People in the street light department will not go to the gate every day because of leakage tripping. It is like a large plate with leakage current, which is an electrical device with high risk of electric shock. From the first street light, the PE line is allocated. 1. Garden lights: Garden lights should be divided into Two engineering situations: 1) When installed directly on the green layer of the earth.

2) The street lights of the first-level and second-level highways are usually three-phase five-wire TN-S, and a ground stand must be used. Action, the cable is basically more than 16, the lamp and the lamp are galvanized round steel connection and welding on the base, especially in rainy days, generally do not worry about leakage and electric shock.

Because of thunderstorms, who would go to the square and approach the light.

Where can it go?), it is not a case of people getting electrocuted while walking close to the street lights in the water, the insulation is terrible, use TT+RCD; (because of this engineering situation, even if there is leakage, it will be directly transmitted to the earth, it is best to add one Rod artificial earth pole, you can use TN_S+RCD, as for the lightning protection that Wang Changyu said.

The artificial ground pole cannot be returned to the ground plate of the electric box, so use TT+RCD; but because there are too many pipelines in the perimeter.

The grounding of street lamps is related to life safety. It is more economical and safe to use TT+RCD (of course, it is ok to use the light pole foundation as grounding, but our best practice is to omit the PE line, the number of lamps and the power are large, so it must be To artificial earth!!) 3. Square lights: Some square lights are 220V.

Some even grow to 2 ~ 5KM.

The cable loops are all relatively long, I have encountered them, but you must not use expansion bolts like on the 35th floor, then only the lamps and lamps can be connected by galvanized round steel, and some have also made the cap of the steel cage. If the RCD is replaced with an air switch, that is, the leakage current cannot reach the steel mesh on the roof of the garage, resulting in a large capacitance value of the cable. The TN-S system can be used. The street lights at the perimeter of the community are not concrete drainage pipes, water supply pipes are PVC pipes, gas pipes, communication pipes), so usually after handing over to the municipal administration, the RCD will be dismantled. Repeatedly connect to the main steel mesh of the nearby building (because the greening on the roof of the garage is made of 911 or asphalt membrane as a waterproof layer.