Using a Ruuvitag for Cooling Fan Activation in Conjunction with Victron Cerbo GX
When setting up an electrical system in a confined space, such as a van, maintaining an optimal temperature is crucial. Components like power systems can heat up, especially when they’re placed in areas with limited airflow, like under a bed or inside a cabinet.
Why is Temperature Management Important?
Victron Energy equipment, when overheated, starts to “derate.” This means the device’s performance diminishes as the temperature rises. For example, a MultiPlus 12/3000/120 inverter/charger rated for 2,400 watts at 25°C might reduce its output to 2,200 watts if the temperature rises to 40°C.
The best approach is to incorporate as much passive ventilation as possible, ensuring at least two vent points for effective airflow. While there are numerous ways to add vents, sometimes passive cooling isn’t sufficient. In such cases, active cooling methods, like computer fans, can be employed. These fans can be set to activate when the temperature reaches a certain threshold. This can be achieved using a Ruuvitag (a wireless sensor that measures temperature, humidity, and air pressure) and the built-in relay of a Victron Energy Cerbo GX.
How to Connect a Ruuvitag to Victron Cerbo GX
Ruuvitags are compact, cost-effective sensors that can wirelessly connect with a Victron Cerbo GX. They come in various versions, with the baseline model measuring temperature, humidity, air pressure, and motion. To connect a Ruuvitag:
- Activate the Ruuvitag by pulling the plastic strip on its side.
- On the Cerbo GX, navigate to the Bluetooth settings and ensure it’s enabled.
- Ensure Bluetooth sensors are also enabled.
- The Ruuvitag should now appear on the I/O screen or the main menu.
- Assign a name to the Ruuvitag for easy identification.
Setting up a Temperature-Triggered Fan
With the Ruuvitag in place, you can now set up a fan to activate based on temperature readings:
- Choose a 12-volt DC-powered fan suitable for your needs.
- Use relay 2 on the Cerbo GX for temperature triggers.
- Configure the specific temperatures at which the fan should turn on and off.
Wiring the Relay
The final step involves wiring the relay:
- Use the provided black terminal blocks with the Cerbo GX.
- Connect the 12-volt DC positive from your system to the relay’s “common” connection.
- Connect the 12-volt DC negative wire directly to the fan.
- Wire the NO (normally open) connection to the fan’s DC positive terminals.
Once set up, you can test the system by adjusting the activation values or using a heat source on the Ruuvitag. When the set temperature is reached, the relay should activate the fan.