SECTION 682 - ELECTRICAL DISTRIBUTION SYSTEM
682.01 Description. In additional to the requirements set forth in Section 681, the
electrical distribution system generally cons ists of the secondary electrical service, grounding and bonding system, secondary distribution and secondary power controller. The secondary electrical service shall be 480 volts, 1 phase, 3-wire, 60 HZ, unless indicated otherwise on the plans. The overhead service entrance shall have five (5) feet of tail-wire extension from the service entrance cap for connection to the Utility Company's overhead transformer service facilities. An underground service entrance shall consist of conduit and wire placed, after coordination with the serving utility, in a manner to connect the secondary power controller with the ground mounted transformer. The system will be metered as per serving utility company's requirements. Bonding and grounding of all electrical service equipment enclosures and ground terminals shall be as shown on the plans and/or in accordance with Article 250 of the National Electrical Code. The secondary distribution shall consist of furnishing, installing, erecting and laying electrical branch circuits. All branch circuits shall be buried underground except where shown otherwise on the plans. Branch circuits shall consist of conduit, conductors, connectors, and all hardware necessary to complete the work. Pull boxes and junction boxes may be both underground and/or structure mounted. The secondary power controller shall consist of a lighting controller for control of roadway lighting, enclosure, conduit with fittings, wire, devices, ground rods, photocell, and miscellaneous hardware. The controller shall have a dead front behind outer doors with only breaker handles, hand-off automatic sel ector switch and receptacle exposed. All controllers shall be labeled with a phenolic engraved label having 1/4-inch white letters on a black background. Example: "SPC#l".
682.02 Materials.
682.02.1 Secondary Distribution. The materials used in this construction shall meet the
requirements of Subsection 723.02.
682.02.2 Secondary Power Controller . The materials used in this construction shall
meet the requirements of Subsection 723.03.
682.03 Construction Requirements.
682.03.1 Grounding and Bonding System. Where conduit enters an enclosure, a
bonding type bushing shall be used on all conduits with #6 AWG copper bonding conductors bonded to all conduits thence to equipment enclosure or ground bus. The green equipment grounding terminal of all grounding type equipment shall be bonded to its equipment ground conductor with a properly sized green bonding conductor. One (1) green equipment grounding conductor shall be pulled into all raceways, sized the same as the branch circuit conductors, or as noted on the plans. This conductor shall be bonded to box ground terminals, pole ground terminal, ground bus of panel, cabinet, enclosures, and/or ground electrodes shown on the plans.
682.03.2 Secondary Distribution. All trenching shall be performed by mechanical
means and all sides shall be straight and vertical. Width of trenches shall not exceed eight
8.inches on either side of placed branch circuit conduits. All backfill shall be made with a friable material that has been approved by a visual inspection of the Engineer. The Contractor shall seed trenched areas as directed by the Engineer. All conduits shall be sized as shown on th e plans, or where size is not indicated, the Engineer shall be consulted. All conduits shall be run 2’ 0” outside of roadway shoulder lines where practicable. All conduit field be nds shall be made in accordance with the National Electrical Code, Article 344 for metallic conduit, or Article 352 for non-metallic conduit. All upturned conduits shall be plugged or ends taped to prevent entrance of debris or moisture. A dry swab shall be pulled th rough each conduit to remove any debris or moisture before pulling wire. All flexible conduits shall be liquid tight with proper liquid tight fittings. Conduit mounts exposed on poles or other supports shall be supported at 5’ 0” on center by 2-hole straps. Only approved lubricants that will not harm the conductor insulation shall be used while pulling wires. Each branch circuit shall be labeled with a permanent pressure-sensitive label with proper numbers and letters for identification. All connections shall be made in pole bases and controller panels unless otherwise shown on the plans. Splices shall be made using compression type splice connectors. All splices and connections shall be well taped to provide an insulation equal in rating and thickness to the conductor insulation as follows: st layer - flame retardant, cold and weather resistant vinyl plastic tape. 2nd layer - self fusing, rubber-based insulating compound laminated to all weather grade PVC backing, rated up to 600 volts. 3rd layer - same as 1 st layer. No splices shall be allowed in pull boxes. All runs shall be continuous from controller to pole and from pole to pole. The Contractor shall be responsible for purchasing continuous lengths of wire to achieve the above. Approved jacking or boring methods shall be used where a branch circuit must be placed under an existing roadway. Boring operations shall be kept a minimum of two (2) feet from the edge of shoulder, and care shall be taken not to disturb existing pavement or edge drains. The use of water, which could undermine pavements, shall not be permitted. The jacking or boring site must be returned to its undisturbed state upon completion of the operation. Jacking or boring operations and other incidentals necessary to this operation will be cost of Underground Branch Circuit, Jacked or Bored. The Contractor may jack, bore, or trench at paved ditches encountered on branch circuit runs. Where paved ditches are trenched, all concrete must be replaced at no additional cost to the Department.
682.03.3 Pull Boxes and Junction Boxes. Pull boxes and junction boxes shall be
installed in accordance with the plans. The location of the boxes may be adjusted to accommodate field conditions with the approval of the Engineer. When specified, pads around pull and junction boxes may be required.
682.03.4 Secondary Power Controller. The secondary power control unit shall be
installed in accordance with the plans and sh all present a neat and workmanlike finished appearance. The Contractor shall cooperate with utility in completion of unit.
682.04 Method of Measurement.
682.04.1 Secondary Distribution. Branch circuits shall be measured by the linear foot.
The measurement being computed as follows: Jacked or Bored - Horizontally along the length of the jacked section of conduit. Underground - Horizontally along the trench lengths. Structure mounted branch circuit - horizontally or vertically along the length of the sections of conduit installed. No extra length will be allowed for risers to lighting assemblies or secondary power controllers. The terminals for measurement of lengths will be considered specifically as the center of lighting assemblies, power controllers, and junction boxes. Payment for branch circuit connectors, tape, etc. shall be included in payment allowed for the total length of branch circuits. Hardware, fittings, support devices, excavation, sod, backfill, seeding and other incidentals will not be measured for separate payment, but shall be included in the contract unit price per linear foot for branch circuits. Pull boxes and junction boxes will be measured as a unit quantity per each as detailed on the plans.
682.04.2 Secondary Power Controller. Secondary power controllers complete in place
will be measured as unit quantities per each, which shall include all items necessary to complete the installation.
682.05 Basis of Payment.
682.05.1 Secondary Distribution. Branch circuits of the type specified, measured as
prescribed above, will be paid for at contract unit price per linear foot, which price shall be full compensation for furnishing, installing, connecting, excavating, trenching, backfilling
Referenced in this section
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Source: Standard Specifications for Road and Bridge Construction, 2017 Edition. Pages 709–711 of 1,113. View official source ↗