Provide a design for a complete electrical system with specifications and drawings that show floor plans, riser diagrams, schedules, all power, lighting, and communication plans, including any necessary details to accurately depict the scope of work included in the project. Design must include all conductors, raceways, fittings, circuit protection devices, wiring devices, fixtures, panel boards, boxes, supports, meters, switches, and other electrical equipment necessary to furnish a complete electrical system for the facility. Design must specify the necessary testing of the system prior to being put into service.
Give special attention to the coordination of the installation of electrical equipment that is specified in other divisions (particularly Division 23). These pieces may, in general, include motor starters, controls, relays, etc. that are associated directly with the piece of equipment. Power wiring to all equipment must be specified under this Division 26, regardless of the division under which the equipment is specified.
Consult the Manual for Planning and Execution of the State Permanent Improvements for information concerning requirements, codes, and standards that are applicable to this design. The design shall comply with all local codes having jurisdiction, OSHA regulations, ADA compliance, applicable seismic codes, and any other codes that may apply. The design engineer shall interpret any conflicts or discrepancies, which may arise between applicable codes and shall enforce the more stringent of any requirement.
Clearly specify that the products to be provided for installation under this Division are in strict accordance with the Product and Material listing for this Division.
See document Medium Voltage Cable Specification for product details.
Do not deviate from National Electrical Code (NFPA 70)
Specify that the contractor’s personnel who will be making the splices, terminations, and/or stress cones on medium voltage (primary) cable be required to present evidence of past successful experience in this trade. It is preferable that this task be done by a single individual throughout the project.
Specify color coding for conductors according to the following:
See information in Division 33 for instructions regarding cable installation for delivery of electrical service to the facility service point.
Specify that all ground connections are to be of a type which will ensure against corrosion and electrolysis, and that connections are to be of the brazed, welded, bolted, or pressure connected type except that bolted connections are to be use for connections to removable equipment. Specify that all grounding systems are to be interconnected with the main electrical service grounding conductor.
Specify that all exposed non-current-carrying metallic parts of the electrical equipment, raceway systems, and neutral conductors are to be grounded as permitted by the electric code, but shall not be grounded by connections to the grounded circuit conductors.
Specify that all neutral circuit conductors beyond the service entrance switch shall be insulated in all cases. Service entrance cable without individual insulation on the ground circuit conductor shall not be used beyond the service entrance.
Specify that ground connections for all panelboards, cabinets, wiring gutters, or troughs are to be by means of bonding the enclosure to the separate grounding conductors in accordance with the requirements of Article 250 of the National Electric Code, and that a green colored insulation grounding conductor, sized as indicated or as required by the code, is to be installed in all raceways.
Specify that the transformer’s neutral conductor is to be bonded to the substation housing.
Install a loop of #3/0 AWG stranded, bare copper wire around the unit substation base, at the floor within 2 inches of the side of the 6 inch concrete base. Specify that all connections between wires and ground rods are to be visible. Attach (braze) a ¾” x 8’-0” copper weld ground rod to the loop at each corner of the substation above the floor. Specify that additional rods shall be added to obtain a minimum of 5 ohms of resistance between the neutral and each rod. Specify that one #2/0 AWG bare, stranded copper wire is to be installed at each corner of the loop and run to the substation housing.
Specify that one #2/0 AWG bare, stranded copper wire is to be run from two opposite corners of the grounding loop and exothermically welded to a steel building column if applicable. Specify that one #2/0 AWG bare, stranded copper wore is to be run from one of the remaining corners of the loop and exothermically welded to the largest cold water line available.
Consult with the Project Manager concerning the Owner’s requirements for a “Clean Ground” versus an “Isolated Ground,” if any.
Specify that firm, neat supports are to be provided for all electrical equipment and raceways, using shop coated standard steel shapes, light steel framing members, or prefabricated structural systems, and that all supports exposed to the weather are to be hot-dip galvanized.
Specify that conduit hangers for banked conduit runs are to be made of steel angle, channel iron, or light steel framing, of adequate size and supported by steel all-thread rods from ceiling inserts or building structure. Specify that single conduits are to be supported by means of clamps to the building structure or pipe hangers supported by steel all-thread rods from ceiling inserts or building structure. Do not allow the use of wire supports or perforated steel straps.
Specify that galvanized rigid steel conduit, intermediate metal conduit, and electrical metallic tubing are to be firmly fastened within three (3) feet of each outlet box, junction box, cabinet, or fitting, and that the types used are to be suitable to the particular location and type of construction to which attached.
Specify that electrical hangers shall be mounted to the building structure and should not be attached to other mechanical systems.
Specify that raceways are to be provided for all conductors and cables and that the minimum size of any conduit shall be ¾”, and that a pull wire be installed in all empty conduits. All raceways are to be installed in straight lines, parallel and/or perpendicular to building lines. Conduit shall be installed with no more than 360 degrees of bend and 100’ of length between pull boxes.
The design must provide for two conduits (one used and one spare) for each service entrance to the facility.
Specify that Galvanized Rigid Conduit (GRC) or Intermediate Grade Metallic Conduit (IMC) is to be used as Service Entrance, Feeders, Raceways installed below grade (coated with bitumastic coating), Raceways for grounding conductors, Interior exposed raceways up to 7’-0” above finished floor, Raceways installed outdoors, and Branch circuit raceways exposed to weather
Specify Electrical Metallic Tubing (EMT) may be specified for use as Branch circuits concealed in walls or ceilings and Interior exposed raceways 7’-0” above finished floor
Specify the use of flexible conduit for connections to lighting fixtures and vibrating equipment. The maximum length of flexible conduit shall be 6 feet.
Specify the installation of proper fire-stopping material where conduits pass though rated wall or ceiling assemblies.
Specify the use of suitable extensions or plaster rings as necessary to come flush with he finished surface in which the boxes are mounted.
Specify that all junction boxes shall be installed with a screw attached cover plate.
The installation of cable trays shall follow each hallway according to the building plan.
Specify that each major piece of equipment, electric starter, motor panel, and control device be provided with name plate attached for identification.
Specify that all panels be labeled on outside top of door frame.
Specify that color coding is required for all service, feeder, branch, control, and signaling circuit conductors as follows:
Specify that conductors smaller than #6 AWG or smaller are to be color coded with a solid color insulation, and that colored, permanent, non-aging, insulating tape banding at conductor ends may be used on larger sizes. Green colored grounding conductors are to be installed in all raceways. Require that multi-conductor cables for control, signal, and alarm circuits requiring a ground wire are to be color coded in accordance with IPCEA Standards, except as noted otherwise.
Specify that multi-colored cord is to Type “SO” and is to contain a green colored grounding conductor.
Specify that identifying markers are to name the contents of the conduit in full or abbreviated form with black letters on a background color as follows:
Specify that markers are to be placed at all junctions and terminations of raceways.
Specify that, wherever possible, the position of markers is to be such that the view of them is unobstructed, preferably placed lengthwise along the raceway, or, where not suitable, that the markers be wrapped around the raceway to form a tag.
Provide arc-flash hazard warning labels on equipment. Install labels as required by the NEC. Labels should indicate the available energy, personal protective equipment requirements and approach distances.
University power is transmitted at 4160 or 12,470 volt wye, 3 phase, 4 wire, 60 cycle AC. The existing 4160 volt system is in the process of being phased out and must not be used to power new construction unless written authorization is given be the Clemson University Utilities Director.
Clemson prefers that any unit type substation be located in a separate electrical equipment room. Consult with the Project Manager for possible exceptions to this desire.
The unit substation shall reflect the following components and features:
Secondary voltage within the facility shall be distributed at 12/208 volts, 3 phase, 4 wire wye with grounded neutral, unless 50% of the power consuming equipment in the facility will be capable of utilizing a 480Y/277 volt system. The final selection of voltage must be based upon careful consideration of the type, amount, and location of the various building loads, as well as the physical size and arrangement of the building and the probability and direction of future expansion. Two unit type substations, one providing service at 277/480 volts and the other at 120/208 volts, may be justified for some buildings.
The unit substation shall be furnished with a 2.5 ampere, 120 volt thirty minute interval, class 2 primary reading watt-hour demand meter and the instrument transformers required to meter the secondary load of the transformer. The watt-hour meter shall be semi-flush, draw-out type with built in test facilities.
Specify that the unit substation shall be mounted on a concrete pad with a minimum height above the floor of 6 inches.
Specify that one set of spare fuses for the high voltage section of the substation be furnished and mounted in the high voltage compartment.
Specify that safety switches are to be 240 volt, or 600 volt as indicated, with quick-make, quick-break operating mechanism, and that safety switches are to be heavy duty type with full cover interlock and indicator handle.
Specify that safety switches are to meet applicable requirements of Federal Specification W-W-865C for heavy switches. They are to be UL listed, and are to meet the applicable requirements of NEMA KS1 for Type HD.
Specify that the number of poles, ampere rating, whether fusible or non-fusible type of NEMA enclosure, and other data is to be as noted, and that safety switches are to be securely mounted to the surface on which they are installed.
Cabinets for all panelboards are to be large enough to provide a minimum wiring gutter space 4” wide by 5” deep on all four sides. Specify that front trim is to be single sheet full-finished, code gauge, sheet steel, and that door opening is to expose only the operating handles of the circuit breakers. The inside of the door shall accommodate a typed directory card, protected by a heavy sheet of unbreakable transparent plastic. See attached Labeling Guidelines for Electrical Panels.
Specify that panelboard buswork is to be copper and all branch circuit breakers are to be bolt on type.
Specify that all panelboard front trim and door are to be given a coat of rust-inhibiting primer, followed by paint to match the adjacent wall surface.
The designer shall allow for at least 25% spare breaker space in every lighting and power panelboard.
Specify that all motor controllers are to be equipped with thermal overload protection in each phase, and short circuit protection. Magnetic type motor controllers are to have under voltage protection when used with momentary contact pushbutton stations or switches, and are to have under voltage release when used with maintained contact pushbutton stations or switches.
Specify that when used with a pressure, float, or similar automatic type or maintained contact switch, the controller is to have a “Hand-Off-Automatic” selector switch, and that connections to the selector switch are to be such that only the normal automatic regulatory control devices will be bypassed when the switch is in the “Hand” and “Automatic” positions. Specify that control circuit connections to any “Hand-Off-Automatic” selector switch or to more than one automatic regulatory control device is to be made in accordance wit manufacturer’s approved wiring diagram.
Specify that enclosures for starters and controllers shall be NEMA 1 per NEMA ICS6, unless otherwise indicated.
Specify that manual starters are to be single, double, or three pole, designed for surface mounting as indicated.
Specify that multiple speed motor controllers and reversible motor controllers are to be across the line type, electrically and mechanically interlocked. Multiple speed controllers are to have compelling relays and are to be multiple button station type with pilot lights for each speed. Combination starters are to be provided with integral circuit breakers.
Specify that motors and motor controllers are to be furnished with the driven machine under the respective specification section, unless otherwise noted, sized to assure the specified output and operation of the driven equipment without excessive temperature rise, and suitable for the environment in which they operate. Specify that specific motor characteristics are to be determined to insure provision of correctly sized starters and overload heaters. Motors are to be designed to operate at full capacity with a voltage variation of plus or minus 10% of the motor rating. Motors are to be of sufficient size for the duty to be performed and are not to exceed their full load nameplate current rating when driven equipment is operated at its specified capacity under the most severe conditions likely to be encountered.
Unless otherwise specifically indicated, specify that motors of ½ horsepower or smaller are to be for 120 volt operation, single phase, 60 hertz. Motors of ¾ horsepower and larger are to be for operation on 208 volts, three phase, 60 hertz, or 480 volts, three phase, 60 hertz as required.
Specify that the selector switch is to have a means for locking it in any position, and that for each motor not in sight of the controller, the controller disconnections means is to be capable of being locked in the open position or a manually operated, non-fused switch which will disconnect the motor from the source of supply is to be placed within sight of the motor location.
Specify that overload protective devices are to give adequate protection to the motor windings, be of the thermal inverse-time-limit type, and include a manual reset type push button on the outside of the motor controller case. The cover of a combination motor controller and manual switch or circuit breaker is to be interlocked with the operating handle of the switch or circuit breaker so that the cover cannot be opened unless the handle of the switch or circuit breaker is in the “Off” position.
Specify that all pilot devices, such as thermostats, pressure switches, limit switches, pilot lights, float switches, control switches, control relays, and the like are to be provided under Division 23 – Heating, Ventilating, and Air Conditioning, providing all control supervisory functions indicated and/or specified.
Specify that all pilot devices are to be ruggedly constructed mechanically and properly insulated for the control voltage. Pilot devices are to be conservatively rated with precious metal contacts to handle inrush and continuous currents of the control system and suitably enclosed for the environment and for the type and class of area in which they are installed, with all necessary provisions made for external connections thereto.
Specify that control circuits generally are to be provided with individual control power transformers and adequate over-current and short circuit protection to meet code requirements. Unless otherwise required, control circuit voltage is not to exceed 120 volts, 60 hertz.
Specify that pushbutton stations are to be provided with “start-stop” momentary contacts having one normally open and one normally closed set of contacts and ruby indicating lights to indicate when the motor is running. Specify that stations are to be heavy duty, oil tight, designed for either flush or surface mounting, as required, and that pilot and indicating lights are to be transformer, resistor, or diode type.
Specify that equipment connections are to include the providing of power wiring for the connection of motors and control equipment under this section of the specifications, and that except as otherwise noted or specified, automatic control wiring, control devices, and protective devices within the control circuitry are not included in this section of the specifications but are to be provided under other applicable sections.
Specify that all motors and motor operated equipment are to be checked for proper clearance and alignment and lubricated, if necessary. Specify that motors are to be wired using a short section of liquid tight, flexible metal conduit, unless otherwise indicated, in which shall be provided a grounding jumper, and that the motors are to be checked for proper rotation and left in completely satisfactory operation condition, all under this division.
Specify that motor controllers are to be firmly mounted and wired under this division, unless otherwise pre-mounted and pre-wired integrally with the driven equipment, and that motor controllers are to be accessibly located, equipped with properly selected overload heater elements, and checked for proper contact alignment and proper operation.
Specify that pilot devices, disconnect switches, etc., are to be firmly and accessibly mounted and set or adjusted as required, and that the contractor for this section is to review all parts of the contract documents, particularly work covered under this division, and connect all motors, devices, etc., shown in the contract documents.
Unit substations shall include one switchboard type AC indicating voltmeter and six position transfer switches to provide readings of the one-to-ground and line-to-line secondary bus potentials. It shall also include one switchboard type AC indicating ammeter and a three position switch to provide readings of the secondary bus currents.
New construction and major renovations must include sub-metering of lighting, plug loads, equipment loads, and HVAC by floor, major departments, and/or other functional operational units featuring connectivity to the campus Johnson Control Metasys. Main meter shall provide connectivity through Ethenet to Powerlogics server.
Specify that all devices shall be mounted plumb and at the height indicated.
Do not allow the use of oversized or “jumbo” cover plates except where there is no other reasonable alternative.
Specify the installation of duplex outlets in hallways for use by floor cleaning and other housekeeping equipment. Outlets shall be rated as needed for the equipment to be used.
Specify installation to conform to the requirements of Underwriter’s Laboratories “Standards for Lightning Protection Systems (UL96)”.
The use of incandescent and low voltage lighting is not permitted.
The use of LED lighting fixtures is highly desirable where suitable products are available.
Indoor lighting levels shall be as recommended by the Illuminating Engineering Society of North America, IESNA. Careful consideration of the end user must be used in classrooms and labs with special needs or multipurpose uses.
Lighting voltage shall be 277 volts when available.
For general purpose lighting, specify installation of 24”x 48” fluorescent fixtures with energy efficient T5 or T8 lamps. Specify that the fixtures are to be furnished with rapid start lamps.
Support for all fixtures must be in accordance with all applicable structural and seismic requirements. Fixtures shall be supported independently of ceiling grids.
All exposed fluorescent bulbs shall be protected from breakage with safety tubes and end caps at time of installation. Specify that any plastic used in the fixtures will be fireproof, not subject to disintegration or discoloration with age. All fixtures shall comply with applicable requirements of Underwriter’s Laboratories.
All lighting fixtures must be accessible using standard vertical devices such as A-frame ladders. Inaccessible locations will require automatic winches or if articulated lifts are required, they shall be provided as auxiliary building equipment stored in a logical place within the building.
Specify type and location of emergency lights in accordance with design codes.
The University uses several different exterior lighting fixtures and poles, depending on the application and location. The different applications may include walk lights, street lights, major highway lighting, and parking lot lighting, both within the historic district and within the general campus area. These fixtures are listed in the Products and Materials section of this Division. Consult with the Project Manager for details concerning lighting requirements on your project.
Concrete bases are to be placed against any adjacent concrete walks, curbs, or paved areas, with no grass divider.
Concrete bases must have minimum height of 8” above existing grade.
Concrete bases to have ¾” chamfer on all vertical and horizontal corners.
Concrete bases to have 8’ ground rod.
Concrete bases exceeding 36” in depth shall be designed by professional engineer.
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