FROM SENSORS TO BUILDING CONTROL SYSTEMS: SIGNALS TRANSFER VIA PCB TERMINAL BLOCKS

Sensors are essential for optimal energy-efficient climate monitoring in buildings. They measure temperature, humidity and many other variables, helping maintain a pleasant atmosphere. Powering sensors and passing on measured values in the form of electrical signals requires the right PCB connection technology.

What do Berlin’s KaDeWe department store, the Nymphenburg Palace in Munich and the “Princess Elisabeth” polar research station in Antarctica have in common? They all use intelligent room automation sensors from Thermokon, a manufacturer of sensors and sensor systems from Mittenaar in Middle Hesse, Germany. For more than three decades, this company has stood for expertise in upgrading intelligent buildings. Its sensors reliably record variables like relative humidity, air quality, temperature and brightness, serving as the basis for energy-efficient climate control in buildings.

Wiring at the Signal Level with the picoMAX® System

Compact design: up to 30 % less space
Convenience and ease: in-hand wiring in difficult-to-reach locations
Connection in series without pole loss: the number of clamping points can be expanded as needed

Sensors: The Sense Organs of Buildings

Sensors function as a building’s sense organs and can be found there in the hundreds. In most cases, you hardly notice them – mounted on the exterior facade, up high right under the ceiling or inside ventilation ducts – in shopping centers, airports, office buildings and hotels. They monitor external variables like humidity, air quality, temperature and light intensity, convert these physical or chemical properties into electrical signals and pass them on to the control system, helping building operators optimize the quality of interior spaces. Thus sensors are an important interface between the environment and the building automation.

For a sensor to function properly, it needs a reliable PCB terminal block that powers the device and transmits the measured values in the form of electrical signals. In most of its sensors, Thermokon uses WAGO’s pluggable picoMAX® eCOM PCB terminal blocks as the interface between the building control and sensor.

The picoMAX® Pluggable Connection System for Easy Wiring

picoMAX® is a compact pluggable connection system that makes dual use of the contact force from a single Cr-Ni stainless steel spring to both clamp the conductor and connect the header pin. This makes picoMAX® even more compact than other pluggable connection systems. The planning for the PCBs can include picoMAX® as a conventional pluggable connector and picoMAX® eCOM as a pluggable PCB terminal block.

Thermokon and WAGO have worked in close collaboration for about 20 years. So when developing its current sensor product line, Thermokon put WAGO’s pluggable connectors on its short list of options. “We printed the prototypes for our sensors on a 3D printer and installed various terminal blocks in them. Then we gave them to installers, who installed and tested the sensors. After evaluating these tests, we concluded that picoMAX® was the best choice for our application,” says Dominique Alt, Head of Product Management at Thermokon, describing the decision to use WAGO’s pluggable connector

Making PCBs Pluggable

Thermokon uses picoMAX® eCOM in most of its sensors. This version foregoes the pin housing – the female connector is soldered to the PCB like a conventional PCB terminal block. The difference is that the terminal block can still be removed like a pluggable PCB connector, allowing in-hand wiring, so the PCB is directly pluggable. Thermokon chose the 3.5 mm and 5.0 mm pin spacing models – using a straight or angled variant according to the specific application.

One Clamping Point for Each Measured Value

Thermokon offers sensors that measure humidity, temperature and air quality, as well as all-in-one solutions to cover all measurement fields. That way, the right sensor is available for installation in every application. “The more measured values we have, the more clamping points we need,” says the product manager. The terminal blocks have from two to six clamping points, so all measurement fields can be covered. Installers can insert solid and fine-stranded conductors with ferrules directly into the terminal block via Push-in CAGE CLAMP® connection. As a general rule, picoMAX® can even be connected in series without pole loss, so the number of clamping points can be expanded as needed.

Since the sensors need to reliably record and transmit measured values in locations around the world, from Antarctica to desert areas like Oman, the PCB connection technology also has to be able to handle these different climatic zones. picoMAX® has a limit temperature range from −60 to +100° Celsius, so it can withstand both heat and cold.

“We’ve always used WAGO terminal blocks – occasionally at first, and now as our standard choice. We already enjoy a great collaboration, so the advantages of picoMAX® were just the icing on the cake, making everything fall into place” says Dominique Alt, speaking highly of the partnership with WAGO. “The trend is toward multi-sensors, so we’re currently working on ceiling sensors of this type. For these too, we intend to rely on WAGO,” says the Thermokon product manager, describing some upcoming plans.

SPE – Data Transfer with a Single Wire Pair

To make buildings and room automation even more intelligent, some PCB terminal blocks and pluggable PCB connectors like picoMAX® offer are SPE-capability. SPE stands for Single Pair Ethernet, a type of data transfer. It simplifies communication and allows data to be passed from the field level to the cloud. In contrast to conventional ETHERNET, SPE requires only a single pair of conductors and is standardized by the IEEE. This new technology has the potential to reduce the number of network transitions – ideally making seamless IP communication possible.