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maki
17-07-2012, 10:07 PM
Hi.This is the first time i work on mitsubishi city multy and need help.I ve got two outdoors unit puhy-p300yhma and puhy-p350yhma joint together in puhy-p650yhma.I am the fourth or fifth person who came to service the system.

Customer told me that they are said it s problem with gas leakage and that are they every time add refrigerant in the system but they are not work so fine(coolinG) i recovered refrigerant and it was 50kg then i make a pressure test with nitrogen on 37 bar and there was no leakage.

Outdoors unit are on the roof of 7th floor and indoor are on ground floor and 1st floor hight difference 25meters.ON the first floor there are 10 indoors unit and on the second 14.

I put 40 kg by the book and there was no cold air on indoor.Then i put another 10 kg and i ve got cooling on ground floor but no on 1st floor.

And then customer told me that they have central controller g50 and there was 28indoor unit and they told me that problem start when serviceman before clean the units and after that one of them have water leakage. So I look at that unit and notice that every few second led flash goes on and off and one of the relay too and water pump didn't get voltage. Then i go to switch off the unit on remote par 21maa and nothing. And then they told me that there was a problem with that remote and they put new one and that are 3 indoors are on them but the old one stay and they have one more controller excess on the first floor.

That controllers have power but don't manage the units. Then i go to the first liquer store and getting drunk.

So my problem is did I put too many refrigerant and is there a problem with that few controller excess that I cant get cooling on the 1st floor. I used a manual for the add. refrigerant and I cant get the" Does 8°C [14.4°F] Tc-TH3 12°C [21.6°F] hold true?" its about 40°C booth and th4 is about 65-70°C th6 is also 40°C or I just need too add more refrigerant.

Sorry for my English and this problem who is my nightmare with that attentive customer.

The Viking
17-07-2012, 10:42 PM
Maki,

The only bomb proof way of finding the right charge is to get hold of the install manual for the outdoor units. Then measure the pipework as accurate as possible in a fully occupied building. After that it's just to enter the figures in to the table and the amount of charge will be given.


.

JoeAT50A
18-07-2012, 02:54 AM
Give us the sketch your system (model names or capacity code P50, P125 and so on) for indoor either with estimated piping lengths to us. I will estimate the additional refrigerant amount for you.
Alternatively you still can use the additional refrigerant adjustment flow-chart.
SW 4-3 ON
Test Run for 30mins
Then TH4 < 100C [if NO charge : If yes but too low : go to next step to see whether overcharged or not.]
Then 8C <=Tc-TH3<=12C [less than 8C then charge ; more than 12C recover]
Also you can judge with Tc-TH6 should be more than 20C and also watched the TH4 to maintain around 95C.
All fall between the range (so called adjusted) then SW4-3 OFF.
Refrigerant adjustment is completed.
Good luck.

maki
18-07-2012, 12:05 PM
On the first floor there are 13 units pffy-p25vkm-e
Ground floor 13 units plfy-p32vlmd-e
Main pipe to the first branch is the only thing i know because the installation project that they give me is not the real project.on that project is only 19 units.ground floor works fine but the problem is first floor outlet temp.from indoor is 21 C.Joe i do all thing that you said there is only 2C tc-th6 and tc-th3 also 2 C and th4 70C with 60kg of refrigerant.liquid pipe on indoor that work is 5C and gas pipe is 15.on the units on 1st floor liguid is 5 and gas is 21.Any idea.Thanks

JoeAT50A
20-07-2012, 07:50 AM
Are you using maintenance tool? then give me the data. TC is too low your High pressure is low I believed.
Could you please give me pressure readings and others if you do not have maintenance tool?

maki
23-07-2012, 08:22 AM
I dont have maintance tool all I can see is from sw1.HP is 25bar LP is 7 bar.I have one indoor unit wich can be turn on only by G50 but LEV is open only 41steps liquid 5 gas7C(problem with pcb reley and diode is every few second on then off).also there is one unit wich outdoor unit cant recognize her.Liquid pipe on all indoor is about 5C and gas pipe is 15-24C lev is from 141-322 only on one GUF100 lev is 532.My consider is did i put too many refrigerant or i can put it more to get good parameters or first i must fix problem with indoor units.Thanks

JoeAT50A
24-07-2012, 01:58 AM
25bar and 7bar are quite low >> in general (ambient 35C) judgement is around 28-30bar and 8to10bar.
But I have no idea solin - Croatia.
LEV index 41 is closed. If closed yet your liquid pipe temperature is 5 to 7C, then issue is LEV leakage and cold refrigerant make your outdoor not to run full speed and so called by passed process took place.
Check indoor TH2 and TH3 during stopping time. TH2 and TH3 too low there is a LEV leak.
Please check all these just in case. So that refrigerant adjustment can judge easier.

maki
26-07-2012, 05:48 PM
well i fix the problem with one unit wich outdoor unit cant recognize problem was in wiring with par21maa. I still have problem with another there is a problem in lev and i still cant get the right pressure and temperature, until i change lev(unit ON liquid pipe is 11C gas 7C unit OFF liq. 7C gas 0C) then check everything. how many kg of refrigerant is max allowed to charge the system?I doubt that I put maybe to much because I charge it but didnt know for problem with indoor unit customer told me for that problem after i charge 60kg:rolleyes: because the units are work when i turn it on with g50 and think everything is work fine, on first place i came to check is there a leakege in system.So i hope i didnt overcharge.Thanks :)

JoeAT50A
27-07-2012, 04:08 AM
The amount of refrigerant to be charged is calculated with the size of the on-site-installed liquid pipes and their length.
There is hard to say maximum allowable amount for additional refrigerant for the system.
We always used design tool to calculate. That's is the best.
However in case of gas leak (unknown amount) then we used sub-cooling and super-heat method Tc-TH3 and Tc-TH6 to adjust the refrigerants.
Overcharged system will be somewhat you can't able to get good parameters and performances. And if too much then don't worry you could have seen Error Code 1500 sooner.

maki
01-08-2012, 07:38 PM
Thanks for help i changed the lev on indoor and fiw wiring now everything work great.