Daikin VRV III Heat Recovery - LC error fault code

[VitorFC]

Hi,

Anyone familiar with the LC error on Daikin VRV outdoor unit?

I'm servicing a Daikin model REYQ12P9Y1B, I've replaced all the boards, tested fan motor and inverter compressor. All connections are good between boards.

I don't know what else to do. Is there any procedure I'm missing? Hard reset?

I've heard there's a rewiring mode but I don't know how to activate it...

Any pointers would be appreciated!

Thank you

Vitor

[PRESS]

Which PC boards did you replace? LC is communication error between inverter PC board and the outdoor control PC board. Chech the following:
1. Fan inverter PC boards
2. Compressor inverter PC board
3. All your inverter PC board wiring
4. Compressor Short circuiting
5. Fan short circuiting
6. Faulty noise filter
7. Faulty PC board

hope this will help.

[PRESS]

With daikin its just a test mode which you run for the master PCB to pick up and configure the rest of the system components. Daikin runs training courses which cover how to run such operations. have you been to one of these courses? You can access the information on the procedure of doing this in the service manual of the unit. If you dont have it let me know I will send it to you. pkatete@gmail.com

[Onsyi]

VitorFC, Take a picture of all the boards and wires. Maybe someone stole the connecting cable.

[martinoff]

LC
80% inverter compressor
20% inverter PCB

definitely in VRVIII you MUST replace them together

here is the troubleshooting
https://app.box.com/s/59bs5i1rib1iopgvlpah

[install monkey]

the rewire mode your referring to is the wiring check function- this needs to be performed if youve swapped the main pcb
check for green flashing led's on each pcb-prooves comms, also check the 3 wire comms cables as the can vibrate out their connections on the pcb, also ensure your mains supply is correct, no loose connections or water ingress

[VitorFC]

@PRESS; @Onsyi; @martinoff; @install monkey

Thank you for all your help.

Now I feel kinda silly but I found that the fan inverter boards are different for MF1 and MF2, they are exactly the same but have different part-numbers.

I was using 2 MF2 inverter boards.

So the malfunction was a fan motor (MF1) and a busted MF1 inverter board.

Well, I still had some difficulty setting the system, but after some fiddling it started working.

Thanks again