Daikin inverter problems

[ronaldo9]

Hi guys

I have a Daikin system , yuk!!!

Master RXYQ14M8W1B
Slave RXYQ10M8W1B

Master unit has a faulty inverter compressor (windings down to earth) , just replaced it and the inverter PCB , after 10 mins of test run got an L8 fault , reset and checked phases going to inverter all balanced but this time it faulted a lot sooner with an L5 fault didn't get a chance to check anything else while it was running , rang Daikin just told me to check gas charge going at that tomorrow. Any other ideas , I did run the system with the new inverter bypassed and the slave unit ran , didn't really perform very well tho but it's inverter didn't fault out. Any ideas ?

[Neddy]

If the slave is still running tomorrow you will know the slave is good and the fault is with the invertor. What was the previous error? I don't think it's gas. Did you recover all the refrigerant, open all the valves when vacing and charge with Virgin refrigerant?Double check all your wiring on the invertor PCB against the slave unit. Have you wired the invertor compressor correctly? Disconnect the wiring to the compressor to check the invertor output using setting mode 2 binary 28. The phases should be balanced. Check your mains voltage to the master unit is good. If all the above is okay I would swap the Master and slave invertor PCBs. If the fault accurs on the slave your new invertor PCB is faulty. If the fault accurs on the master the compressor may be faulty which would be very unusual.

[Asbolute]

Hi guys

I have a Daikin system , yuk!!!

Master RXYQ14M8W1B
Slave RXYQ10M8W1B

Master unit has a faulty inverter compressor (windings down to earth) , just replaced it and the inverter PCB , after 10 mins of test run got an L8 fault , reset and checked phases going to inverter all balanced but this time it faulted a lot sooner with an L5 fault didn't get a chance to check anything else while it was running , rang Daikin just told me to check gas charge going at that tomorrow. Any other ideas , I did run the system with the new inverter bypassed and the slave unit ran , didn't really perform very well tho but it's inverter didn't fault out. Any ideas ?

Ronaldo, how warm was the compressor shell when you began to operate the new INV compressor? One of the biggest issues with VRV/VRF systems irrelevant of the manufacture is that when compressors fail they tend to fail for a reason and this is usually unbeknown to the engineer that has been given the compressor and INV PCB to replace in a day or two, I'd suggest going through the history of the system, the installation, the gas charge, the parts replaced and why, prior to your works, then gather this information and include a visit from a Daikin engineer with service checker to put the system through it's relevant checks, I've known systems to have flow/expansion valve issues but still pass test run and then 3 months down the line you have another compressor failure and a unhappy customer. With an L8 and L5 fault on new INV compressor/PCB i'd look at whether the compressor shell was warmed sufficently and whether the three phase power was correct to begin with.

[frank]

I too always want to know why a compressor failed. It's not acceptable to just apply the change without knowing if the replacement is also susceptible to premature failure.

This doesn't just apply to VRV/VRF but to any system.

Sometimes it is decided that it was not a clean install (OFN purging) or poor evacuation prior to charging, but with VRV/VRF sometimes it is the pipework layout that is at fault (exceeding the maximum distances) which is overlooked by many 'engineers'