Owners of country houses often want to organize autonomous lighting on their personal plot. There are two options for arrangement - installation of a light sensor or an astrotimer. The first device is considered more preferable because of its reasonable cost and simple design with interchangeable parts.
The principle of operation and the device of the day-night sensor to turn on the light
The day-night sensor has many names, the most common among them is the photo relay. Despite the large number of names, the task remains one - to turn on and off street lighting automatically.
The principle of operation of the light sensor is based on the ability of some structural elements to respond to the intensity of ambient light. For this purpose, photoresistors, phototransistors and photodiodes are most often used. With a decrease in illumination with the arrival of evening, the light sensitivity of one of these parts begins to change. As soon as the changes reach the set parameters, the closing relay is triggered, which ensures uninterrupted power supply. With the arrival of the morning, the reverse processes take place, the contacts in the relay open and the lighting is turned off.
Characteristics and selection criteria
First of all, you need to decide on the type of relay used. It must be equipped with a built-in light sensor or an external one. The remote is small in size, it is easier to protect it from backlighting, the device itself is installed at home, for example, in a switchboard. There are even modifications for din-rail.
A photo relay equipped with a built-in light sensor should be located near the lighting device. Also during installation it is important to take into account that the light of the lamp can affect the photosensor, this must be avoided. A day / night sensor with a built-in element is preferable to use, for example, for solar-powered luminaires.
Performance characteristics
Technical parameters of possible modifications:
- Load power. Each sensor is designed to operate at a specific load power. It is recommended that the wattage of all lighting fixtures is approximately 20% less than the rated power. In this case, the equipment will not always be overloaded, which will have a favorable effect on the operational life.
- Enclosure protection class. Devices intended for outdoor use must have a protection class of at least IP44. This indicates that dust and water particles larger than 1 mm cannot penetrate into the case. On the street, you can install devices with an even higher class of protection, less is impossible. For home use, you can purchase designs with IP23 protection.
- Use mode. If the timer for the lighting lamp is to be operated year-round, it must be designed to operate at low and high temperatures. It is recommended to take indicators with a margin in case of abnormal heat or cold.
- Supply voltage. It can be either 220V or 12V. Basically, the choice depends on the type of voltage that powers the street lighting.12V lighting fixtures can also be used with rechargeable batteries.
The right choice will ensure that your light timer runs smoothly and efficiently.
Customization options
There are several adjustments that will allow you to customize the operation of the sensor for a specific situation. The equipment settings at the initial stage of use are carried out manually by turning the required regulator. It is almost impossible to achieve the same parameters.
- Adjustable illumination range. This parameter sets the lighting at which the relay closes and opens the contacts. The range can vary from 2 to 100 Lx in complete darkness, and from 20 to 80 Lx at dusk.
- The triggering threshold allows you to decrease or increase the photosensitivity. It is recommended to reduce this parameter in winter, when there is snow on the ground and the sensors react to it. It is also reduced if brightly lit objects are located in the immediate vicinity.
- Delay, measured in seconds, to turn off and on. Increasing the switch-off delay reduces the number of false alarms, for example, when the light from the headlights of a car hits the sensor. The turn-on delay, in turn, will prevent the lighting device from turning on when it is darkened from the shadow of a bird or from a cloud.
Thanks to these settings, you can ensure the correct operating mode of the equipment, extend its life and save energy.
Choosing a suitable place to set the off timer
For uninterrupted and correct operation of the photosensor, it is necessary to choose the right place for its installation. The following factors are taken into account:
- The device must be exposed to sunlight. The structure should be in the open air or canopy, but not at the very top.
- Lamps, lights and windows should be located as far away as possible as they can cause frequent false alarms.
- It is not recommended that the day / night sensor is regularly exposed to light from the headlights of a car.
- Do not mount the sensors too high. This will cause difficulties in maintenance and preventive measures.
Cases are common when sensors are installed directly on poles, but this is not always practical and convenient. It is preferable to fix it to the wall of the house and run the power cable.
Connection diagrams
Connecting a time switch for street lighting should be straightforward. The phase and zero are entered at the input of the device, from the output the phase is applied to the load - lighting devices, zero comes from the machine or the bus.
If the installation is carried out in accordance with all the rules and regulations, the wiring will be made in the junction box. If you have to turn on a powerful lighting device, it is recommended to supplement the circuit with a starter (contactor). If the lamps should light up only with the arrival of a person, the automatic lighting system is additionally equipped with a sensitive motion sensor.
Most models include three wires: black or brown, red and green. It is important to consider the following when drawing up a diagram:
- A phase must be supplied to the black or brown wire.
- The red wire is required to connect the device to the lighting fixtures.
- The green wire is connected to the neutral from the power cable.
With the correct connection of all wires, a completely working diagram will be obtained.
How to set up a time relay for outdoor lighting
Light control equipment is most often installed in close proximity to the lighting devices connected to it.The connection diagram in each case is different; it is required to choose in accordance with the instructions in the accompanying documentation. It is required to read it before performing work.
It is not at all necessary to have special skills to carry out installation work. It is only important to calculate the distributed load in such a way that the lighting fixtures do not cause overvoltage in the network. The day-night sensor practically does not load the electrical network. However, in the switchboard, the RCD and the sensor itself must be selected based on the total power of the connected bulbs.
Experts have highlighted a few simple recommendations for installing light sensors:
- If a large number of light bulbs are connected, the circuit must additionally be equipped with a magnetic starter.
- Do not place an electrical device near flammable materials, chemicals and heating elements.
- Often inexperienced people make a mistake - they install the sensor upside down, which is absolutely impossible to do. Rays of sunlight can fall on it, but with the arrival of darkness, artificial lighting from the rooms will affect.
- It is recommended to connect the twilight switch and the entire system of lighting equipment on a separate line from the electrical switchboard with a circuit breaker.
The main condition for correct operation is that the light from any lighting fixtures should not hit the sensor. Otherwise, the work will be incorrect, the number of false positives will go off scale.
