For non domestic installations at the PCE where the dc array voltage exceeds

For non domestic installations at the pce where the

This preview shows page 29 - 31 out of 101 pages.

For non-domestic installations, at the PCE where the d.c. array voltage exceeds 600 V d.c., restricted access of the array cabling is satisfied where the cabling is in heavy duty conduit or is fully enclosed in an equivalent electrical enclosure which is not accessible without the use of a tool up to and including the PCE input. If in accessible areas, the associated protection and isolation devices shall also be fully enclosed and not accessible without the use of a tool. 3.2 PROTECTION AGAINST ELECTRIC SHOCK All wiring shall be installed in accordance with AS/NZS 3000. Refer to Clause 4.3.6.3 for additional installation requirements. NOTE: Refer to Clause 4.3.2 for PV module requirements. For all LV systems, components and cable in PV arrays shall be protected by double or reinforced insulation between any live conductor and any earthed or exposed conductive part. Because of the risk of d.c. arcs, double insulation is recommended where possible to make NOTE: the installation as ‘inherently safe’ as possible. PV module exposed metal earthing and bonding shall be according to Clause 4.4.2. In systems where the output of the PCE is earth referenced (e.g. in grid connected applications), if a non-separated PCE is used, functional earthing of one of the conductors of the d.c. side is not permitted. 3.3 PROTECTION AGAINST OVERCURRENT 3.3.1 General Faults due to short circuits in PV modules, junction boxes, combiner boxes, PV module wiring or earth faults in array wiring can result in overcurrent within a PV array. PV modules are current limited sources, but because they can be connected in parallel and also connected to external sources (e.g. batteries), they can be subjected to overcurrents caused by either— multiple parallel adjacent strings; or (a) from some types of PCEs to which they are connected or from external sources, or (b) both. 3.3.2 Requirement for overcurrent protection Overcurrent protection shall be provided where it is required by manufacturers of PV modules and associated equipment. If manufacturers do not specify the use of overcurrent protection the need for protection shall be determined according to Clauses 3.3.3 to 3.3.6. Where overcurrent protection is required, devices used shall comply with either— circuit breakers in accordance with Clause 4.3.4; or (a) fuses in accordance with Clause 4.3.8. (b) Semiconductor (solid-state) devices shall not be used for overcurrent protection purposes. Accessed by UNSW - LIBRARY on 06 Apr 2017 (Document currency not guaranteed when printed)
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AS/NZS 5033:2014 28 COPYRIGHT 3.3.3 Overcurrent protection in PV systems connected to batteries Overcurrent protection shall be provided in all PV systems connected to batteries. This protection may be built into the system immediately adjacent to the battery. If this is not the case overcurrent protection shall be provided on the main array cable to protect this cable from fault currents originating from the battery system (see Clause 3.3.5 for overcurrent protection sizing). All overcurrent protection used shall be capable of interrupting the maximum prospective fault current from the battery. If circuit breakers are used, they shall
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