taps
and turn over to the Owner's representative at the completion of the Project.
a.
B.
Terminations (at switchgear):
1.
Terminations shall be class 1 type conforming to the requirements of IEEE 48-2009. Stress cones
shall be single-piece, slip-on devices designed for use in switchgear enclosures. Stress cones shall
be rated 15 kV (line-to-ground) and have dry withstand voltage rating of 50 kV at 60 Hz for 1 min and
35 kV at 60 Hz for 6 h, and corona extinction voltage level of 13 kV.
a.
2.
3.
Manufacturer: 3M 7690-S series for outdoor locations and 3M-7620-T series for indoor
locations, or Pirelli Elaspeed.
Grounding devices shall provide a watertight ground connection for the drain shield.
a.
C.
Manufacturer: 3M 5815-S including taps and applicable accessory kits, Cooper 700-22
series, Elastimold 600 series, or Hubbell Power Systems DTP series.
Manufacturer: 3M.
Provide mounting hardware, covers, connectors, shield termination and grounding for terminations.
Terminations (at pad-mounted transformers):
1.
Cables shall be terminated using a modular elbow type 600 A deadbreak termination system with a
loadbreak reducing tap plug and a metal oxide varistor elbow surge arrestor.
©MBAJ ARCHITECTURE #1007 / ETB #0905
26 12 10 - 2
Advantage Valley Advanced Technology Center
WV-CTCS
SECTION 26 12 10 – CABLES, MEDIUM VOLTAGE
2.
D.
Manufacturer:
series.
Cooper T-OP II series, Elastimold 600 series, or Hubbell Power Systems LRTP
Fireproof tape: flexible, conformable, polymeric elastomer fireproof type, designed for exposure to oil, water,
gases, salt water, sewage, and fungus. Tape shall not damage cable jackets or insulation.
1.
Manufacturer: 3M, Permacel, Plymouth Rubber 53 PlyArc, or Scotch 77.
PART 3 - EXECUTION
3.01
3.02
INSTALLATION:
A.
Install medium voltage cable and terminations in accordance with the manufacturer's written instructions.
B.
Ground cable shield at each termination.
C.
Medium Voltage Cable Identification:
1.
Identify cables as to phase and circuit at each accessible location. Identification shall be
accomplished by means of brass tags permanently affixed to cable embossed in letters no less than
0.5".
2.
Arrange tags such that they can be read without moving cables.
D.
Pull cables in continuous lengths unless splices are specified herein or are indicated on the Drawings.
E.
Provide cable lengths with liberal allowances for slack for terminating. If pulling grips are used, sufficient
excess cable shall be allowed so that damage due to the pulling grips can be removed prior to terminating.
Cable shall not be pulled with the ends open. Where cable requires more than one pull, lay down new 6 mil
PVC plastic sheathing on the ground in the lay down area. The cable shall not be dragged across the
surface, but shall be laid on the surface between pulls. Cable ends shall be moisture proofed at all times
until terminations are installed.
F.
Exercise care in cable handling and installation to prevent deformation, abrasion, and other damaging
effects.
G.
Cables shall not be bent more sharply than the greater of the manufacturer's recommendation or 12 times
the cable outside diameter. Care shall be exercised to prevent damage to the cable sheath, conductor or
insulation due to nicking, excess pulling tension, or deformation. Where cables are bent at a smaller radius
than that specified, the affected cables shall be replaced at no additional expense to the Owner.
H.
Where cables are to be pulled through manholes or enclosures, sheaves of appropriate radius shall be used
to prevent bending the cables more sharply than the minimum specified by the cable manufacturer.
Conveyor sheave assemblies having at least one roller for each 20° of bend are acceptable.
I.
Medium voltage cables shall be pulled with manufactured cable pulling eyes attached to the conductors.
Basket grips shall not be used.
J.
Where mishandling occurs or where evidence of mishandling is found, the affected cables shall be replaced
at no additional expense to the Owner.
TERMINATIONS, SPLICES AND CONNECTIONS:
A.
Terminations, splices and connections shall be made with connectors and apparatus bushings.
B.
Equip unused terminations and connections with waterproof dead-end covers.
C.
Feeder cables to buildings shall be spliced in the last manhole closest to the building which they serve,
using modular type splices. Straight inline splices shall be used in other manholes where needed.
D.
Cables splices shall be grounded and sealed.
E.
Cable shields shall be grounded at each termination through the use of termination kits using manufacturer's
recommended fittings, materials, and grounding conductors. Provide ground lugs in equipment and make
©MBAJ ARCHITECTURE #1007 / ETB #0905
26 12 10 - 3
Advantage Valley Advanced Technology Center
WV-CTCS
SECTION 26 12 10 – CABLES, MEDIUM VOLTAGE
connections to grounding. In switchgear, make connections to ground bus. In manholes, make connections
to grounding conductor around inside perimeter of each manhole.
3.03
TESTS:
A.
B.
Factory Testing:
1.
The cable manufacturer shall perform nondestructive factory tests on cable in accordance with ICEA
standards.
2.
Factory certified tests shall be included as part of the conductor submittal.
Field Testing:
1.
A certified third party testing firm shall perform the DC high potential testing.
2.
High potential tests on medium voltage cables shall be performed as follows:
a.
New conductors shall be tested after conductors have been installed and terminated.
b.
Existing conductors shall not be high potential tested after installation and termination.
c.
When new conductors are spliced to existing conductors testing shall be performed once
when the new conductors are installed and terminated; after the new conductors are spliced
to the existing conductors, only 500 V megohm meter/continuity checks shall be performed.
d.
New and existing conductors shall be disconnected from equipment prior to testing and
reconnected afterward.
e.
Tests shall be conducted as recommended in IEEE 576-2000 for the voltage rating of the
cable and installation.
f.
The DC high potential voltage shall be applied in no less than 5 equal steps or increments
until the maximum test voltage is achieved. No increment shall exceed the test voltage level
of the conductors as specified herein. The voltage at each intermediate step shall be held for
at least 1 min, and the DC leakage current shall be recorded at each level after a constant
stabilization time consistent with system charging current.
g.
Record readings of leakage current 30 s and 1 min after achieving test voltage, and at 1 min
intervals thereafter until the test duration is achieved.
h.
The maximum test voltage shall be maintained for no less than 10 min. In no event shall the
test voltage be applied for more than 15 min.
i.
Record results of test in tabular form and in plots of current versus time for incremental
voltages, and current versus time at maximum voltage.
j.
Adequate means shall be taken to ensure safety during the tests and safety instructions of the
test operator shall be carried out.
k.
If a cable fails, the fault shall be located, and all cables in that conduit between the nearest
pulling points on each side of the failure shall be withdrawn. If, in the opinion of the Owner,
the other cables in the same conduit have not been damaged, they may be reinstalled, but the
cable which failed shall be replaced by new cable. After the replacement of the faulted cable,
and any other damaged cables, all cables of the circuit in that conduit shall be retested.
l.
During the period of warranty any failure in primary cable, terminations or splices shall require
immediate correction. In the event of a failure creating interruption in electrical service,
furnish and install labor and materials for temporary services to get the electrical system back
in service. Work shall begin immediately upon notification of a failure, regardless of time.
©MBAJ ARCHITECTURE #1007 / ETB #0905
26 12 10 - 4
Advantage Valley Advanced Technology Center
WV-CTCS
SECTION 26 12 10 – CABLES, MEDIUM VOLTAGE
3.
C.
3.04
Submit certified test results of each test on the feeder conductor installed with operations and
maintenance manuals.
Provide temporary splicing work (caps) necessary to prepare the cable for high potential testing.
CABLE INSTALLATION IN MANHOLES:
A.
Cables shall be secured to cable support arms in manholes with nonconductive cable ties. Cables shall be
tagged with brass valve tags stamped with minimum 0.375" lettering. Feeders shall be labeled similar to:
5 kV feeder
From
To
Supplying
3.05
DSG2B-16
MH-21C
MH-21A
Bldg. 21
B.
Label cables as described above except that tags at above grade equipment shall be made with nonmetallic UV-resistant tags and ties. Lettering shall be made with a permanent black marker.
C.
Pump and clean existing manholes as needed to accomplish the work and as needed to allow inspection.
Existing manholes shall be provided with additional racks as needed for the new cables.
D.
Where cables are spliced in manholes, rack cables fully across manhole walls plus additional length to
continue to ductbank entrances. Install splices at locations within manholes to permit future replacement of
splices by cutting and re-racking the affected cable. Where cables pass through manholes unspliced, rack
along the longest route through the manhole. Cables shall not enter and exit through adjacent ductbank
entrances without looping the manhole.
FIREPROOFING:
A.
Medium voltage cables and conductors in manholes shall be fireproofed for their entire length within a
manhole. Fireproofing shall extend at least 1" into any duct.
B.
Fireproof tape shall be wrapped tightly around each cable spirally in one-half lapped wrapping or in 2 buttjointed wrappings with the second wrapping covering the joints of the first.
END OF SECTION 26 12 10
©MBAJ ARCHITECTURE #1007 / ETB #0905
26 12 10 - 5
Advantage Valley Advanced Technology Center
WV-CTCS