Sensitive elements of sensors and detectors actively enter the everyday life of ordinary citizens, increasing their comfort and safety. Using sensors, you can automate electrical systems and equipment, which also extends the functionality of devices. One of the most popular devices of this type is the built-in motion sensor, which is used to control the lighting system.
Instrument design
Externally, the device is a small plastic box in which sensors of one type or another are placed. Due to the electrical filling and connection to the control panel, the sensor transmits a signal, after which the lighting device is triggered. In this case, the most common design of a built-in hidden motion sensor is considered. Its features include the ability to integrate into a ceiling niche, wall, or prepared connector. The main thing is to leave free access to the sensitive element. Permanent maintenance does not require only wired models, for which only a connection cable is left, but battery-powered devices will periodically have to be removed to update the batteries.
The principle of operation of the motion sensor
All devices of this kind work according to the general scheme - fixing a certain feature in the coverage area, analyzing the signal and transmitting it to the target equipment (control panel or directly to the lighting device). Another thing is that the same annoying sign can be different. For example, luminaires with an integrated motion sensor with infrared sensors are widely used today. They focus on fixing infrared radiation from surrounding objects. In their own way, ultrasonic models are also attractive, which pick up noise reflection at frequencies from 20 to 60 kHz. This principle of operation is characterized by accuracy of signal fixation and independence from surrounding negative factors, but if there are animals in the house, then ultrasound should be abandoned right away.
Not so popular in domestic use, but still retain a certain demand microwave built-in motion sensors, the device of which can be compared with ultra-frequency locators. Models of this type generate microwave radiation, taking environmental reactions to it. A big plus of such sensors is the possibility of detecting a person even on the way to the door, which activates the lighting in advance before entering. But this is also the disadvantage of microwave sensitive sensors, since the false response rate is one of the highest.
Instrument placement requirements
The performance, accuracy of user detection and the same false signal rate are directly affected by the location of the sensor. When choosing an installation point, the following parameters are taken into account:
- Installation height. It is important to focus on the growth of people who will use the lamp. If there are children in the house, then their height determines the minimum altitude level of the device. This does not mean at all that the device itself should be at a height of the order of 1-1.5 m. The zone of functioning of the sensitive element should extend to the approach of children. But, for example, cats and dogs should not fall into it.
- Range of propagation of radiation. The average coverage distance of LED luminaires with a built-in motion sensor is 5-6 m. This value usually determines the installation location of the detector relative to the entrance or area where the user approach should be recorded.
- Angle of coverage. This is the horizontal sector that defines the width of the workspace where the target passes. So, if the room has two entrance doors, then the sensor is located between them so that both sections are simultaneously covered.
What else to consider when choosing an installation location?
It would be useful to foresee possible environmental interference. The slightest obstacle, for example, can reduce the range of the sensor. Most sensors also respond to temperature and light changes. If the climate equipment is located in the room, it is better to mount the sensor in a protected case. For example, in this case, it is advisable to use the installation of a motion sensor that is built into a socket box or other insulated housing. If there is electromagnetic radiation, this will increase the risk of false positives. But even if it was possible to eliminate all the interference in the room, it is necessary to correctly orient the sensors directly to the working area. For example, infrared optics should be positioned so that the lenses are oriented perpendicular to the user's line of motion. These and other nuances are taken into account even at the stage of designing a lighting system.
Typical device connection
First you need to disassemble the design of the device. This operation is easily performed with a screwdriver by unscrewing the rear panel. Inside should be a block for connecting wires. An electric circuit is organized through it with the lighting device included in it. In turn, the detector must open or short circuit, depending on the current status. In the standard circuit, the block has the following notation: L (phase), N (zero), A - usually a wire with an arrow, which should connect the circuit to the target control device. The connection of today's popular LED recessed luminaires with a motion sensor is carried out with the expectation of full control from the side of the sensing element, that is, without a switch. The main advantage of this method is the elimination of the need for access to the distribution box. A wire is sent from terminal L on the block directly to the phase. From the native terminal N, the line goes along the circuit of the neutral wire to the lamp. From terminal A, the wire also leads to the light fixture.
Connection using a switch
From the N-terminal, the wire will be routed to the junction box to the zero circuit. In the same zone, wiring to the lamp is organized. From line L, the phase is led to the switch and connected to the middle (neutral) terminal. In this position, the lighting is controlled via a sensor. But the task of the switch for the built-in motion sensor is precisely to provide the possibility of duplicate manual control. Therefore, another wire connecting the sensor and the lighting device departs from the A-terminal. From the lamp, a wire will be directed to the switch to the terminal associated with the activation of the top position of the key. This part of the circuit is responsible for controlling the lighting with the switch. The lower position of the key is to turn off the light.
Sensor mount
After performing electrical activities, you can install the device in a prepared niche, housing or connector. In the case of integrated sensors, mounting kits often contain special boxes for attaching the device to the same socket boxes. From the master, it is only necessary to make mounting holes for complete self-tapping screws or dowels, and then introduce the housing into the previously created niche of the appropriate size. The motion sensor already integrated in the socket box is additionally masked by a cover or mounting plate. It is desirable that a simple mechanism for dismantling the device is provided, which will facilitate the process of its operation.
Device testing
When the connection and installation activities are completed, you can begin to test the device. But before that, you need to make basic settings in terms of sensitivity. Testing is performed according to several parameters. Firstly, the response quality is evaluated in terms of the sharpness of movement. It is necessary to go through the coverage area several times at a different pace and determine the optimal response sensitivity of the device - if the nature of the detection does not match the settings, it is corrected. Secondly, after switching on, a lamp with a built-in motion sensor must for a certain time (fixed in the settings) maintain an active state. You should detect both the delay time and the duration of the active operating state. The main task of the test is to test the device for compliance with the settings made.
Conclusion
Using a motion sensor is not just a means of improving the ergonomics of the lighting system, but also a sure way to save energy. Correctly completed installation of the device with a suitable connection diagram will certainly save you from operational hassles associated with the constant switching of lights and lamps. For this reason, recessed luminaires with motion sensors are often used by owners of private houses when organizing outdoor lighting. But for urban residents, automation of lighting systems is no less relevant for the same reasons for energy conservation. Thus, according to experts, the inclusion of motion sensors in the network due to rational management allows us to reduce energy consumption by 30-50%.