Any suggestion on cooling unit odd behaviour?

[mickado]

Good day to you all, I need some help on a breakdown, it's a rks50f Daikin unit, the error code is F3, on arrival the suction pressure was 14 bar in standby mode but when system was turned on pressure dropped down to two bar and the liquid line frosted over and so did the liquid line near the evaporator but the evaporator was blowing warm air, reclaimed the gas but the charge was correct? No leaks.
Any ideas as to what the cause could be? Thanks

[Brian_UK]

Blocked filter/strainer, expansion valve not working correctly.

Is the pipe length within the unit limits?

Also, how long did you run it for?

[Neddy]

What is the charge? Sounds like it could be something to do with the expansion valve if the charge is correct. Check the resistance of all the sensors. If they are ok replace the expansion valve head.

[The Viking]

OK,
First thing first...
When you say that the liquid line frosted over, which pipe did you actually look at?
Inside the outdoor unit or the pipes between out and in door units?

:cool:

[mickado]

Blocked filter/strainer, expansion valve not working correctly.

Is the pipe length within the unit limits?

Also, how long did you run it for?

Hi Brian,

The pipe lenght is approx 14meters long, reclaimed 1.6kg of refrigerant,

Client had system running when I arrived, isolated unit for five minutes or so then reenergised, check system was in cooling mode, i would say it took about a minute to frost after fan started.

[mickado]

OK,
First thing first...
When you say that the liquid line frosted over, which pipe did you actually look at?
Inside the outdoor unit or the pipes between out and in door units?

:cool:

Hi Viking

The pipes between condenser and evaporator

[Darrenp]

Any blockages , any kinks in pipe work at indoor unit

[install monkey]

http://www.mediafire.com/download/3kpfi0917ll9iz2/FTXS-G2V1B_SM.pdf
click on link above for manual- blocked drier/muffler- has a gauze before the lev or faulty/unplugged lev- no hi side gauge point
also check all sensor resistances are ok
could be sensor out of range or not connected on pipe

[The Viking]

Well, if you are looking at the pipework connecting the indoor unit to the outdoor unit I doubt you will find a liquid line. The EEVs in splits are normally in the outdoor units.
Therefore the smaller bored pipe of the two is also on the suction side of the system...
Hence, frost if it is unlagged would be normal.
Other than that, as Mr Monkey says above.

:cool:

[Neddy]

The smaller pipe is the expansion line. Frost on this pipe is not normal as this indicates the Refrigerant is evaporating below 0k .You don't have the correct flow of refrigerant leaving the Condensor.