Solar panel side grounding

01:Solar panel frame is grounded

Many people think that the solar panel and bracket are metal body, direct contact conduction, only to consider bracket grounding and not consider solar panel grounding. In fact the aluminum frame of solar panel and galvanized bracket or aluminum alloy bracket have done a coating treatment, which can not meet the grounding requirements, only the the grounding hole of solar panel connected to the bracket to be considered effective solar panel grounding

In general, the grounding holes of the solar panel are used for connection between strings, and the solar panel grounding holes at both ends of the string are connected to the metal bracket.

Another point, solar panel has an aging problem, and it may cause large leakage current or low Insulation resistance to ground. If the frame is not grounded, a few years later, the inverter is likely to report corresponding failure, which will cause failure of normal power generation.

02：The solar panel bracket is grounded

For the solar panel grounding, general use 40 * 4mm flat steel or φ10 or φ12 round steel, and finally buried depth of 1.5m underground, the grounding resistance of the PV module is not less than 4Ω, for those who do not meet the grounding resistance requirements, usually use the addition of anti-drag agent or select the soil where the low rate of embedding.

(flat steel)

(Round steel)

The inverter side is grounded

(NS model PE side / DNS model PE side)

(SDT & DT model PE side)

General work ground (PE side) connect to the PE box in the distribution box, and then to do grounding through the distribution box.

02: Protect ground

The right side of the inverter body has a ground hole is to do repeated grounding, to protect the safety of the inverter and the operator.

(Project one)

(Project two)

The enclosure of the inverter can be grounded separately, or you can share a ground (usually) with the distribution box, as shown below:

(Project three)

Inverter, distribution box share a ground pole

Distribution box side grounding

01:Lightning protection grounding

The lightning protection for AC side generally by the fuse or circuit breaker and lightning surge protector. Mainly on the induction of lightning or direct lightning or other transient over-voltage protection of the surge, the lower end of the SPD connected to the distribution box on the ground bar.As shown below.

02:Box ground

According to the "construction electrical engineering construction quality acceptance standard" 6.1.1 cabinet, screen, table, box, disk metal frame and basic steel must be grounded (PE) or zero (PEN) reliable; Installed doors with electrical appliances, the ground terminals of door and frame should be connected by bare braided copper wires and are marked.

There need to do jumper for the door and cabinet of Distribution box to ensure reliable grounding, as shown below:

All grounding lines inside the distribution box shall be connected with PE bars, and then lead to other components

The grounding method of household PV system is described from solar panel ,inverter and distribution box, hope it’s helpful for user.