Lg vrf

[slavex]

Hi All,
I have LG outdoor unit ARUN100LTE4 and one indoor unit- LG hydro kit ARNH10K2A2
all the time the compressor is working on 20-30Hz, that is not normal because set outlet water temp. is 50 deg.and actual temp. is 35. There is no problem with the compressor or some board, because after defrost cycle compressor is working on 140Hz and after 2-3min. again on 30Hz.
I tried with power reset, factory reset but no results, I checked all settings everything is by the book.Unit is working on system with fan coils and floor heating.

Any idea where should I look for the problem?

I didn't mention that unit is working without alarms.

[Tayters]

Are you saying your outdoor unit connected to the hydro box then the rest of the system is water based?

Mind you, however it's connected are you sure refrigerant charge is correct?

Sounds to me you are asking for 50*C but outdoor can only provide 35*C. Outdoor isn't speeding up because suction pressure sensor is limiting how fast the compressors run and the unit software isn't smart enough to deduce capacity is poor because of this or perhaps not enough refrigerant is lost yet?

Alternatively pressure sensors are reading incorrect and unit is basing compressor speed on this duff information.

Refrigerant charge is first place I'd be looking.

EDIT:
Is there enough water in the other side of the system. Suppose this would cause a similar scenario. Fridge pipes to and from hydro box would be hot in this case. If short of charge one hot (or warm) and the other cold.

Cheers,
Andy.

[AlexAlex]

Hi All,
I have LG outdoor unit ARUN100LTE4 and one indoor unit- LG hydro kit ARNH10K2A2
all the time the compressor is working on 20-30Hz, that is not normal because set outlet water temp. is 50 deg.and actual temp. is 35. There is no problem with the compressor or some board, because after defrost cycle compressor is working on 140Hz and after 2-3min. again on 30Hz.
I tried with power reset, factory reset but no results, I checked all settings everything is by the book.Unit is working on system with fan coils and floor heating.

Any idea where should I look for the problem?

I didn't mention that unit is working without alarms.

IMHO it is oil-returned operation.

Best regards,
Alex

[AC_From_Hell]

Tell me what are the refrigerant temps at the PHE. I bet that there isn't enough water flow trough the PHE and the system is running on low capacity, because of that.

[slavex]

hi to all,
i,m sorry for delayed feedback
in the meаntime i take out all refrigerant from the system(9.5kg. pipeline 8m)make a good vacuum and fill the system by the book 9.7kg. Nothing new, compressor is working again on low frequency.
Sometimes after power reset, system is working normally and i have 47 degrees(50 set.) on water outlet, but after 1 hour or 1 day again compressor is working on 20-30 Hz and the water temp is max 30 degrees.
because i have to big water pump i tried with bypass to decrease water flow trough the hidrokit but no results.
im going on site today and make new record of parameters, i will send you new data from the system.
thanks to all.

[The Viking]

Do you have the interface and software to look at what the system think it is doing? Or could you get assistance from LG themselves?

Quite often on modern VRF/VRV systems an incorrect reading from a sensor or a valve not opening / closing properly can have dramatical effects on the workings of the system but the system itself will still carry on running trying its best to compensate for the fault.
In these circumstances the only real way to see what is going on is to hook a laptop up and see what the system itself is reading from the sensors and what valves it think should be open.

[AC_From_Hell]

Send the record when you have it.

[slavex]

finally LG solved the problem, just with updating the software.

thanks to all