E4 fault on RXYQ12P7

Hi everyone, how are you...
Got a problem on a VRV RXYQ8P7W1B (unused), i've made the commissioning 7 days ago. The system failed to E4 the first night after ( low pressure detection by pressure sensor).
I recovered the refrigerant and found the good amount ( total=9.53kg ).
In the meantime i tested the pressure sensor reliability compared to my low pressure gauge manifold and the service checker data. I made a complete vaccum during 3 hours and started again to check it in heating mode.
After the system reached the HP target (50°C), i found the discharge pressure slightly high : 112 to 115 °C with discharge step down control activation, there were ice just after the main EXV output to the heat exchanger (just at the beginning).
The system failed to E4 again the last night !!! don't know exactly why i'm getting bored by an unused system !
Maybe a matter of bad EXV or something like that, i got a data recording of the 2nd commissioning.
Need your kind advises please it's for a child care centre..
cool#9

You are sure about the additional charge?

Total pipe length about 10-15 meters?

(9.53-8.6 = ~1kg = ~8m 1/2" pipe)

Quote:

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Originally Posted by The Viking

You are sure about the additional charge?

Total pipe length about 10-15 meters?

(9.53-8.6 = ~1kg = ~8m 1/2" pipe)

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Hi Viking
The original charge on the nameplate is 7.7 kg.
The 1/4 length is 43m x 0.022 so 0.946 kg
The 3/8 length is 15m x 0.059 so 0.885 kg
Additional refrigerant is *******1.831 kg*****
Total amount is*************9.530 kg*****

Your remark is true we have to check the length once again maybe there's a mistake, we'll dig it on next monday morning..
Thanx
cool#9

Ok,
Just a thought...
But in the manual I downloaded it said 8.6kg and 1/2" to the first T.
Hmm, can't believe that a Japanese manual would be wong.

Quote:

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Originally Posted by The Viking

Ok,
Just a thought...
But in the manual I downloaded it said 8.6kg and 1/2" to the first T.
Hmm, can't believe that a Japanese manual would be wong.

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Hi The Viking
I made a mistake.. it's RXYQ8P7W1B !!!
Sorry i'm editing my post.
cool#9

Cool#9

Can you check the actual cables coming out of the low pressure sensor? They may be broken. If that is the case you will need to replace the pressure sensor. To do this you will need to remove the entire refrigerant as the sensor is a brazed type. Don’t forget to wet-rag the sensor when brazing.

Let us know what you find.

Obi Wan.

Thanks Obi Wan
It's true the cables from the low pressure sensor were tighten high...
We had a lot of problems with HP sensors and JA fault on other VRVs, P series.
In this case we had no JC fault but your opinion is good, we maybe have the same problem due to wrong reading.
If the additional charge is correct upon the field length we will change both LP sensor and main EXV.
rgds
cool#9

I have also had the same type of problem. The low pressure sensor was changed and we have had no problems with the system.

HI MATE ,THIS IS VIJAY i m a/c tech ,i just joined this site ,i read the problem which u r facing ,my suggesion is just double check the length of pipe and check weather any additional charge required cos these units r very precisely charged and my it could be pressure swich fault ,i dont think its expension valve
cheers

Quote:

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Originally Posted by vijaypal15

HI MATE ,THIS IS VIJAY i m a/c tech ,i just joined this site ,i read the problem which u r facing ,my suggesion is just double check the length of pipe and check weather any additional charge required cos these units r very precisely charged and my it could be pressure swich fault ,i dont think its expension valve
cheers

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Thanks vijaypal15 and welcome on RE forum.
I'd like to thanks everyone also cause i'll begin the week with good advises.
I will tell you how i'm getting on.
rgds
cool#9

Hi mate:
as you know that E-4 is a malfunctiong code for low pressure in suction side. try the followings:

1. pressure switch- if the refrigerant pressure side becomes abnormally low.the pressuer switch stop the operation of the unit automatically.
2. pressure control valve- It controls the cooling operation. the low pressure valve sense the low pressure which is about 4kgf/cm-g or less (the pressure of the fan coil unit) and bypass the discharge gas from the compressor to the accumulator.

Hello All,

Reading some of the posts, some of you are correctly relating to the E4 error to a Low pressure switch. In case of the split or Sky Air systems this is correct. However on the VRV systems there is no low pressure switch but there is a low pressure sensor. If you get an E4 on the VRV system then it can mean that the low pressure is very low (less then 0.07MPa). This can be due to refrigerant shortage, Faulty low pressure sensor, Or a faulty main outdoor PCB. The hot gas bypass valve should also be checked. (I once had the ¼” pipe totally blocked with over brazing on the hot gas bypass valve)

The above would be the case during normal operation.

You can also get the E4 error code during the mandatory test operation on the VRV II & III systems. In this case it can mean something different. I attach a list of error codes and there descriptions during the test operation.

Obi Wan.

Hi, how are you...?
Ok, i went back seriously on this problem on found the length were wrong...
After new calculation i put 1.88 kg of R410A and the system didn' t fail last night, the Child Centre opened this morning :D , for this VRV a new life has began !!!

We should always go back to basics that's a fact...

Now i try to find a service manual for VRV III HR, i don' t want to start a new thread about it, i think an hope someone will link me to this document...

rgds

cool#9

Cool,

Your wish is my command.

Have a look at my website HERE and you will find what you wish for.

(NO, not that long legged blond bird with a great pair you dream of but almost as good, ie the Daikin manual)

PS. If you can't find it then look below the fault code downloads.

Quote:

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Originally Posted by The Viking

Cool,

Your wish is my command.

Have a look at my website HERE and you will find what you wish for.

(NO, not that long legged blond bird with a great pair you dream of but almost as good, ie the Daikin manual)

PS. If you can't find it then look below the fault code downloads.

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Thanks The Viking but i need the same for Heat Recovery series.!
The reason why is that in France it's quite difficult to get information.
15 years ago i met a japanese technical manager who said to me " ***** everything you need to know about Daikin 's product is written in the SERVICE MANUAL...just take time to read it"
Since i try to make my own collection of data and learn on the field.
rgds
cool#9

Sorry, my mistake
(I just gave you the one for the model no you posted!)

I will have another look and see if I got it lying around somewhere


EDIT:
Sorry but according to Daikin's website it hasn't been launched yet, so we probably have to wait a while for the manuals

Quote:

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Originally Posted by The Viking

Sorry, my mistake
(I just gave you the one for the model no you posted!)

I will have another look and see if I got it lying around somewhere


EDIT:
Sorry but according to Daikin's website it hasn't been launched yet, so we probably have to wait a while for the manuals

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Thanks again but i've found it after 1 hour on google... it's called Si 37-701 an now i can go ahead.
rgds
cool#9

Link to it?

Quote:

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Originally Posted by The Viking

Link to it?

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See my PM please
cool#9

http://207.45.127.154/daikin/Default.aspx?tabid=142
Posted this link it already in another section