2004 Specifications CSJ 2552-01-033 SPECIAL SPECIFICATION 8676 Solar Panel Power Supply System 1. Description. This work shall consist of furnishing and installing an integrated Solar Panel Power Supply System at the locations indicated in the plans and directions of the Engineer. In this special Specification, a Solar Panel Power supply system is co-located with and supplies operational power for designated ITS field equipment locations as shown in the plans. The Solar Panel Power supply system shall supply power service for the field equipment where the utility power service is not available. The Solar Panel Power Supply System shall contain all of the components described in the material specification and shall be configured as indicated on the plans. 2. Materials. Provide materials that comply with the details shown on the plans, the requirements of this Item, and the pertinent requirements of Item 442, Metal for Structures, Item 445, Galvanizing, and Item 620, Electrical Conductors. The Solar Panel Power Supply System shall employ solar, battery backed power for the assigned field equipment specified in the plans. All equipment, including battery and regulator shall be installed in a suitably sized enclosure. The enclosure shall be sized to house the Solar Power Panel Supply System and all co-located ITS field equipment shown in the plans and as directed by the Engineer. The Solar Panel Power Supply system shall be designed to operate under ambient temperature conditions from -13 F to 140 F for up to 24 hours per day with 5 days of battery backup and shall generally consist of the following: Photovoltaic Module(s) with mounts or racks, and mounting bracket for affixing the Module(s) to a traffic signal pole. Ensure mounting and bracket assembly has all galvanized steel or heavy gauge-mill aluminum construction. Provide adjustable tilt mounts that can be repositioned to an appropriate angle to maximize seasonal solar radiation. 12 VDC sealed, valve-regulated, AGM (Absorbed Glass Mat), maintenance free batteries. Automatic photovoltaic charge controller and monitoring unit. One toggle-type power switch for emergency shutoff. External conduit, wiring cable and conductors (as recommended by the company supplying the system) between the following: Photovoltaic Module to cabinet back panel. Batteries to cabinet back panel Wiring between components in cabinet. 1-5 8676
The equipment installation shall include pre-setting of the equipment, Photovoltaic Module direction optimization, and configuration of hardware components which shall allow automatic operation. The Contractor shall provide a fully operational assembly with all cabling and terminations matched to support the selected components. The Contractor shall furnish, install, and test the Solar Panel Power Supply System, and ensure it meets the following requirements: A. Solar Generator. Ensure the system solar generator provides an array-to-load ratio of 1:1 or greater. Provide a system-average state of charge 90% or greater throughout the entire year. The system-loss-of-load probability must remain 0% throughout the entire year. 1. Photovoltaic Module. The photovoltaic PV module must provide 12 V DC and be capable of recharging the system to full capacity after 6 hr. of continuous operation and in 3 hr. ± 0.5 hr. during optimum sun conditions. Supply industrial grade, polycrystalline type solar modules. Consumer grade modules are not acceptable. Solar modules must have a power output rating of ± 5% or better. Ensure PV modules are available to the Department in a graduated product line from 40 to 120 watts per module. Each solar module, regardless of wattage size, must share common mounting holes for mounting so that a single mounting structure that will accommodate the entire module line. Ensure each solar module incorporates a 6-in. square polycrystalline cells and at least 2 bypass diodes installed at the factory. Construct PV module with a low iron tempered glass surface and an industrial grade anodized aluminum frame that completely surrounds and seals the module laminate. Ensure construction is consistent with the demands of installation near humid salt air environments. Provide an ultraviolet-(uv) resistant, weatherproof junction box providing wire termination for up to No. 6 AWG wiring with the PV module. Design and construct the photovoltaic module mounting assembly of galvanized steel (ASTM A-153 Class A) or aluminum. The mounting assembly must be of adequate design and strength to provide a means of securely attaching the PV module frame to a pole. Provide at least four 3/4 in. stainless steel bolts, lock washers, and hex head nuts with the mounting assembly to secure the PV module to the frame. Provide a mounting assembly capable of 360 horizontal orientation with a means of locking the bracket at an inscribed angular position about the pole. Ensure the mounting assembly is designed and installed to prevent module repositioning during 80 mph wind conditions. The photovoltaic harness must not exceed 2% total voltage drop between the solar module and the charge control circuit. 2. Battery. Provide group-27, 12 VDC batteries. Use valve-regulated, AGMelectrolyte batteries rated for a minimum of 2000 cycles with 10% capacity withdraw. 2-5 8676
Provide a spill proof AGM battery to allow installation in any position. The container/cover shall be polypropylene. The batteries shall be size to allow five days autonomy at 25º F (-4º C). Depth of Discharge (DOD) for the system must not exceed 80%. 3. Panel Controller/Battery Charger. Provide an on-board, solid-state charge control circuit to ensure proper charging on the system battery bank. Incorporate a blocking diode for reverse-current protection of the charging circuit. Incorporate thermal compensation in the charge control circuit to adjust the battery charge rate to variances in temperature with an adjustable voltage swing above and below the ambient set point as defined by the battery manufacturer. The battery float voltage calibration shall be at a voltage defined by the battery manufacturer at 25º C ambient temperatures. Provide LEDs or LCDs to indicate solar panel charging and state of charge. Provide the controller with a low voltage disconnect (LVD) disconnect circuit. This circuit shall disconnect the battery bank when the battery voltage reaches a voltage that is deemed critical by the manufacturer of the battery. Provide an LED to indicate when the LVD circuit is active. B. Control Cabinet. The control cabinet shall be manufactured of unpainted sheet aluminum with a minimum thickness of 0.125 in. The cabinet shall be sized to provide adequate space for the control electronics, desired number of batteries, and all colocated ITS field equipment shown in the plans. Material used in the cabinet shall meet NEMA standards. Provide a completely weatherproofed cabinet to prevent the entry of water. All exterior seams must be continuously welded for the cabinet and door. All exterior welds must be smoothed. Provide the door with a full length stainless steel piano hinge. The hinge must be mounted so that is not possible to remove it from the door or cabinet without first opening the door. The cabinet door opening shall be double flanged. Provide a closed cell neoprene gasket between the door and the cabinet to act as a permanent dust and weather resistant seal. Provide a minimum of 3/8 in. thick gasket. The door shall be tightly secure via a latching device which pulls the door snugly against the neoprene affixed gasket forming a weather tight seal. Provide cabinet with a Corbin style #2 lock with a keyhole cover as an integral part of the door and 2 keys. Provide cabinet with provisions to hold the door open at approximately the 90 degree and 180 degree positions. Provide louvers on each side of the cabinet to allow adequate convection cooling of the electronic components and to prevent the accumulation of gases. Screen vents to prevent entry of insects. Provide an aluminum TX flasher style back panel in the lower compartment with a thickness of 0.125 in. Size back panel to provide adequate space for the control electronics and terminal strip. The electronic components shall be easily installed or removed with simple hand tools. 3-5 8676
Equip the cabinet with two shelves of a minimum thickness of 0.125 in, with a 1 x 3 cutout in the back of the shelves for cable run. Ensure that one of the shelves is capable of supporting a battery weight of about 125 lbs. Provide a rubber mat installed on the shelf that supports the batteries and two 1/8 drain holes located in the bottom of the cabinet at opposite corners. Equip the cabinet with all necessary mounting equipment and hardware. The cabinet shall be configured for pole mounting using two aluminum U channel mounting brackets with stainless steel reinforcing plates on the inside of the cabinet. The cabinet shall also have a 0.25 in. aluminum reinforcing plate mounted in the bottom of the cabinet. C. Wiring. Provide wiring that meets the requirements of the National Electric Code. Provide wires that are cut to proper length before assembly. Provide cable slacks to facilitate removal and replacement of assemblies, panels, and modules. Do not doubleback wire to take up slack. Lace wires neatly into cable with nylon lacing or plastic straps. Secure cables with clamps. Provide service loops at connections. 3. Construction. The Contractor shall submit a system sizing report detailing the photovoltaic array, battery bank, array to load ratio analysis, system availability analysis, battery state of charge report, battery depth of discharge, and shop drawings prior to the installation of the Solar Panel Power Supply system to the Engineer for review and approval. The shop drawing shall include but not be limited to: Details of the complete installation of the system and all components to be supplied Details of all connections between the Solar Panel Power Supply System components Instruction sheets and wiring diagrams for the equipment to be installed The manufacture specifications and catalog cuts and parts lists Particular care shall be given to the interconnection of all of the components and the cabling. The Engineer reserves the right to inspect and/or factory test any completed assemblies prior to delivery of the material to the project site. Any deviances from these specifications that are identified during such testing shall be corrected prior to shipment of the assembly to the project site. The Solar Panel Power Supply System configuration and setup shall be set to assure connection and electric power delivery to the field equipment as indicated in the plans. All equipment shall be located and mounted as detailed in the plans and as directed by the Engineer. 4. Documentation Requirements. Provide documentation in accordance with Article 4, Special Specification, Testing, Training, Documentation, Final Acceptance, and Warranty. 5. Testing. Perform testing in accordance to Article 2, Special Specification, Testing, Training, Documentation, Final Acceptance, and Warranty. Additional testing requirement is as follows: Perform an Operational Test on each Solar Panel Power Supply System installed. This test shall be performed during a minimum of 14 days. The testing period shall include five days solar panel disconnected from the panel controller. The Operational Test shall verify that the 4-5 8676
Solar Panel Power Supply System is fully operative and can supply specified power without misrepresentation. The Contractor shall provide an Operational Test schedule and checklist to the Engineer for review and approval prior to the test. Ensure that a manufacturer s technical representative is available on site to assist the Contractor s technical personnel with the installation and testing of the Solar Panel Power Supply System. 6. Warranty. All components to be supplied under this specification shall be warranted for a minimum of two years. This warranty shall include repair and/or replacement of all failed components via a factory authorized depot repair service. All items sent to the depot for repair shall be returned within two weeks of the date of receipt at the facility. The depot location shall be in the United States. Repairs shall not require more than two weeks from date of receipt and the provider of the warranty shall be responsible for all return shipping costs. The depot maintainer designated for each component shall be authorized by the original manufacturer to supply this service. A warranty certificate shall be supplied for each component from the designated depot repair site indicating the start and end dates of the warranty. The certificate shall be supplied at the conclusion of the Solar Panel Power Supply System Acceptance Test or end of the construction of the project which ever comes last and shall be for a minimum of two years after that point. The certificate shall name TxDOT as the recipient of the service. TxDOT shall have the right to transfer this service to other private parties who may be contracted to perform overall maintenance of the facility. 7. Measurement. This Item will be measured as each completed unit furnished, along with associated materials, installed, made fully operational, tested and accepted in accordance with the Contract Documents. 8. Payment. The work performed and materials furnished in accordance with this Item and measured as provided under Measurement will be paid for at the unit price bid for Solar Panel Assembly. This price is full compensation for furnishing and installing all equipment described under this Item with all cables, connectors and mounting assemblies; control cabinet, mounting and hardware; all documentation and testing; all labor, materials, tools, training, warranty, equipment, and incidentals. 5-5 8676