Daikin VRV -III Compressor Failure

[MrDom]

Ok, 12 months ago I assisted in commisioning 14 VRV - III systems serving a hotel building. And during the commisioning we found that a system had tripped its breaker and upon investigation we found that one of the systems Master Compressor (Inverter) had seized and also blown the Inverter Board.

At the same time a different system also had the same problem.

We organised replacement parts under warranty, and replaced both compressors in the same day. Both systems had been runnning for several weeks as we commisioned the other systems ready for filling out commisioning sheets etc.

The second system we had fixed again tripped its breaker, and we then found that a second compressor had gone down.

This gained the interest of Daikin after a phone call from our Supervisor, Daikin took the compressors away and took oil samples to investigate any contamination which might have caused the fault.

They reported back that there was a high moisture content in the oil, which was true but not due to incorrect Vaccuum being acheived.

I informed my supervisor that both compressors where replaced whilst it was raining and instead of sealing the compressors straight away we concentrated on getting both systems back up and running.

We took some refrigerant samples to get them tested at United Refrig, they found that any moisture content within the system was low.

Now a year later the first system we changed a compressor on has seized, aswell as completely different system on the same site.

These where fixed in the last two weeks.

Having given the above details has anyone else come across VRV -III systems falling over in the same way?

[VRVIII]

Hi,

This sounds like a result of liquid charging suction or dual purpose (discharge) lines, from a vac or when operating. This can either break the scroll then a broken fragment falls into the motor causing a short to earth or cause damage that isn't always apparent.
It might be worth having a look at this previous thread http://www.refrigeration-engineer.com/forums/showthread.php?t=22623

Are the systems heat pump or heat recovery?
How did you charge the systems?
How did you reclaim, press test & charge when replacing compressors?
Were the systems tested monitored during commissioning & after replacing compressors?
What was the quantity & condition of oil removed from faulty compressors?
How long were CCH left on with F1F2 comms to indoors?
Do they carry out generator or fire alarm tests? How are the systems shut down?
Have you you checked for crossed wiring/piping between systems etc?
What fault codes are stored in controller history?
What are the pipe run lengths from outdoor to furthest indoors?
Were any of the systems commissioned/installed in stages?

Liquid pumping could be caused by a faulty component or sensor but it’s very unlikely this is the case in so many different systems. I have commissioned various large VRV3 sites over the past couple of years, none of them have dropped a compressor.

[MrDom]

Are the systems heat pump or heat recovery?
Systems are Heat Pump

How did you charge the systems?
Charged into the liquid line

How did you reclaim, press test & charge when replacing compressors? Reclaimed gas from all sides of system, via the usual method, leak tested all brazed joints, also purged system when brazing new and old compressors.
Were the systems tested monitored during commissioning & after replacing compressors?
Yes, the systems where ran in full heating after they where charged, as the customer required them up and running in heating mode due to guests arriving at the hotel.
What was the quantity & condition of oil removed from faulty compressors?
Unknown
How long were CCH left on with F1F2 comms to indoors?
CCH? I dont know what that means sorry
Do they carry out generator or fire alarm tests? How are the systems shut down?
Fire alarms yes, wired into the Dbacs I beleive, No Generator in use. Systems are shut down via Dbacs as required.
Have you you checked for crossed wiring/piping between systems etc?
The systems have been running for the last twelve months after commisioning, all units have been test ran, one at a time to confirm that each individual unit runs in heating and cooling as required. All PC/ADD ahve been checked and double checked throught commisioning and paperwork.
What fault codes are stored in controller history?
The last two system failures where JA/E5 faults, on seperate systems.
What are the pipe run lengths from outdoor to furthest indoors?
I think around 300m but I cant be sure I dont have commisioning sheets to hand right now.

Were any of the systems commissioned/installed in stages?
Yes.

[multisync]

What has Daikin had to say about these problems?

[VRVIII]

How did you reclaim, press test & charge when replacing compressors? Reclaimed gas from all sides of system, via the usual method, leak tested all brazed joints, also purged system when brazing new and old compressors.
Did you use the correct refrigerant reclaim (mode 2 setting 21) when reclaiming/evacuating? This must be used or O.F.N from press test can be trapped, leaving the system contaminated.



Were the systems tested monitored during commissioning & after replacing compressors?
Yes, the systems where ran in full heating after they where charged, as the customer required them up and running in heating mode due to guests arriving at the hotel.
Did you test the systems using a service checker or have Daikin not attended site and checked the systems?

What was the quantity & condition of oil removed from faulty compressors?
Unknown
When you remove the faulty compressors you could drain the oil to check quantity & condition as this may help give an indication to what's happening.



How long were CCH left on with F1F2 comms to indoors?
CCH? I dont know what that means sorry
Crank case heaters



What fault codes are stored in controller history?
The last two system failures where JA/E5 faults, on seperate systems.
Did you establish the reason why the HP transducer & HP faults had occurred?



What are the pipe run lengths from outdoor to furthest indoors?
I think around 300m but I cant be sure I dont have commisioning sheets to hand right now.
The max run length for the system is 165m, one way length from outdoor to furthest indoor.



Were any of the systems commissioned/installed in stages?
Yes.
Do you know how this was done? I've seen problems when a system is operated with some indoors piped but not wired etc.