Daikin VRVII RXYQ16

[Peter_1]

I have a client with VRVII's, 2 x (one master + one slave) +/- 9 indoor units on each, controlled by an Itouch installed 2004. Divided in a left and a right part of an office
Problem: 3 compressors, the VFD controlled ones on earth in a period of +/- 8 months, each time another circuit.
What can be the reason?

Present problems: one indoor unit communication error (U8) but it still runs fine. Cause?
How to reset malfunction history..if possible (depress test 4 sec, then again 4 sec and then...?)
Second problem, for some reason, after some time, sometimes 4 hours, sometimes after 3 days, all the units are switched to off. This morning most, not all switched off on R and L part of the office.
Another problem L8 fault (was L9 some weeks ago) but units are running fine sometimes for 5 days and sometimes 3 faults a day (mostly L8)
If we have an L8, why then all the 4 units are shut down an not only the master/slave with the apparent fault?
Can someone give me some light please?

[hyperion]

In order to reset the fault history on the VRV condensing unit, I have been advised by Daikin to press and hold the mode button for 30 seconds and then press the test button. This should completely reset the system. The unit will then go through its 40 minute initiation etc and should then be ready to run as normal.
There was however a small doubt in the techs answer as to whether or not this would work!
Not sure about the other problems, but regular appearance of an L8 code may mean that the inverter compressor is possibly on its way out or maybe just physically becoming overloaded, difficult one to call.

[frank]

Bl****y machine. Just spent 10 minutes typing a reply and lost the lot!!!

Hi Peter

The U8 fault is a transmission error between main and sub remote controllers or a faulty remote controller pcb. As yours is intermittant, I would suspect that you have got some interference on the wiring. Check that it is 2 core unshielded cable and that the cable doesn't run near power cables or high frequency lighting.

To delete the last fault code on a BRC1D controller, press the Test button to bring up the error code and then press and hold the On/Off button until the error code disappears.

The L8 code is a momentary detection of overcurrent in the power transistor:
If 33.5Amps is measured for 5 secs or
if 27.5 amps is detected for 260 seconds

I would guess that your compressor is on the way out.

The L9 error is generated when an abnormal sine wave is detected from the compressor and the compressor fails to start.

The continued loss of compressors makes me think that the pipework may not have been installed with OFN purging or that proper evacuation was not carried out during the original installation.

Have a look on the Daikin extranet for document SiEN37 - 701 which has all of the fault logic tables

[cool#9]

Hi Peter 1 how are you.?

I've had this kind of problem about the L8 fault.
That was a wrong connection on the U/V/W/N connector on the inverter pcb. Check inside the connector and change the whole wire on each unit.

The most important about the compressor is the oil return, you have to change the small filters and capillary tubes from the oil separators.
You must check also the oil line between the 2 outdoor units (1/4 copper tube depending on the series).
On VRVII heat recovery you will have to change some other filters... but i don't know the VRV serie yet.
rgds
cool#9