Installation of 520W Ground Mount PV System
System consists of: 4 x 130W Kyocera modules in a single string (80V), OutBack MX60 maximum power point tracker regulator, Exide 1080Ah @ 12V battery bank and Selectronic SA21 inverter.
14 November 2007
Dave, Ralph and Warren wire up module interconnect cables and string protection/array isolator.
Due to high risk of lightning, PV array earthing of exposed conductive parts for lightning protection and equipotential
bonding (system bonding) is used. Warren is sealing the end of the protective conduit to prevent the ingress of water and insects to the array marshalling box.
Earth stake for array system bonding (above) and earthing of MOVs (metal oxide varistors - below). Earth stake is driven 1.2m into ground, connecting clip is painted with zinc paint to prevent corrosion, earth cables are mechanically protected with conduit and secured with cable ties and half saddles.
Array marshalling box has extra fuse holders for later expansion. HRC fuse switches are used for string protection and as a "no load" array isolator. MOVs are installed above on array side of fuses using heat shrink and wire ends (boot lace end style wire terminators). MOVs are earthed in the middle (green heat shrink). NB. string over-current protection isn't required in this installation (one string only) but due to the possibility of later expansion, has been provided. Also, as the modules are double insulated (Class II) and have no system earthing, string protection is only required on one pole, however, due to the potential of a different configuration being utilised when the system is expanded, double pole fusing is used.
Dave, Warren, Ralph, Don and Rezza working on the battery enclosure and DC distribution box. All exposed wiring is installed in conduit and secured with half saddles to the exterior wall.
AS4086 compliant battery enclosure: vermin proof, passive cross ventilation, protection from weather, no spark hazards above vents, battery cables penetrate enclosure below top of battery.
DC distribution box. All cables protected and secured. Box has IP65 weather proof rating.
Dave checks his work. DC distribution box provides circuit breakers for for battery charger, PV array and loads.
OutBack MX60 maximum power point tracker in weather proof housing (meter box).
Solar DC isolator (double pole, load breaking, and lockable in off position)