Ways to connect motion sensors to LED floodlights

Street floodlights are used to illuminate streets and roads, sports and playgrounds, as well as facades of buildings, construction sites, storage areas, etc. They are also installed in places where constant lighting is not necessary at night and it is inconvenient to use the switch (parking lots , adjoining territories, farmsteads, cottages). In order for the spotlights to turn on and off automatically and only if necessary, they are equipped with motion sensors (DD). At the same time, a properly assembled kit is a complete automated lighting system that provides significant energy savings.

Types of motion sensors

The effectiveness of the pair "spotlight + motion sensor" largely depends on the correctly selected DD. In practice, the following are most often used:

• infrared;
• ultrasonic;
• microwave;
• combined.

All of these sensors have both advantages and disadvantages.

Infrared

The principle of operation of infrared DD (IRDD) is based on the detection of changes in the thermal radiation of objects in the observation area. When the object moves, its thermal radiation is alternately transmitted by special lenses to the control sensor, which generates a signal to turn on the searchlight. In this case, the sensitivity and size of the controlled area depend on the number and surface area of ​​the lenses.

The disadvantages of ICDD include:

• the possibility of false alarms (reaction to any heat radiation);
• low accuracy of work on the street due to exposure to direct sunlight and precipitation;
• does not react to shielded objects that do not transmit infrared radiation;
• insufficient operating temperature range.

The main advantage of the ICDD is its high accuracy in adjusting the angle and detection range of moving objects.

Ultrasonic

An ultrasonic wave generator is installed in the ultrasonic DD (UZDD) housing, operating at a frequency of 20 to 60 kHz. The principle of operation consists in the registration of frequency changes by the ultrasonic receiver when the ultrasonic wave is reflected from the moving object. The receiver sends a signal to turn on the lighting.

The main advantages of UZDD:

• low cost;
• high performance in conditions of high dust and humidity;
• the operation of the sensors is not affected by changes in the temperature of the environment and / or moving objects;
• the material of moving objects does not have any effect on the operation of the SPL.

Among the disadvantages of UZDD, one can single out a small range and actuation only on sudden movements of an object in the observation area.

Microwave

The principle of operation of the microwave DD is similar to that of the UZDD. However, unlike the latter, the built-in receiver emits waves with a frequency of about 5.8 GHz of low power (no more than 1 mW / sq. Cm). When the slightest change in the frequency of the reflected signal is detected, the microprocessor generates a command to turn on the lighting.

Advantages of the microwave sensor:

• the ability to detect moving objects behind dielectric or weakly conducting obstacles;
• catches minor movements of the object;
• the ability to work at any temperature of air and objects;
• the presence (if necessary) of several observation zones.

When microwave sensors operate, their response to the movement of objects outside the observation area is possible. They also differ in higher cost. In addition, the constantly emitted microwave waves are unsafe for humans.

Combined

Combination sensors combine several methods of motion detection. In this case, the most successful is the joint operation of IR and microwave sensors. Parallel working motion detection channels make the combined sensor the most efficient and accurate.

How to connect motion sensors to a spotlight

The connection diagram of the motion sensor to the floodlight is so simple that everyone who is familiar with the basics of electrical engineering and the rules for conducting electrical work can assemble it. The DD works like a circuit breaker and must be connected between the floodlight and the mains socket. To connect the DD to the spotlight, you will need a screwdriver, electrical tape, pliers, a mounting knife, a soldering iron, a multimeter, and electrical wires of the required length (for stand-alone DD installation). The presence of a screwdriver will not hurt either.

If the DD is built into the body of the floodlight, no electrical work is required. They are needed in cases where the DD is installed autonomously directly near the searchlight or at a distance from it.

Connection procedure

Connect the DD to the spotlight as follows:

1. They disassemble the DD - inside there is a terminal block with three conductors connected to it blue (zero), brown (power supply phase)), red (load). CThe vents of the conductors may differ from those indicated, therefore, for the reliability of the wire, it is recommended to ring with a multimeter.
2. The searchlight is disassembled - there are two wires inside: zero (blue) and phase (red).
3. Connect the searchlight to the DD, for which they connect (through the terminal block) red and blue wires (zero).The terminal block contact "zero" must connect all three components to each other - the power grid, the spotlight and the DD. To do this, twist the stripped end of one wire from the power cable with a blue conductor from the spotlight and then connect it to the blue DD wire through the terminal block.
4. Insert the stripped end of the phase wire of the power cable into the remaining socket of the terminal block.
5. After checking the correspondence of the wires connected to each other and finally tightening the screws in the sockets of the terminal block, collect the DD and the searchlight.

Then you can connect the system to the power supply and start testing and configuring it.

DD can work with spotlights, in which incandescent, halogen, LED, fluorescent lamps can act as a light source. In this case, the connection diagram remains unchanged.

The use of powerful searchlights will require the inclusion of special contactors (magnetic starter) in the connection diagram, which remove part of the load from the DD contacts.

DD adjustment

When installing a floodlight with DD, first of all, set the device so that the observation area is the largest. In this case, the height of the placement and the angle of its installation are important. The angle of installation is adjustable by means of a hinged mount, and the parameters of the vertical view are indicated in the instructions for use.

The operating parameters of the floodlight with DD are adjusted using the controls, the knobs of which, for convenience, are brought out to the sensor body. They are located at the bottom of the DD and are marked accordingly.

SENS (sensitivity) - adjusts the intensity of movement to which the DD should react. First, it is recommended to set the regulator to maximum and check how the sensor reacts to the appearance of a moving object (person, car, etc.) in the observation area. Typically, the detection distance is 2-8m.DD should not react to flying birds and swaying tree branches.

LUX (illumination) - adjusting the illumination level, set the regulator to the MIN position. In this case, DD will only work in complete darkness. If necessary, the illumination level is changed.

TIME (delay time) - sets the operating time of the spotlight after the moving object leaves the observation area. As a rule, the time delay is set in the range of 5 sec. up to 8 min.