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Must be collected! You should know the common sense of street lamp installation plan! ! !

Is the main switch of the street light 3P or 4P?

If it is an outdoor lamp, in order  avoid the danger of leakage, a leakage switch will be installed, and a 4P switch should be used at this time.

If the leakage situation is not considered, the main switch can be a 3P switch.

Advantages and disadvantages of different layouts of street lights

One-sided layout

It is suitable for narrow roads, and the installation height of the lamps is required  be equal  or greater than the effective width of the road.

Advantages: good inducement, low cost;

Disadvantages: The brightness (illuminance) of the road surface on the side without lights is lower than that on the side with lights.

Staggered

The installation height of the lamp is required  be no less than 0.7 times the effective width of the road.

Disadvantages: The longitudinal uniformity of brightness is poor, and the inducibility is not as good as that of unilateral layout.

Symmetrical arrangement

The installation height of the lamp is required  be no less than half of the effective width of the road.

Reasonable choice of street lamp installation height, cantilever length and elevation angle

Installation height

The economical installation height of the gas discharge lamp is 10-15m.

The installation height is o low: the glare of the lamp increases;

o high: The glare is reduced, but the lighting utilization rate is reduced.

Cantilever length

The length of the cantilever should not exceed 1/4 of the installation height.

The effect of o long cantilever:

1. Reduce the brightness (illuminance) of the sidewalk and curbs on the side where the lights are installed;

2. The mechanical strength requirements of the cantilever become higher, which affects the service life;

3. Affect the beauty, resulting in the inconsistent ratio between the cantilever and the light pole;

4. The cost will increase.

Elevation

The elevation angle of the lamp should not exceed 15 degrees.

The installation elevation angle of the luminaire is  increase the horizontal illumination range of the luminaire on the road surface. Excessive size will increase glare and decrease the brightness of slow lanes and sidewalks.

Reasonable power compensation options for street lamps

The single-lamp dispersion compensation method is adopted  increase the power facr of various lamps  above 0.9, which can reduce the capacity of the special transformer for street lamps by more than 51% and the line loss by about 75%, which plays a significant role in energy saving.

Street lamp control method

In line with the principle of practical energy-saving, following the practice of most cities day, according  the different requirements of contrast in different traffic periods, the design adopts a control method combining light control and clock control.

That is  say, when the traffic volume is heavy after dark, all street lights are turned on  ensure the safe passage of pedestrians and vehicles; after midnight, as the traffic volume decreases, all street lights on one side are turned off by clock control  ensure normal traffic Under the premise of achieving the most economical energy-saving effect.

The choice of lighting power distribution method?

Short power supply distance

Single-phase power distribution can be used for landscape lighting and road lighting with small calculation load, and the voltage drop and terminal short-circuit current value should be checked. The power distribution cabinet adopts outdoor type, and the botm side is 0.3 meters above the floor for floor installation.

Long power supply distance

Three-phase power distribution is used for large calculation loads, and the three phases A, B, and C in the low-voltage circuit are connected  each group of street lights in turn  avoid three-phase imbalance. The power distribution cabinet adopts outdoor type, and the botm side is 0.3 meters above the floor for floor installation.

The three-phase five-wire circuit used in the low-voltage lighting circuit can effectively reduce the line voltage loss compared with the traditional single-phase circuit.

The size and laying requirements of street lamp cable protection pipe diameter

The tal cross-sectional area of the conducr in the protective tube should not exceed 40% of the cross-sectional area in the tube. The inner diameter of the pipe should not be less than 1.5 times the outer diameter of the cable.

When the cable piercing pipe is buried in the sidewalk green belt, the depth is 0.5 meters, and the D50 steel pipe is changed  cross the street, and the covering depth is 0.7 meters. If the above requirements cannot be met, a C20 reinforced concrete layer is added on the p of the pipe.

Specific practices of street lamp TT grounding system

The local TT system without PE wire is used, and a 300mA leakage protecr is added  the circuit of the outgoing circuit breaker.

All light poles and lamps must be firmly connected  the base steel bar of the light pole as a grounding device. The ground resistance is less than 30Ω. After the light pole foundation is constructed, it must be tested whether the ground resistance meets the requirements.

If the requirements are not met, the grounding level must be increased. For the specific method, see: ""National Building Design Standard Atlas"" grounding device installation 03D501-4.

How  choose a transformer for street lamp design according  the calculated load

The size of the transformer is not a problem. The key is the power supply radius. In the project, the power supply radius of the street light box is usually about 700 (if you want  accurately calculate the voltage drop), so one transformer is sufficient for 1.5 kilometers, and 4.225 kilometers is recommended. 3 street light boxes change.

The capacity needs  be determined according  the tal power of the circuit lights supplied by the transformer, plus 50% reserved (some main roads need  be advertised or reserved for cross-road street lights).

1) There are missing items in your power calculation. The NG250 of the lamp is the power of the high-pressure sodium light source. Don’t forget the power of the ballast, which is generally 10-20% of the power of the light source. This is an estimated value. There is the power value of the ballast in it, just add it in directly.

2) What you are more worried about is the transformer capacity.

After all the power (in KW, active power) is added up, if it does not exceed 80 KW, you can directly divide this tal by 0.85 (that is the power facr of the street lamp), and the number obtained is assumed  be S1. Let S1 be divided by the transformer Capacity, meet the requirements at 70-85%.

Or divide S1 by 0.8  see the value, and just choose a transformer with a standard capacity.

Of course, street lights must consider the use of electricity for traffic signals, advertisements, and urban landscapes. The capacity of the transformer is usually reserved at 70%, but it must be combined with the owner  reserve this amount of electricity.

If the transformer capacity is greater than 100KVA, low-voltage compensation must be considered. The calculation method is the above method, but the power facr of 0.85 is changed  0.9 or 0.92.

Source: LED Lighting Forum

Shenzhen Shangzheng Lighting is a lamp manufacturer focusing on R&D and production of LED landscape lighting and outdoor lighting. It has 9 years of experience in military industry lighting services. It is located in Shenzhen Baoan. Its products cover: stadium lighting, LED sports lighting, stadium lights, LED stadium lights, High bay lights, high bay lights manufacturers, LED workshop lights, workshop LED lights, tunnel LED lights, LED tunnel lights, LED wer chandeliers, street lights, LED workshop lights, LED squares, lamps, LED lights, high pole lights, wer chandelier, LED Street lights, LED lamps, LED high pole lights, etc. For many years, our company has always put product quality in the first place. At present, the company has passed the ISO9001 international quality certification system, and the products have passed CE, ROHS, 3C and other domestic and international certifications and inspections. We insist on making cusmers feel free  buy and use LED lights. Philosophy and mission, Shangzheng Lighting [Chongde Shangshan is the source of the original] look forward  cooperating with you for a win-win situation!