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Peter_1
18-07-2012, 09:50 PM
Does someone has experience with Daikin VRVII systems, installed around 2006 -2008 where mostly, almost allways the inverter driven compressors in the outdoor unit of the master and slave fails after +/-4 to 6 years of service?
I now know 2 different setups where several compressors (+/- 10 compr.) failed after 4 to 5 years service.

Faults: compressor ran out of oil and blocks due to lack of oil (some compressors only have 30 ml or 300 ml of oil when you open them) or mostly a mass-closure/earth leakage fault.
Some compressors have really black oil in their sump.

What can be the possible causes for these faults? Lines were soldered under nitrogen atmosphere when installed end 2006, there was regulary service on the filters, cleaning of the coils, Y-joints mounted the correct way,...

Is it mandatory to have first the biggest unit on the main suction line and then the smaller outdoor units in a parallel setup? If installed the other way, what problems can be expected?
What's your opinion about the obligation to swap also the Power PCB of the inverter?

install monkey
18-07-2012, 10:08 PM
weve got vrv2 installed on a number of sites and the only problems we've had is refnets fracturing due to long piperuns and linear expansion with pipework clamped with hydrazorb clips too tightly- the odd indoor board failing on u9 comms error,
weve got 3 vrv2 46hp machines and 1 of them is 16hp master 16hp slave and a 14hp slave. again no problems
i remember on a daikin course they did say it didnt matter if the master was the smaller unit or the larger as long as it was within the scope of distance and height of outdoor units

Peter_1
19-07-2012, 06:33 AM
Install Monkey, were those VRVII coupled as Master and slave? Were they installed around 2006-2007? The position of the biggest unit in a parallel setup seems very important (dixit Daikin Europe)

install monkey
19-07-2012, 08:28 PM
the units are 3 systems with master,slave,slave configuration- 16hp master 16hp slave then a 14hp slave- all mounted next to each other with the 1/4 oil line connected between them, ive checked the installation manual and the vrv2 design manual and the only thing refering to outdoor multiple systems is slightly sloping pipework downwards from the slave unit so oil doesnt settle when the slave isnt running
im on site on saturday so i can check when they were installed

Install Monkey, were those VRVII coupled as Master and slave? Were they installed around 2006-2007? The position of the biggest unit in a parallel setup seems very important (dixit Daikin Europe)

frank
19-07-2012, 08:39 PM
Hi Peter

we have several VRVII installs but have not experienced the problems you describe.

We have come across the black oil on R407C split systems though - not ones we installed I may add. We think it happens when the pipework is left open to atmosphere and absorbs excessive moisture, thereby contaminating the oil. The black oil seems to be acidic.

install monkey
19-07-2012, 08:58 PM
peter if you buy an inverter compressor and not the inverter then you will not get 12 month waranty,also i recommend buying the oil change kit- as your meant to syphon the oil out the other compressors too.

Peter_1
19-07-2012, 09:03 PM
feedback to help in any way is very important at this moment.
I personally have a client where 6 parallel VRVII systems (so 12 VFD controlled compressors and 24 on/offs) are installed and we changed already 4 compressors in 1,5 years. All systems hydraulic independent from each other.

El Padre
01-08-2012, 10:10 AM
Hi Peter,

Does the client leave the system running under minimal load conditions frequently? I had a system a few years ago where the client had one server room being cooled by the comfort cooling VRV system, after a few compressors were changed they installed a dedicated high sensible cooling unit in the data room.

As far as I am aware that has solved the problem, I drilled a hole in the bottom of one of the failed compressors and about three drops of oil came out.

Cheers

Peter_1
02-08-2012, 06:33 AM
El Padre, were the units also from around 2006-2007? I see you changed also some compressors: were those the VFD ones in these units? There seems to be not that much problems seen the posts. Frank had no problems at all. What botters me is that Daikin now recommends that the whole system of 5 yeras old needs to be dismantled/removed and a new VRVIII has to be installed.They say thta the contaminated system will never work 100% in the future. How, we refrigeration techicians then handle this kind of problems when we have a severe burnout? I had once as system with probably 10 l water in a pack (combined cooling and freezing) and the system is still working very well despite all the recommendatiosn we got from Bitzer. We may not forget a compressor is only a pump and the lines simply tubes and the only problem we ca have are impurities blocking certain components. But for thsi , they have invented filters. So removing the whole unit is not an option for me due to a burnout or a broken compressor. If a broken compressor or a burnout leads according to DAikin always to a complete dismantling of a whole system, then the system must be better protected.

El Padre
02-08-2012, 01:37 PM
I would guess sometime between 2005 and 2007, most of the failed compressors were the inverter driven ones, problem was more of oil return than of contamination, I agree regarding the fact that the system can be cleaned up, I repaired a chiller with a split evaporator a while back, cost the client about 20% of a new chiller.

There must be something causing this to happen, has anyone datalogged the system with a service checker?

Cheers

Neddy
02-08-2012, 04:55 PM
I've changed invertor compressors on stand alone VRV II. One only lasted 12hrs which was due to a particularly blocked strainer and EEV in the outdoor which was the result of not using OFN when it was installed. It has a brand new discharge sensor which didn't cut it out on safety and it cooked itself. These units do not have a compressor shell sensor which I think they should do as I I've measured 100 degrees celsius on the top of the shell of one compressor (Suction Side) and it was still running.Also when the compressor failed no fault code came up on the controller. ( not the first time this has happened either)Found The invertor board was trying to give a voltage out every few minutes but the compressor had damaged it. Fitted a new compressor, invertor board and burn out drier and it's still running.

cool#9
05-08-2012, 11:29 AM
Hi Peter_1
I've in my area a long experience about daikin's products, since 1986...
We have a lot of compressor failure since the vrvii series, commissioning date about 2003, we've change roughly 30 inverter compressor in 2009...
The main problem is about the oil return also on vrviii series.
We met problem with filters at the common suction pipe on both 2 and 3 pipes model (see pictures).
We've change a lot of pcb with faulty oil return relay on P series.
We've change a lot of pcb from p7 to p9 series because of poor oil return operation (sotware problem)
The new hr REYQ / REMQ_P series "doesn't like" to work under the right refrigerant charge. If not it leads to poor oil return too.
Also it is necessery to increase the inside demand once a day at maximum load in cooling mode ( it's easier at night driven by i touch controler ).
Sometimes we had fvc68d oil in the system but there's no litterature on it...
rgds
cool#9

Peter_1
15-08-2012, 07:29 AM
Cool9, just noticed your answer now. I'm extremely thankful for your reply, you have no idea how important your answer will be. Have you opened some of the erratic compressors you removed and did you ever found out why the oil return system failed. What did Daikin say abouth this?
Have you read also my other questions in the same Airconditioning section, all related to the same problem? I remember from previous posts you have a lot of experience with Daikin.

bobjob
19-12-2012, 10:43 PM
Hi Peter and others

I am in the same boat now with a VRV 11 system.

The system was fitted in 2004 and is a Heat Recovery size 20 ( 2 x REYQ10M 7WIB)

In November the master unit inverter compressor failed and was found D.T.E.

The customer wanted heating, so I coded out the master module and the system was left running on the slave module. and we quoted for a replacement compressor and inverter PCB etc etc

The customer did not do anything untill 3 weeks later the slave module fails - inverter compressor again DTE and inverter PCB (inverter PCB blown apart and tripped the main circuit breaker for the unit)

Now the customer wants everything done quickly because they have no heating in the building.

I have removed the master inverter compressor and it seems that it has been running very hot due the discharge pipe melting the compressor jacket !
compressor oil is not acidic and we removed around 1.4litre of oil from the compressor.

However there is no oil in the slave inverter compressor, (just enough to check for acidity which is OK)

I have checked the oil separator filters etc all Ok

But were is the oil?

The customer is pressurizing us to get the unit running to give out some heat, so
I have fitted both compressors, master inverter plus slave inverter compressor and new PCBs and I will run up and try and monitor conditions.

Can anyone give some pointers to where the oil for the slave compressor is ?


Regards

Bob

install monkey
19-12-2012, 10:54 PM
probably in the lowest indoor unit- u need to check the oil return procedure when its running- ive had 3 48 hp systems running- all 3 have had pipe fractures and lost oil when it dropped 50kg r410a was repaired- oil wasn't topped up- still working.check to oil separator- lil hole may be clogged

jedijono21
22-01-2013, 12:20 PM
Hi guys, I'm finding this thread very interesting as I've experienced these problems. All with vrv2 reyq installed with a master, slave 1, slave 2 scenario.
Always inverter compressor that goes. I've found that when its gone DTE its usually damaged the inverter pcb, also the DTE cases I've found that when I've reclaimed that the system is short on gas, had a few fractured refnets too.
In my most recent case the fault kept on taking the three phase breaker out. A "handyman" onsite kept on resetting the breaker every morning......handy eh!? The damage it caused to the inverter pcb and also the fan inverter board was unbelievable, needless to say it all had to get replaced and it was very expensive. I've probably changed around 10 or so inverter compressors on this site and I bet there's more to come. I've gone off track with my boring stories now but if anyone else needs anymore info then let me know.

Peter_1
22-01-2013, 04:30 PM
This seems a range with some problems and we all can learn more about this. Especially if you have found or tried specific things.
I'm sure every manufacturer has sometimes his owm specific problems (remember Toyota who called back a guge range of cars) This can happen and. But as long as the manufacturer takes its responsibilty, then I don't see any problem. It changes a lot when you're blamed for these problems like happened once to me with my car with a very specific problem.

redroge
22-01-2013, 06:43 PM
I was told by Daikin that if one unit is disabled the other should not be run for more than three days as the oil will migrate to the dead unit, thus putting the other inverter compressor at risk of failure.

RusBuka
22-01-2013, 07:01 PM
If the inverter in VRV2 that afterwards dies at once PCB dies. Because electronics ****. And in a contour usually by this moment too green ****. It is stupid to change PCB and compressors doesn't help. It is necessary to wash away all contour from green oil.

cool#9
23-01-2013, 10:38 PM
This seems a range with some problems and we all can learn more about this. Especially if you have found or tried specific things.
I'm sure every manufacturer has sometimes his owm specific problems (remember Toyota who called back a guge range of cars) This can happen and. But as long as the manufacturer takes its responsibilty, then I don't see any problem. It changes a lot when you're blamed for these problems like happened once to me with my car with a very specific problem.

Hi Peter 1 how are you?
Well in our area it's a boring problem with Daikin they have a wide range of product they are well known..a lot of distributors..etc.. But they do not take responsability with theirs problems / let's say our problems!!!
Everybody knows about Daikin that they are not enough reliable now comparing to...10 years ago.
I think DENV are not aware about the field complains or maybe they don't know their ESV are unknown?
Cool#9

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