Fujitsu VRF issue

[Paulius]

We have a problem with VRF system AYJA126LATF. One master (AYJA126LATF) unit and two (AYJA126UATF) slave units.
Inverter compressor used to make ticking sounds when starting. It used to tick for 2 seconds ant then stop. Few times it tries to start until it shows inverter compressor alarm.
We checked sensors, valve coils, main PCB, inverted PCB, wiring. All was OK. Even compressor wiring resistance was ok. Everything was checked by service manual.
We took some refrigerant samples and in the lab we found out that there was a lot of non condensibles (air) in the system. We decided to change the compressor and fill the system with fresh refrigerant with correct amount.
Compressor started and stopped after one minute. Then it started making same ticking sound as the previous compressor.
After that we decided to change the check valve on the inverter discharge pipe. We thought it was clogged and the compressor was not able to run because of blockage. (added a scheme showing that check valve).vrf.JPG

I add link with compressor sounds:

Any ideas what went wrong? Is the new compressor dead?

[Brian_UK]

Almost sounds like it may be running backwards.

Double check the wiring, also the incoming mains.

[install monkey]

usually inverter pcb has to detect the current draw via ct coils- if the current draw is more or less than the expected current then it will alarm

[Paulius]

Almost sounds like it may be running backwards.

Double check the wiring, also the incoming mains.

Checked the wiring. Everything looks fine. This unit has 2 on/off compressors which work fine.
As we have identical systems I swapped all PCBs of this unit and one that is working fine. The other one works ok with PCBs from the broken one. And the first one makes the same noise and does not start. Although I've noticed that compressor makes same noise with one phase disconnected between inverter and compressor
Is there any chance that we killed this new compressor in only one minute of running? Is it out of oil? Or sucked too much oil?

[nike123]

This sounds to me like scroll running in opposite direction. What is compressor model?
Try to swap two (of 3) wires feeding compressor!

[Paulius]

Checked the wiring. Everything looks fine. This unit has 2 on/off compressors which work fine.
As we have identical systems I swapped all PCBs of this unit and one that is working fine. The other one works ok with PCBs from the broken one. And the first one makes the same noise and does not start. Although I've noticed that compressor makes same noise with one phase disconnected between inverter and compressor
Is there any chance that we killed this new compressor in only one minute of running? Is it out of oil? Or sucked too much oil? Was it defective when we got it?

I rechecked resistance once again and noticed that when measuring between W and U the value is unstable. It should be 0.302 ohm. It rises to ~0,9 and drops to 0,1 until finally becomes stable to around recommended value. That makes sense as I told before that compressor is producing same sound even with W phase disconnected.

[Paulius]

This sounds to me like scroll running in opposite direction. What is compressor model?
Try to swap two (of 3) wires feeding compressor!

Tried swaping wires with no result.
I can't tell the model atm.

[nike123]

I rechecked resistance once again and noticed that when measuring between W and U the value is unstable. It should be 0.302 ohm. It rises to ~0,9 and drops to 0,1 until finally becomes stable to around recommended value.

It looks like some capacitance has measured. Earth third wiring connection and housing while measuring resistance between other 2 connectors.
Check compressor wiring (all 3 connected toghether) against housing with megaohmeter at 500V 1min test! 100 MΩ is required insulation resistance.
For comparing phase winding resistance, you should use wheatstone bridge resistance measurement! Miliohmmeter!
What instrument you have used for your measurments?

[Paulius]

It looks like some capacitance has measured. Earth third wiring connection and housing while measuring resistance between other 2 connectors.
Check compressor wiring (all 3 connected toghether) against housing with megaohmeter at 500V 1min test! 100 MΩ is required insulation resistance.
For comparing phase winding resistance, you should use wheatstone bridge resistance measurement! Miliohmmeter!
What instrument you have used for your measurments?

I am using a multimeter.

[poppypiesdad]

Compressor knackered sounds like a bearing has gone , windings can show nothing .
Or inverter board knackered
Have you checked the board with an inverter checker ?
Have you checked phase rotation on the incoming supply
Have you asked why they bought crap gear in the first place ?

[Paulius]

Compressor knackered sounds like a bearing has gone , windings can show nothing .
Or inverter board knackered
Have you checked the board with an inverter checker ?
Have you checked phase rotation on the incoming supply
Have you asked why they bought crap gear in the first place ?

Inverter boards is OK because I swapped boards with other asame unit and it was working fine.
No I haven't checked with inverter checker because I asume PCB is fine.
Phase rotation is OK.
What do You mean "crap gear"? I don't think Fujitsu is crap.

[hvac_weng]

Hi Paulius. I'm Weng from Fujitsu Malaysia. The compressor which breakdown is constant or inverter compressor? Please check those big capacitor under the inverter PCB.

[hvac_weng]

I just saw the video.judging from the sound. The new compressor is dead. It won't start and keep making those noise. Please replace it.

[Paulius]

I just saw the video.judging from the sound. The new compressor is dead. It won't start and keep making those noise. Please replace it.

Yes I am pretty sure it is dead. The main question is why? Because it was running for only 1minute. Previous one used to make the same sound. Can't figure out why it is dead. Until then I don't want to replace with a new one. Could it be damaged while being transported?
I have ordered vrf service tool so next week I should be able to get more info.