EnergySafe Magazine May 2014, issue 35 | Page 14

14 Electrical news Solar alteration requirements By John Stolk, ESV Compliance Officer In Victoria an alteration to a solar installation is classed as prescribed electrical installation work, which requires the work to be inspected by a Licensed Electrical Inspector (LEI) and a Prescribed Certificate of Electrical Safety to be issued before the solar installation can be used. Listed are common requirements that apply to existing solar installations when altered, added to or re-configured. These requirements address typical alterations to solar installations; they cannot address every scenario. a. If the inverter’s capacity can accommodate additional panels or altered configuration, the inverter can remain, otherwise an upgrade is required. b. All existing and new panels shall be connected to the installation’s earthing system. This requirement is to prevent the possibility of voltage gradients and creates a safer installation. Reference Equipotential Bonding— Clause 5.6 of AS/NZS 3000:2007—Wiring Rules. c. String wiring must be installed as per AS/NZS 5033:2012—Installation and safety requirements for photovoltaic (PV) arrays. d. The restricted use of cable ties apply to new and existing work as per AS/ NZS 5033:2012—Installation and safety requirements for photovoltaic (PV) arrays. e. Existing isolating devices must to be replaced when identified as: i. not having the correct voltage rating for an earthed array system (1.2 X Voc); ii. polarised circuit breakers iii. rated for AC voltage only iv. f the enclosure is not protected against UV i v. if the enclosure is not mounted as required by the manufacture and diminishes the IP rating f. Existing cables that are suitably rated for purpose (DC rated cable), and cables that complied with the minimum requirements of the Standard at the time of installation, would not be required to be reinstalled in heavy duty (HD) conduit. g. When wiring is relocated or upgraded, the requirements of AS/NZS 5033:2012— Installation and safety requirements for photovoltaic (PV) arrays and AS/NZS 3000:2007—Wiring Rules apply. h. Where TPS cables (suitable for AC) are installed between the solar array and the inverter, and solar array is reconfigured or added to, the TPS cable shall be replaced with suitably rated DC cable. See pg 16 and 17 for further information on solar alterations or go to www.esv.vic.gov.au Additional 2 Panels with Bonding and upgraded isolating device Existing Solar Panel Array Isolating device - Roof Configuration Inverter A.C Switchboard - + + Isolating device + A N E - Scenario one (above)—Adding new panels to an existing array: Original array configured with six panels in series, the alteration consists of installing an additional two new panels in series. If the existing cables or isolating devices do not have the current carrying capacity or voltage rating they must be upgraded to comply with current standards and requirements. Existing Solar Panel Array Additional 2 Panels with Bonding and upgraded isolating device Isolating device - Roof configuration Inverter A.C Switchboard - + + Isolating device A N E Scenario two (as shown above)—Adding new panels to an existing string but changing the configuration of the existing string: The original array configured with 10 panels in series, the alteration consists of installing an additional two new panels in the series but the configuration of the array is to be in two strings of six. If the isolating devices do not have the current carrying capacity, they must be upgraded to comply with current standards and requirements. + -