Configure Victron Cerbo GX Tank Level and Temperature Sensors

Key Takeaways

• The Victron Cerbo GX provides four dedicated inputs for resistive tank level sensors and four for temperature sensors.
• Accurate tank level readings often require calibration, especially for tanks with irregular shapes.
• Temperature sensors have specific wiring polarity that must be followed for correct operation.
• Always consult the official Victron Cerbo GX manual for detailed connection diagrams and configuration procedures.

How do I configure tank level and temperature sensors on my Victron Cerbo GX?

The Victron Cerbo GX allows direct connection and configuration of up to four resistive tank level sensors and four temperature sensors through its dedicated inputs. Configuration involves selecting sensor types, calibration, and setting display units within the Venus OS menu, enabling comprehensive monitoring of your system's fluid levels and temperatures.

Setup and Configuration Steps

The Cerbo GX (models BPP900450100, BPP900450110, BPP900451100) operates on an 8 - 70VDC power supply. Before beginning any physical connections, ensure the Cerbo GX is powered off and disconnected from all power sources.

Step 1: Physical Connection for Resistive Tank Level Sensors

The Cerbo GX has four resistive tank level inputs.

1. Identify Inputs: Locate the four tank level inputs on your Cerbo GX.
2. Connect Sender: Connect your resistive tank level sender to one of these inputs. The manual does not provide specific wiring diagrams for resistive tank level senders, but the general connection method involves connecting the sender's signal wire to the input and its ground wire to a common ground point.
3. Sensor Type: The Cerbo GX supports resistive tank level sensors with standard ranges such as European (0-180 Ohm) and US (240-30 Ohm), and custom ranges up to 0-300 Ohms (available with firmware v2.80+).

Step 2: Physical Connection for Temperature Sensors

The Cerbo GX also has four temperature sense inputs.

1. Identify Inputs: Locate the four temperature sense inputs on your Cerbo GX.
2. Prepare Sensor Wire: If using a Victron temperature sensor (e.g., ASS000001000), ensure the sensor wire has either a ferrule or at least 10 mm of exposed copper for proper contact within the removable terminal block connector.
3. Connect Sensor: Connect the temperature sensor to one of the inputs, observing polarity: the red wire connects to the top terminal, and the black wire connects to the bottom terminal.
4. Sensor Range: These sensors are designed for a temperature range of –40 °C to +70 °C.

Step 3: Accessing Sensor Settings on the Cerbo GX

Once physical connections are complete and the Cerbo GX is powered on:

1. Navigate to Settings: On the Cerbo GX display or via a connected device (e.g., VRM Portal, VictronConnect), navigate to the main menu.
2. Select Integrations: Go to Settings → Integrations.
3. Tank and Temperature Sensors: Select Tank and Temperature Sensors to access the configuration options for your connected sensors.

Step 4: Configuring Tank Level Sensors

For each connected tank level sensor:

1. Enable Sensor: The manual does not detail the process for enabling or disabling temperature sensors in the Settings → Integrations → Tank and Temperature Sensors menu, but ensure the sensor is recognized.
2. Select Standard: Choose the resistive tank sender standard that matches your sensor: European (0-180 Ohm), US (240-30 Ohm), or Custom (0-300 Ohms).
3. Set Tank Volume Unit: Select your preferred unit for tank volume: Cubic metres, Litres, Gallons (US), or Gallons (Imperial).
4. Define Fluid Type: Specify the type of fluid in the tank from options such as Fuel, Fresh Water, Waste Water, Live Well, Oil, Black Water (sewage), Gasoline, Diesel, LPG, LNG, Hydraulic Oil, or Raw Water.
5. Configure Alarms: You can configure and activate separate low or high-level alarms for each tank sensor. The manual does not provide specific instructions for this process.

Step 5: Calibrating Tank Level Sensors

For non-linear tanks, calibration is crucial for accurate readings:

1. Access Calibration: Within the tank sensor settings, look for calibration options.
2. Custom Shapes: The Cerbo GX supports custom shapes for non-linear tanks, allowing up to 10 variations to be defined. This helps map the sensor's resistance output to the actual fluid volume more accurately. The manual does not outline detailed calibration steps beyond this.

Step 6: Configuring Temperature Sensors

For each connected temperature sensor:

1. Enable Sensor: Ensure the sensor is recognized and enabled. The manual does not detail the process for enabling or disabling temperature sensors in the Settings → Integrations → Tank and Temperature Sensors menu.
2. Select Temperature Unit: Choose between Celsius or Fahrenheit.
3. Set Sensor Type: Define the sensor's application: Battery, Fridge, or Generic. The manual does not provide specific instructions for assigning a custom name to temperature sensors.
4. Apply Offset: An offset can be applied to correct the temperature reading if needed.
5. Adjust Scale: The scale can be adjusted using a multiplier between 1 and 10.

Step 7: Monitoring

After configuration, tank level and temperature data can be monitored directly on the Cerbo GX display or remotely via the VRM Portal. The manual states that tank level data is sent to the VRM Portal. The manual does not provide specific instructions on how to access the "Levels button" for a graphical overview of tank levels.

Common Configuration Settings

The Cerbo GX offers several configurable parameters for tank level and temperature sensors to ensure accurate monitoring and display.

NMEA 2000 Tank Senders

The Cerbo GX can also integrate with NMEA 2000 tank senders, provided they transmit PGN 127505 (Fluid Level). These senders should have a Device Class of General (80) with Transducer (190) or Sensor (170), or a Device Class of Sensors (75) with Fluid Level (150). Some NMEA 2000 senders, such as the Maretron TLA100, allow fluid type and capacity configuration directly via the GX device menu. The manual does not provide information on how to physically connect third-party NMEA 2000 tank senders to the Cerbo GX, beyond mentioning the need for a VE.Can to NMEA 2000 cable or OSUKL adapter.

Safety

Always ensure the Cerbo GX is powered off and disconnected from all power sources before making any physical connections to sensors. Incorrect wiring can damage the device or sensors. When working with tank level sensors, especially for fuel or other hazardous liquids, ensure proper ventilation and follow all safety guidelines related to the fluid type.

When to call a technician instead

If you encounter persistent issues with sensor readings after following all configuration steps, or if the Cerbo GX does not recognize your sensors, it may indicate a hardware fault with the sensor or the Cerbo GX itself. In such cases, or if you are unsure about any wiring or configuration steps, contact a qualified Victron Energy installer or technician. Attempting repairs or modifications beyond the scope of the manual may void your warranty.