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RUNCCI YUN USB to RS485 Converter

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TonyM1958 edited this page Jun 5, 2024 · 28 revisions

NOTE: This page is linked to from the setup wizard. Do not remove or rename!

Summary

The RUNCCI-YUN USB to RS485 Converter is a very cheap RS485 to USB converter.

We haven't had any issues reported when using this adapter.

Connections

See this guide and follow the instructions below when wiring:

  • Stop your inverter by pressing and holding the front panel Enter key. Confirm you want to stop by pressing Enter again.
  • After it stops, remove the Meter/CT/RS485 connector by pressing in the two tabs at top while pulling down.
  • Unscrew the end collar and pull it back to release the cable from the seal. Dis-assemble the connector using the blue H shaped tool supplied with your inverter, and push the CT clamp cable through the seal to expose the connections. Pushing the cable in instead of pulling the connector back reduces the risk of damaging the connections for your CT clamp.
  • Take a suitable length of spare UTP network cable and cut off the RJ-45 connectors on each end
  • Thread the network cable through the Meter/CT/RS485 connector collar, seal and body
  • Strip the outer sheath back about 5cm from each end to expose the wires, taking care not to damage the cables inside
  • The cables are twisted pairs, each with a coloured wire and a white wire with the same colour stripe. Remove about 1cm of insulation from the orange and white/orange wires.
  • Twist the conductors together in each wire separately so they don't splay out as the insert them into the connector. If you can, 'tin' the conductors with solder to make them solid as this will provide a better grip for the screw and reduce the risk of the wire breaking.
  • Cut the remaining wires back at the sheath and tape them to avoid them inadvertently making contact within the connector.
  • Connect the white/orange wire to the 485A pin of the Meter/CT/RS485 connector (pin 4 for H1 inverter, pin 1 for H3 inverter)
  • Connect the orange wire to the 485B pin of the Meter/CT/RS485 connector (pin 3 for H1 inverter, pin 2 for H3 inverter)
  • Replace the Meter/CT/RS485 connector body and seal and tighten the collar, taking care not to rotate or damage the CT clamp or RS-485 cables or connections. Do not plug it into your inverter until you have wired both ends
  • At the other end, connect the white/orange wire to the RS-485 A input on the USB adapter
  • Connect the orange wire to the RS-485 B input on the USB adatper
  • Plug the Meter/CT/RS485 connector in the inverter and restart it by pressing and holding the Enter key again. Wait until it finishes checking and starts normal operation to confirm all is ok.
  • The USB adapter is not fragile but you should protect it and the wires from being accidentally damaged as you may lose your connection to the inverter.

Note: the pictures show the connections for H1 doubled up using orange and blue but you only need to connect the orange / white + orange wires: this leaves you more a bit space so it's easier to insert the wires.

Setup

Simply plug the adapter into a USB port on your Home Assistant host. The device will appear as /dev/ttyUSB0 and will be configured as a serial modbus RTU connection.

Disclaimer: Any information on this wiki is informal advice, and is not supported nor endorsed by FoxESS. There is no warranty expressed or implied: you take sole responsibility for everything you do with your inverters.

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