SAFETY IN SOLAR PV INSTALLATIONS

Proceedings of the webinar dt Nov 20, 2022 10:30 AM (SUNDAY)

Solar PV is a fast-growing industry in India. India ranks fourth globally in Solar PV generation during 2021. IEC published several standards on safety of SOLAR PV, most of which are adopted as Indian Standards. These standards can be purchased from Bureau of Indian Standards – e-Sale (bsbedge.com)

The general protective measures used in AC system may/will not work in DC. The measure “fault protection by protective equipotential bonding and Automatic disconnection of supply” is impractical in DC side of PV installation. Hence the adopted shock protective measure is Double Insulation or Extra Low Voltage. Practically for DC voltage above 120 V, double insulation is the only recommended safety measure against shock.

Equipment such as PV modules, junction boxes or cabinets, cables used on the DC side (up to the DC terminals of the PV inverter) shall be class II or equivalent insulation as a measure to achieve shock protection.

Protection against fire due to arc require special attention at DC side, not only due to the difficulties in extinguishing the DC arc, but the availability of disconnection devices as well.

Double insulation

Double insulation is recommended against parallel arcs as well. Compromise of this safety measure will be hazardous. For example, majority of fire accidents in SOLAR PV DC side are in combiner box, the main reason being parallel arc due to non-availability of double insulation, added to which the PV panel feeding energy to the DC arc.

It is important to make safe PV installations. This webinar explains about Earthing, Earth Fault protection and Lightning protection in SOLAR PV application. The webinar also explains the recommendations in the latest IEC standards on SOLAR PV installations and is based on.

IEC 62548: Photovoltaic (PV) arrays – Design requirements
IEC 63112: Photovoltaic (PV) arrays – Earth fault protection equipment – Safety and safety related functionality
IEC 60364-7-712: Low voltage electrical installations – Part 7-712: Requirements for special installations or locations – Solar photovoltaic (PV) power supply systems
IEC 62109-1: Safety of power converters for use in photovoltaic power systems
IEC 62446-1: Grid Connected Systems — Documentation, Commissioning Tests and Inspection & Maintenance of PV systems
IEC TR 63227: Lightning and surge voltage protection for photovoltaic (PV) power supply systems