Points to check the Indoor unit functioning properly

[sachin230]

Daikin VRV III, IDU -FXFQ,ODU -RXYQ

Can anyone guide me,

Which point we have to check to know the indoor unit functioning properly if model selection correct or wrong.

What should be the difference range betn suction & discharge temp of indoor unit.

What is the method to measure & rectify the heat loss.

How we know if there is any gas leak (through indoor unit accessories.R410A is odourless)

Thanks in advance

[Mentallist]

Hi,
There is a simple way to check the operation of VRV systems.
Coolin:
Set the system to operate with all indoor units set to 16 degrees. The diffrence between you air on and air off temperatures should be >10 degrees.
Heating:
Do the same test, but in heating with a set point of 32 degrees. A differential of 15 degrees or more should be noted.
If these temperature differentials are lower than that described above, then activate an automatic charge operation. This can be found in the service/installation manual and during the function will either tell you by codes such as "PA" that additional charge is required.
The differentials decribed above may be slightly less if the system is indexed over 100%. This is common these days when consultants design systems. Dont be alarmed, the system will operate satisfactory under these conditions.

[sachin230]

Is this only one way ( difference betn suction & discharge temp of indoor unit) to check the proper functioning of indoor unit ?

[sachin230]

Hi,
There is a simple way to check the operation of VRV systems.
Coolin:
Set the system to operate with all indoor units set to 16 degrees. The diffrence between you air on and air off temperatures should be >10 degrees.
This can be found in the service/installation manual and during the function will either tell you by codes such as "PA" that additional charge is required.
The differentials decribed above may be slightly less if the system is indexed over 100%. This is common these days when consultants design systems. Dont be alarmed, the system will operate satisfactory under these conditions.


I am facing problem,room does not cool /set temp not achieved.

your reply & attached flow chart for troubleshooting. I am confused

[Mentallist]

Sachin,

Can you provide further details. Is it 1 indoor unit that you have the issue with or all units. What is the model type, does it have a remote controller fitted, where are you sensing room temperature from - Body sensor/wall sensor/remote controller sensor.

[Brian_UK]

I am facing problem,room does not cool /set temp not achieved.First thing, is the unit correctly sized for the load in the room?

[sachin230]

Daikin VRV III
It is first indoor unit which I facing problem out of thirteen indoor unit in one system. Cassette is ceiling mounted Model -FXFQ100PVE, outdoor Model -RXYQ18PY16, RXRQ10PY16 Total 28HP system for 13 indoor unit.
In one common area 4 nos FXFQ100PVE models are fitted, out of four one unit has a cooling problem. Operational settings are identical for them. Remote controller is (standard) wired remote controller.

For troubleshooting,
1) Bypass the remote thermostat & activate the body thermister.No error code found in field parameter 40.No any malfunction code found on remote controller
2) Check evaporator coil found cleaned .unit is installed & commissioned before 1.5 year.
3) check Grill in & out temp difference between them is 9 to 12 degree.
4) To remove the PCB card malfunctioning doubt, replaced the pcb card


So I put question in thread

Which point we have to check to know the indoor unit functioning properly if model selection correct or wrong.

What should be the difference range betn suction & discharge temp of indoor unit.

According to dealer the unit correctly sized for the load in the room but I want to verify the total system

Can you guide me
1) About the mention question in thread
2) where can I get information about the design of system in India (How to select Indoor & outdoor model, capacity all information related to design)
3) How to identify /monitor the system is fully functioning properly without using I touch controller/service checker type III.

I am excepting answers or you can give me a source of information from your great experiences.

Thanks in Advance

[Sridhar1312]

Normally where you have multiple indoor units it is necessary to provide refrigerant leak detector so that you know there is refrigerant leak and take preventive action.
Otherwise you will lose refrigerant and also create Oxygen depletion if the leakage is more than allowed which can lead to oxygen depletion.
Normally the same vendors provide leak detectors near every indoor units n many of the countries where the standard calls for such requirement. In India the vendors do not even talk about this.

[sachin230]

Thanks Mr Shridhar
can you tell me the approximate cost of refrigerant leak detector. we have 56 ceiling mounted indoor units

[Mentallist]

Sachin,

As per my previous posts, please see below:

Test 1:
Operate system in full cooling, all indoor units 16 degree set point and allow operation to start. Wait for stable conditions and take Air On and Air Off temperatures of each indoor unit. The VRV system should be able to ensure a differential of > 10 degrees between the air on and air off of each indoor unit.

If this indoor unit is not producing such capacity, then the following should be checked.

Indoor Expansion Valve Coil Resistance
Possibility of partial blockage within the field piping
Possible partial blockage of liquid line filter
Failure of indoor unit expansion valve body
Is the refnet of the field piping supplying the indoor unit installed correctly - Should be horizontal + or - 30 degrees

Further investigation of the unit is required to make final diagnostics