Daikin vrv3 "super inverter" fault.

[mupdook1]

hi guys, this is my first post on here although i have been a keen reader for some time now. i am fairly new to the wonderful world of A/C so i hope you'll go easy on me. anyway here goes:- at one of the sites i look after we have a Daikin VRV3 REYQ14P8Y1B Super Inverter which supplies 9 indoor fan-coils. each indoor unit has its own controller and there is also a controller in the plant room showing all the units. upon startup the outdoor unit fans start,the unit goes through its internal checks, the inverter compressors start to ramp up then shutdown. this cycle happens 3 times then the unit shuts down. when accessing the TEST button on the indoor controllers, the last fault code is E5 which is "overload of inverter compressor". i have checked the amperage of both compressors and (although each measurement slightly varies each time), the current at each phase can reach as high as 39 Amps. is this too high?? The compressors do not sound particularly noisy, i have "meggered" the compressors' windings and found readings of @ 350 megohms and 100megohms (to earth) respectively, so maybe the insulation is starting to break down. i had 10BAR standing pressure (410a) so i know theres a reasonable charge in there. any help would be greatly appreciated before i think about changing compressors or inverter boards......

[moondawn]

Hi there i thought that you could never tell how much refrigerant is inside a system be it small amount medium amount or large amount just going off standing charge, all standing charge can tell you is which refrigerant it is when comparing with a refrigerant compareter? Please can others confirm and the reason why as we all learning here.??

If you require service manual for this unit i have it and can email you. pm me your email address?



cheers lee

[mupdook1]

Hi Moondawn, thanks for the reply. you are right about the refrigerant charge. without actually recovering it i don't know exactly how much is in there. the problem i had is that the compressors shut down so quickly, the gauges hardly have time to measure a change from the standing pressure. however the fault code on the controller is not indicating a refrigerant problem, instead i am getting a "compressor overload" fault. i was hoping someone has had a similar experience and could advise me of which course of action to take.

[moondawn]

is the compressor shell really hot, maybe could try cooling the shell down if so to see if the system will run so that you could at least check pressures although i know with vrv/vrf pressures dont mean much.

it says in the manual that when the amps exceed 34 amps for 2 secs this error is produced.
the following are suspects for origin of failure:
�� Closed stop value
�� Obstacles at the discharge port
�� Improper power voltage
�� Faulty magnetic switch
�� Faulty compressor
�� Faulty current sensor

[mupdook1]

the administrator is not allowing my to send you a PM so thanks for the offer of the service manual, i wasn't being rude or ignoring you its just that i'm unable to send you my e-mail address. thanks anyway......!

[mupdook1]

the only heat in the compressors is the warmth from the crankcase heaters, and incoming voltage is normal. apart from that it was working fine up until Thursday so i'm sure nobody has touched any service valves. as to the others on the list, i will contact the Daikin techies on Monday to get more info. its just that i was going to shoot round there on Sunday if there was anything obvious i could do. i can take various readings but without knowing what i should be getting they dont mean much.

[moondawn]

there is a flow chart in this service manual which would be able to help you diagnose on the sunday i just need to email it you and your good to go mate

[mupdook1]

my e-mail address is in my vCard - that would be great, at least i can make a start on this before the workforce clock on at silly-o'clock on Monday morning. thanks for your help, its greatly appreciated.

[moondawn]

Email sent hope this helps please post back how you get on tomorrow.

thanks lee

[install monkey]

theres a setting u can put on the outdoor unit to disable the inverter compressor or the fixed compressor to give some limited operation.

[Tayters]

Hi there i thought that you could never tell how much refrigerant is inside a system be it small amount medium amount or large amount just going off standing charge, all standing charge can tell you is which refrigerant it is when comparing with a refrigerant compareter? Please can others confirm and the reason why as we all learning here.??

If you know the refrigerant type and system temperature and saturated temperature = system temperature then all that tells you is that there is enough refrigerant in the system for some of it to be in liquid form. How much or if it's enough you cant tell unless you weigh it out or run the system.

Cheers,
Andy.

[moondawn]

hi andy
so if a system has a molecule of liquid inside it will register the same standing pressure as would a system with a full charge of liquid refrigerant?

cheers lee

[Tayters]

hi andy
so if a system has a molecule of liquid inside it will register the same standing pressure as would a system with a full charge of liquid refrigerant?

cheers lee

Hi Lee,

That's correct.

[mupdook1]

just to update the thread, got back to site today and got on the blower to the techie's at Daikin. Now this particular model has 2 inverter compressors, each complete with independent control board and inverter board. if one compressor goes down it drags the whole unit down, so in order to carry out independent checks on each system it is necessary to "lockout" either the Master (right-hand) system or the Slave(left-hand) system. this is what i believe Install Monkey was referring to in his comment above. having been talked through the procedure to lockout the master compressor i found that the system still shut down on the same E5 failure code. with further instruction from the Daikin tech i disconnected the slave compressor, carried out another simple procedure which "proved" the integrity of the inverter board, thus i was able to diagnose a "partially locked" compressor. the unit is running temporarily on the master system and the new compressor is on order. thanks to Moondawn for the manual, it was very helpful. if anyone's interested i can post up the procedure for "locking out" the individual systems. thanks again...........

[tareg70]

Hi pal could you please send me the locking out procedure thanx in advance tariq, my e-mail is on my vCard

[a/c.king]

looking out inverter std1 std2 (std mean 3 phase com)
press BS1 on out door pcb unit for 5 sec
bress BS2 (SET) on the outdoor unit pcb 38times for inverter comp,39times for std1, 40times for std2
press BS3 (RETURN) on the outdoor pcb twise
press BS2 ones again to define.
in cace of multy outdoor units you carry out this steps on the master unit pcb. and u cant stop compressors on this case you only be able to stop master unit by pressing BS2 38 TIMES, or slave 1 by pressing it 39 times or slive unit 2 by presing BS2 40 time if any one need further informations about DAIKIN vrv Iam happy to reply.


acking

[brunstar]

i was going to say if the unit was drawing 39 amps per phase then you have a serious problem with the compressor seized, these compressors should not draw any more than about 8 -10 amps per phase so that is quite high!

[r.bartlett]

Originally Posted by moondawn
hi andy
so if a system has a molecule of liquid inside it will register the same standing pressure as would a system with a full charge of liquid refrigerant?

cheers lee

Hi Lee,

That's correct.

So when you're reclaiming why does the needle slowly drop to zero?

[Tayters]

Hi Richard,

The pressure would drop gradually because the reclaim machine is lowering the pressure in the system thereby drawing in the refrigerant which is now boiling off.

Cheers,
Andy.

[Mick13]

The pressure in the system will drop as you reclaim.... and its temperature will drop also. Ever noticed while your reclaiming after you have pulled alot of the refrigerant out the bottom of the suction accumulator will start to frost up?

But even if you reclaim half the gas (and say its pressure drops from 800kPa to 400kPa) and u pull the reclaim off and come back the next day, the standing pressure will be back up to 800kPa (presuming the ambient conditions are the same). It will absorb heat from its surroundings and increase in pressure again. As long as refrigerant is saturated (a mixture of liquid and vapour) it will maintain a pressure temperature relationship.

[spoon man]

Hello my reply may be to slow or wrong but here goes. You need to commision these units properly. they have a full start up and commisioning routine. Call daikin they can talk you through the procedure over the phone. It takes time. You are thinking larger problems before thinking simple - we all do it.

[spoon man]

Also standing pressure means nothng in any system unless it is completely open to atmosphere