1. What does the Active P1 Splitter do?
The Active P1 Splitter allows you to connect multiple P1 devices simultaneously to a single smart meter, such as:
- EV chargers
- Wi-Fi P1 dongles
- Thermostats
- Energy managers
Unlike passive Y-cables, this splitter provides:
- Active buffering
- Signal amplification
- Galvanic isolation
This ensures that connected devices never interfere with each other.
2. Contents of the package
- Active P1 Splitter (4- or 2-port)
- Short P1-IN cable (0.5 meter – optional: 5 meters)
3. Safety
- Place the splitter in a dry, cool, and well-ventilated meter cabinet.
- Do not open the splitter.
- Keep P1 cables separate from 230V wiring.
- If in doubt, consult your installer or network operator.
4. Installation – Step by Step
Connect the IN port
Connect the IN cable from the smart meter to the splitter. Use only the included black flat cable.
Check the IN LED
- Blue on = smart meter provides P1 power and data.
Connect your devices
Connect your P1 devices to the OUT ports.
- OUT LEDs blink blue when data is transmitted. (Note: with some dongles, the LEDs may not blink. This is normal; the devices will still function properly.)
USB-C power (optional)
Use a USB-C power supply when:
- The splitter is used with a DSM4 or DSMR2 meter
- Multiple devices are connected
- A device fails to start or stays offline
- The red LED indicates that USB power is active.
Check communication
Ensure your devices are receiving data in their app or Home Assistant environment.
Mounting
Mount the splitter neatly in the meter cabinet.
5. LED Indicators
| LED | Betekenis |
|---|---|
| IN – blue (on) | Smart meter provides P1 power and data |
| OUT – blue (blinking) | Data traffic with the device on that port |
| USB – red (on) | External 5V USB-C power active |
6. Compatibility
The splitter works with almost all DSMR smart meters (v2 through v5+) and P1 devices, such as:
- EV chargers: Alfen, Easee, Wallbox, EVBox, Zaptec, Tesla, NewMotion
- Smart home platforms: Home Assistant, Homey, Domoticz, OpenHAB, Node-RED
- P1 dongles: Smart Gateways WiFi P1, HomeWizard, Iungo, Powerbaas
- Thermostats: Toon, Plugwise, Tado
- PV systems: SolarEdge, SMA, GoodWe, Huawei (consumption + production)
7. Best Practices
- Use a USB-C power supply when multiple devices are connected.
- Keep cables short and tidy.
- Label devices and ports for future maintenance.
- Blinking OUT LED = active communication.
- For EV load balancing: ensure correct P1 settings in your charger.
8. Troubleshooting
Splitter not working / no data
- Check that you are using the included IN cable between the smart meter and the splitter.
- For OUT ports, always use the original cables of your P1 devices.
Devices not starting
- Connect a 5V/1A USB-C power supply to the splitter.
- Smart meters often provide insufficient power for multiple devices.
LED check
- Red LED on? → External USB power is active.
- IN LED (blue) on? → Connection to the smart meter is OK.
- OUT LED blinking? → Data traffic is active.
- Note: with some dongles, the OUT LED may not blink, but the dongle still works.
→ Check the device’s app to see if data is being received.
One OUT port not working
- Try connecting the device to another OUT port.
- If it works there → possibly a defective port → contact Smart Gateways.
P1 dongle not working via splitter
- Try connecting the dongle to its own power supply / USB port (both splitter and dongle externally powered).
Older firmware on devices
- Updating is recommended: Especially Marstek, Zaptec, Alfen, Iungo, HomeWizard may experience issues with older firmware.