If a photovoltaic plant is not grounded, the probability of being struck by lightning is very high, and it may also cause a fire, resulting in damage to persons and property. According to IEC 61643-32 "connected to the photovoltaic device surge protection - selection and use of guidelines" in the relevant provisions, whether it is a household or outdoor photovoltaic power plant, need to ensure that the photovoltaic system of lightning protection measures for the implementation of norms.
Therefore, every PV power plant should be well grounded, and the installation must find professional technicians to install! So, a household photovoltaic system grounding including which grounding?
I. Inverter side grounding - work grounding
Photovoltaic power generation system, all non-current-carrying metal parts as well as the shell of the equipment need to be grounded. Work grounding: a single inverter needs to be the inverter PE cable grounding, multiple inverters need to be all the solar inverter PE cable as well as the PV array metal frame connected to the same ground, in order to achieve equipotential connection.
II. Inverter Side Grounding--Protective Grounding
Protective grounding: the left or right side of the inverter body side generally have a grounding hole is to do repeated grounding, to protect the inverter and the operator's safety, inverter chassis protective grounding can be used individually with grounding electrode, but also can be shared with the distribution box with a grounding electrode (usually), as follows: inverter side grounding - protective grounding.
In order to improve the corrosion resistance of the grounding terminal, it is recommended that after the installation of the grounding cable is completed, the outside of the grounding terminal is coated with silicone or painted for protection.
In addition in order to provide the effectiveness of the household PV system lightning protection, for household PV lightning protection also need to pay attention to the following points:
If the system capacity is large or located in a high lightning strike area, additional lightning rods need to be installed next to the square array to improve the lightning protection level of the system;
There are other metal facilities on the roof (e.g. receiving antenna, solar water heater, etc.), the DC circuit should be as far away as possible, and the PV racking must not come into contact with it, and it is recommended that additional lightning rods be installed on the roof;
The area of the series circuit of the system is as small as possible to reduce the intensity of the occurrence of induced lightning;
It is recommended to make a separate lightning protection network for the PV system to avoid lightning intrusion into the PV system through the building lightning protection network;
Summarize
With the fire of the household distributed market, the design and installation of the power station should be standardized simultaneously, lightning protection and grounding can effectively prevent the risk of direct lightning, induced lightning and other lightning strikes, avoiding the PV power station fire caused by lightning strikes and other safety hazards, in short, lightning protection and grounding is no small matter, the preliminary comprehensive and careful design + construction of strict specifications, you can avoid the loss of life and property due to lightning strikes in the later stage!
