Daikin vrv compressors problem

[a/c.king]

To all field m8s
pleas am looking for some one to help me figer out what is wrong with a vrv system that i rgolary look after.

3 months ago i hade proble with one of the inverter compressors on daikin vrv reyq48myib err code (l8) all repair unit back to normal. After 2 weeksfrom replasing first compressor the second invertoer comp fail. Replase it all back to normal. 2 weeks after theard inverter comp fail. Replased it all back to normal. 1.5 month after replasing the theard comp the first one fail again. Then i start looking at somthing on system killing my compressors. Mostur,acid,oil contamination,refrigerant contamiation..... All resolt show the system isclean and helthy. Then replased the compressor again but this time i regased the system with new refrigerant. During test operation disscharge pressure 330psi at 28c ampent suction line pressur 130psi suction temp 16.5c to17.5c supply air temp 14c return air temp 24c+25%frishair at 28c unitsemsrun ok but there issomthing make meconsern liquid pipe temp at one of the uits its to low 20c i can feel thepipeis coold. Please if there any one exprience same problems with daikin vrv and he solve them out all will apprciated his help

[james10]

Did you replace the inverter boards at the same time it is a possibility that the boards are damaging the compressors check out Daikin extranet for the manuals which include the test procedures for this board it might also be worth monitoring the power supply to make sur your not getting power spikes

[a/c.king]

thax m8 i approciate your effet but othing wrong wit all 3 inverter PBC on the system all resistors are tested and showig fine resolt

thax

[jbomba]

4 way valves could be shot bypassing discharge straight into the suction line hence your high suction pressures. Feel the suction line temp to compressor see if you can feel any heat in it

[stufus]

Did you check the amount of oil in each compressor that was removed,you could have oil return issues.
To drop 3 compressors like that is very unusual.You need to check all solenoids are doing what they should be when required.Check the suction and discharge sensor information against actual gauge readings.A faulty discharge sensor reading higher than actual will cause the system to bypass lp to hp and unload compressors in a repetitive cycle .
Cheers
Stu

[brunstar]

i would check that there is not an oil problem, the other thing that could cause you an oil problem is that if the liquid injection is not closing off, this can flush the oil out of the compressor and cause damage too.

[a/c.king]

thx for all
I recalculate the refrigerant charge and found the system was operating on low refrigerant charge because of oil leak for all five FCU'S. also all three copressors were dry (no oil). Oil een added rfrigerant replaed and charge is now 64kg 410a it was 52kg. one off the pressure trnsduser onHP sid was fauly replaced this one as wel. system running at much batter temp and pressure Dikin engineer inspected system and he was happy from the operation. but am still to worry about this new compressos going down again. reson why
1-when inverter compressors runing by itselfs the section line untell the unit inlet is 11C BUT when it reach the compressor its about 16C i undrstand its subcoling the liguid line but not 5k
2-when any STD compressor start the suction linewill ice up on the INVERTES AND THE STD COMP?


so i dont know guys if the system is healthe as the gauges and the relation between pressure volt as chart shpwing


sorry for bad spieling
my keybaor is rubish LOL

A/C KING

[brunstar]

you may have a blocked suction strainer, this is worth a check by the sounds of symptoms that you are giving.

hehe is your keyboard a qwerty keyboard or has somebody pulled all of your keys off and put them back in a different order..heeh

[a/c.king]

thank u brunstar and allother m8s
1st think its my keyboard.the nobs been pulled out by my 18months sun. i replaced the kyboard and after one month he did the same for the new kyboard so am not bothered to replace it again tell my sun grow up sohe will not pull the letters again LOL.
I will defintely look at what u siad but i dont know if REYQ16MY1B hase one(strainer) on the suctio line. i know there is 3 discharge filters on each compressor line so all togather on REYQ46MY1B will be 9. but if we asuming that the problem is with suction strainer or oil return----- why then only inverter comp going down. in each system there is 3 comp each one has its own oil saparetor and the all linked with the other units on oil equliser line .
i have DAIKIN SERVICE CHECKER I will hok it to the system and se how we go.


all update u all if any think happin

thank u guys

[stufus]

Generally the first comp does the most hours. First start, first comp on, low load duty compressor. The refrigerant velocity in a vrf system is usually sufficient for adequat oil return from indoors and pipework. I make a point of running all systems flat out in cooling for at least an hour during maintenance visits. And check oil levels before and after. If i understand your last comment correctly compressor number1 has failed 3 times and been oil free on removal each time. If so you've got a blockage in either your oil return line, oil equalizer line or your oil return solenoid is not opening the valve. Energised does not mean open.
Cheers
Stu

[a/c.king]

dear stu
when u sayig 1 comp 3 time do u mean 1comp 3time on the same condansing unit? beause my system run on 9comp 3inverter compressors and 6 are 3phase normal compressores and all 9 compressors are scrolls. there for there are three condansing uits link to each others. each uit has 1invertercomp ad 2 3phase copm. the prolem accures ony on the inverter compressors in all three condasing uit ot only in one. hopfuly this make it more clear.

[stufus]

Ok got it ,you have three condensers linked together each condenser has three comps ,one inverter and two DOL.
And you've lost the inverter in each condenser.
I don't do a lot with Daikin myself but a three pipe system is a three pipe system.
I'll have a dig around for some info on the Daikin control strategy.
Have you had all 9 comps running together under load ?
Under partial load does the system continuously cycle on the inverter compressors only.
I'm a bit stumped to be honest .
A bit obvious !! but are all valves on the interconnecting oil line open condenser to condenser...
Cheers
Stu

[brunstar]

now i see that you have a lot of units connected together, what i think you need to do is draw up a diagram as to how the pipes run between the units, is there a level difference between the outdoor units?
What is the length between the first ref net and furthest fan coil?
This is what could be causing the poor oil return.

[RJKing]

Check one of the strainers had not disintergrated and jammed open a solenoid valve. Sounds similar to a fault I had on a VRVII. You can hear is hiising with a screw driver to your ear.

[sunilkumarhvac]

Hi a/c King
I had a similar problem(three inverter compressor failure in series with in a limited period of two months) with daikin vrv-2 unit 30 HP system(RXYQ10MY1K @ 3 units) so can you please share what was your fault and what you did finally for the rectification.

[jbomba]

so you have ice build up on the suction lines leading to each inverter compressor?. Do you no much about the install ive heard of lots of vrv systems turning into expensive paper weights due to engineers not purging with nitrogen when welding.

[sunilkumarhvac]

Hi
I never found any ice build up in that particular system, but I don't have any idea about the series failure reason. Installation was done properly with nitrogen bleeding brazing and as per daikin piping recommendations. I am still waiting for a replay from somebody whom should experienced the same.

[a/c.king]

hi all
again am coming back with bad news after 4 months from replacsing the theard set of compressors. last week one of them fail and units keep triping on E3. i com to conclusion that Daikin VRV III ARE RUBIS.
when systm is runing its working perfict. i am looking to hok my service checker on to see what hell isgoing on.
by theway i have got daiking engineer to look at the unit and hed could not figerout why this happning.

sunilikum
tell me more about your problems with thes machiens????
am happy to share exepiriencewith u.

[stufus]

I think E3 is a HP trip
It sounds like you have either an oil return or flood back issue, have you checked the capacity control valves for the heat exchangers in the outdoor if Daikin use them.
Plus overcharged is a possibility along with hp sensor
Cheers
Stu

[frank]

I don't think it's proper to rubbish the kit based on one particular install that has problems. We have many sites with VRVIII systems without problems, so there must be an inherent fault with this particular system.

It may have something to do with the install, i.e. no nitrogen purging, insufficient vacuum procedure, excessive pipe runs etc.

I think that you should maybe get to the root of the problem before just blaming the manufacturer.......

[install monkey]

u stated previously that u calculated the charge-afterwards did u perform the auto charge function?how much additional did it take?
also are all the units switching off at night ?ie is one indoorstaying on all night thus less than 20% operating causing the compressor failures

[a/c.king]

I preformed additional charge procedures by DAIKIN service book, the calculationI made was 3kg short by Daikin engineer!!!!!!!!!!!!!!!! I don’t thing that 3kgit would made big deference but I added them after with additional charge proceduresin place. Units running 24/7 nonstop butamazingly now with one unit out of its comp and the other one tripping on E3the master unit coping up with the load. I have strong feeling that one or twoof the one way valve on the inverter comp not working 100% properly this time Iam going to check it before i install new comp. the unit with E3 fault itsworks normal when I star the indoors one at the time. but when i select START ALLfrom intelligent controller then the unit go on E3 FAULT. DAIKIN was talkingabout contamination on the system but we did refrigerant and oil test and allcome good. So it’s must be something obstructing refrigerant flow. Or bypassingrefrigerant where it shouldn’t be. by installing the service checker on Monday I’llsee what is happening and hop will figure out what causing this problem and fixit for good and hop that will be reference for other flow mate on trade.

Regards

a/c king

[a/c.king]

Dear stufus

I totally Agree with u that there the system is over charged, when I did theadditional refrigerant requirement calculations I come up with 58kg for thesystem depending on liquid line from unit to BS UNITS 50M RUN and from all BSUNIT to all INDOOR unit 48M. when reclaimed refrigerant was only 52kg on thesystem(I did mode 21) the installer am not sure if its JEC OR MMM AIRCONDITIONING the specify 20kg additional refrigerant for circuit, so20+(14.4x3)=63.2 so I flowed the installer instructions even if I was happywith 58 but 58 to 63 it’s not going to make big impact on system, but letter onDaikin Engineer come up and checked system and he said system wringing verynormal but we might need to add another 3kg ridicules, but I did it system wasworking for 5 months as good as new but only thing was concerning me was theicing up suction line. just last week when I have the slave 2 unit invertercompressor on look out fault, and right after that every 2 days system go’s onE3 FAULT and when I check where the fault is accruing it tells me on slave unit1 after reset. System work’s good for another 2to 3 days. I rely don’t havemuch time to muck around with it this week so I’ll keep it for next week forfull strip out and check ins and outs.... fingers cross

Regards

a/c king