Presence sensors are used constantly in residential and building installations, although the installation of the presence sensor is relatively simple to install, it is still common to raise doubts on this subject. We will explain what a presence sensor is, how a presence sensor works, in addition to teaching through the connection diagrams three ways of installing the presence sensor, making a simple connection, only of the presence sensor, another connection using the sensor presence with a simple switch and the last connection of the presence sensor using a parallel switch, come on guys!
What are the sensors?
Sensors are devices that basically have the function of detecting, signaling and responding quickly and efficiently to any stimulus. There are several types of sensors that respond to several different stimuli, such as a simple movement or absence of material or object for example. There are also sensors that are capable of detecting changes in temperature, pressure, brightness, distance, and others.
As soon as the sensor receives a certain stimulus, its function is to emit a signal that is capable of being converted and interpreted by other devices, thus being the basis for monitoring and controlling a production process or even the activation of other devices, machines, equipment or devices, such as the activation of lamps, electronic gates and alarms for example.
The choice of the sensor depends exclusively on the purpose of your installation. Therefore, it is necessary to evaluate the conditions of the environment and choose the most appropriate sensor for that activity. We will teach you how to install a presence sensor to activate a lamp, showing three ways of installing the presence sensor.
Presence sensors: what is how it works.
Presence sensors are commonly used in residential, commercial and building electrical installations, mainly for driving lamps or doors for example. Presence sensors are basically devices capable of detecting movements of certain bodies.
When the sensor detects any movement, a relay is activated, closing a normally open contact, allowing the passage of electric current and activating a component, for example, in which case a lamp will be activated.
Installing a presence sensor:
We will first show how to install only the presence sensor to activate a lamp, using a motion sensor installation diagram to help in the installation, this connection being similar to the connection of a simple switch.
We alert you to some precautions that are necessary before carrying out any installation, the first of which is to never perform any installation on energized circuits, turn off the general circuit breaker of the installation or turn off the circuit breaker of the respective circuit in which the installation will be carried out, and make sure that it is, in fact, de-energized, so make sure that the respective circuit is not energized during installation.
Installation: presence sensor.
This installation diagram can be used in either 127V or 220V installations, but first, make sure that the sensor is bolt or compatible with one of these voltages. In this connection, it is not possible to light the lamp manually, as only the sensor controls the lamp. In this connection, there is a small expenditure of permanent energy, as the presence sensor needs to be connected to a power source to function.
Presence sensor scheme:
First step: power the presence sensor, so check which are the terminals or phase, neutral and return cables of the presence sensor, after identifying them, just connect each of the power cables to the respective sensor cables presence, that is, phase cable on the terminal identified as phase and the neutral cable on the terminal identified as neutral, It is important to note that if the connection is 220V, simply connect phase 2 to the terminal with the identification of neutral. The image below shows in detail how the presence sensor is to be powered.
Second step: connect the lamp, for this, just connect the neutral cable to the terminal that connects the side of the receptacle, then supply the lamp with the return cable connected to the terminal that connects to the central part of the receptacle. We recommend that the connection be made in this way, so that the risks of electric shock are even lower, both when performing maintenance, and simply changing the lamp.
Installation: presence sensor and simple switch.
As we saw earlier, the installation of the presence sensor is very simple, but unfortunately it is not possible to activate the lighting point manually, that is, only the presence sensor activates the lamp. In this case, it would not be possible to keep the lamp on after the movement that caused the lamp to be turned on. But it is possible to make this happen by simply installing a switch in parallel with the presence sensor.
Presence sensor diagram: With simple switch.
- First step: install the presence sensor and the lamp, in the same way as we taught earlier, taking all necessary precautions. After this connection, a derivation must be made in the return cable and connect this cable that was derived to the first terminal of the simple switch. The image below shows in detail how it should be done.
First step: installation of the presence sensor with simple switch.
- Second step: to perform a derivation, but this time it must be made in the phase cable, then connect this derivation cable to the second terminal of the switch. The wiring diagram below shows how it should be done.
The connection shown above creates an alternative for switching on the lamp via the switch, there are now two ways to switch on the lamp, by movement and by the switch. Maybe you are thinking that, if this happens, there may be a problem, because energy is coming in the return cable, coming from both the presence sensor and the simple switch, but there are no problems with this connection, because the voltage that arrives the lamp is of the same phase, only an alternative path was created.
Installation: presence sensor and parallel switch.
The advantage of this connection is that it saves energy, since the parallel switch will control both the lamp and the presence sensor working in two positions, that is, in one position when the switch turns on the lamp, the switch will turn off the presence sensor , avoiding unnecessary expense, in the second position, when the switch turns off the lamp it will activate the motion sensor, causing the lamp to depend on the presence sensor.
Presence sensor diagram: With parallel switch.
- First step: connect the three way switch, for this we will supply the switch with the phase cable on the central terminal, then connect a return cable to the upper terminal that will be connected directly to the lamp. The lower terminal of the parallel switch will be connected to another return cable, which will be connected to the power cable / terminal (phase) of the presence sensor. See the connection diagram below:
- Second step: connect the presence sensor, connecting the neutral conductor to the presence sensor neutral cable / terminal, then make a derivation in the lamp return cable and connect to the presence sensor cable / terminal, as shown the connection diagram below:
- Third step: this is the simplest one, as it is enough to connect the neutral cable to the receptacle terminal, to the terminal that refers to the lateral contact of the receptacle, remembering that the return cable must be connected to the terminal that refers to the central contact the receptacle. The image below shows how the connection should be made.
If you have any questions about how to install the presence sensor, the video below shows in practice how to make this connection step by step.
We finish one more article here and we hope to have helped to remove all your doubts about how to install a presence sensor! So if you still have any questions or curiosity on this subject, leave it in the comments and we will answer.