B08 AMD_Tooele 2MW PV_01 10 10_page 26.pdf

ERCIP 1.5MW Solar Photovoltaic Array Tooele Army Depot, UTAH

01 10 10-17

4.8 ARRAY MOUNTING AND ORIENTATION

Each framed photovoltaic module shall be mounted on an integrated system of support racks. The orientation of the modules shall be due south with a 36 degree upward tilt. The mounting system may utilize integrated wind deflectors to lessen wind loading upon the rack structures, provided deflectors do not shade array. Fixed modules shall be used. Provide a 3:1 spacing to height ratio between adjacent racks, height measurement relative to lowest edge of PV modules on each. Bottom of racks shall be 24” off the ground minimum to clear snow build-up and weed growth. Rack structure and earth anchors shall be designed and treated to be corrosion resistant where in contact with the ground.

4.9 WIND LOADING

A. At the Design/Build Contractor’s option, integrated wind deflectors may be provided to minimize wind loading.

B. The system design shall meet requirements of the system manufacturer for ability to meet the specified local standards for wind design speeds for the particular application.

4.10 SYSTEM ELECTRICAL

A. The modules shall be electrically connected by “quick connect” electrical connectors, which shall be UL listed for service in high-voltage photovoltaic systems to create electrical series-circuits (strings) according to the system specifications. The system shall have terminal boxes to provide the electrical circuit strings a secure entry to the conduit leading to the combiner boxes. DC cables may be routed on the back side of the modules near rack centerline as indicated, and shall be UV, sunlight resistant and wet location rated “PV-wire”. Exposed cables are to be routed near the rack centerline to keep them off the ground yet well under the racks, and shall be protected from physical damage, particularly during grounds maintenance such as clearing weeds and brush. No exposed cables should be within 3’ of finished grade for this reason. Size DC conductors for voltage drop, with current-carrying DC conductors sized not smaller than #10. DC conductors shall use 90 degrees C insulation.

B. The system shall have switched combiner boxes, containing fuses and a bus to combine the outputs of the strings. Re-combiner boxes shall be provided to reduce the number of inputs to the inverters to a manageable quantity. Re-combiner boxes may use fuses or circuit breaker (either way sized per the NEC). Multiple circuits shall run from the combiner and re-combiner boxes via underground conduits and pullboxes to the inverters, sized for voltage drop. Combiner boxes and pull boxes shall be installed at the end of each rack of PV modules, for effective management of the DC cable system. All combiner and re-combiner box terminations shall be checked to verify there is no “reverse polarizing”.

C. The system shall have 1.5MW utility interactive inverter/s capacity for base bid 1.5MW PV system (inverter count/capacity would increase if options of 0.25MW increase up to 2MW PV are exercised), unless approved otherwise by the government.

D. The DC system voltage shall be 1000 VDC. This will allow for fewer system losses and thus a more efficient system, yielding maximized power production. If a lower VDC system is proposed, the l2eddmn9 Highlight