Impulse relays, what are they?

Impulse relays are electromechanical devices that, when powered by the nominal network voltage, through the control of pushbutton switches, control lighting points, and it is also possible to control the same light point by several pulse devices. The impulse relay is a technology developed and patented in 1950 by Piero Giordanino and is used until today in the industry, and has been adapted and developed for residential application. In homes, the application of impulse relays can be similar to the parallel or ” Three way ” and intermediate or “four-way” systems that allow the resident to activate the same or several points of light from several switches, which are for their own use of these systems.

Finder impulse relay.

When it comes to the advantages and differences between impulse relays and parallel and intermediate switches (Three way and four-way), we can mention the material savings. For these devices, we can use 0.5 mm square cables for control. Note: The cables used to supply the relay and interconnect with the lamps must be at least 1.5 mm square, in accordance with NBR 5410. The drive components, in turn, are also of a lower cost than parallel and intermediate switches, since only the impulse is necessary to activate the light points. Due to this installation using a reduced volume of cables and a smaller section in the control conductors, this system ends up becoming more economical, with longer durability and with a lower volume of cables in the conduits, thus reducing the risk of overheating the conductors and consequent risk reduction of fire.

Its operation is easy to understand. Inside the device, we have an electromagnetic coil that is activated with each activation of the pulsators, both to turn on and off. The connection of this coil is made as in industrial contactors (A1 and A2), which when powered, the electromagnetic effect transmits the movement through a lever that activates the contacts by turning the lighting points on or off.

The relays, depending on the model, can be supplied with different supply voltages as well as alternating current or direct current, so you must pay attention to the manufacturers’ guidelines in your instruction manual.
Its installation is simple but, as in any activity with electricity, it requires attention, as electric discharge can pose a risk of death to the installer electrician, so update yourself with the norms of the electric sector and follow the guidelines of NR 10 . If you are not a qualified professional, seek guidance and qualification in the area of ​​building electrical. To install the impulse relay you must:

Diagram of a pulse relay connection.

  1. Connect a phase bus cable to terminals 1, 3, and A1 of the impulse relay, if you wish to install two lighting devices.
  2. Then connect a cable from terminal A2 of the impulse relay to terminals A of the pulsators.
  3. Connect a cable from terminal B of the pulsators to the neutral bus.
  4. If using two lamps, connect two cables from terminals 2 and 4 of the relay to the first terminal of each lighting device.
  5. Then connect two cables from the second terminal of each lighting device to the neutral bus.
  6. Finally, check all connections, fit the lamps, test the circuit by energizing the system.
  7. Do not forget to check the seams and isolate them perfectly so as not to close short circuits.

The impulse relay, in addition to providing savings in the dimensioning of materials and energy consumption, allows to optimize the number of different types of actuators, bringing more versatility, flexibility, reduction of labor in the installation and still provides comfort to the user.