daikin vrv's

[Latte]

Hi Frank,

Got a problem with a VRV that keeps going out on E4 (LP Switch).

Other engineers have check the switch and it isnt going out. After suggestions from Daikin the compressor and the discharge line sensor have been replaced. Is there anything else on the system that could cause an E4 fault

Regards

Fatboy

[Argus]

Hi Frank,


After suggestions from Daikin the compressor and the discharge line sensor have been replaced.




How can a system with a dead pot trip an LP switch?

.
________
Lincoln Continental Mark IV (http://www.ford-wiki.com/wiki/Lincoln_Continental_Mark_IV)

[Latte]

Hi Guys,

I wrote the original post while i was in the office before going out to the job just in case someone had come across this before.

Today, was the first time i had been to this site for this problem, apparently this problem has been going on for months with sucessive engineers failing to find the fault.

The VRV is a RSXY5GY1 and it runs 7 indoor ceiling systems on 4 controllers (One controller does 4 units the other 3 have seperate controllers). All the controllers show E4 fault. In the past engineers have fitted equipment onto the LP switch to see if thats playing up but no good. I think the pot was changed in case that was throwing a wobbly.

Now today, i have reset all the controllers and run them on test mode and all OK. Check gas 10bar discharge and 4.4bar back pressure (Seems high for R22) fans indoor and outdoor all ok and suction frosting back to pot. All units set to 23 degree C on cool mode. Checked LP switch wiring and all OK.

The problem in the past i am told is the unit works fine for a couple of weeks and then throws his code up for no apparent reason :confused:

Any Ideas anyone

Regards

Fatboy

[slingblade]

I may be wrong!!! but best guess is that if all 7 units are running and you have 10 bar hp then system is short of refrigerant. 10 bar 150psi approx. is low for r22. 4.4 bar 65 psi approx seems ok. when the temp decreases and units begin to shut down on thermostat {4 on one control and 3 single} the suction will drop {possible lp fault}. as far as my knowledge of daikin goes the inverter will slow down and after that a hot gas unloader will open {rsx10h} have you tried running just one ahu to see what happens. i have {more than once} come accross a daikin unit where the "self diagnostic" fault code bears no relation whatsoever the system fault. good hunting.

[Latte]

Hi Guys,

Thanks for the replies, The only thing that concerns me is that the VRV is already frosting back to the compressor. Surely if i put more gas in then this is going to get worse ?

Regards

Fatboy

[martind]

I have to say, that I do not have many experiences with G-series, this is quite vintage model, but...
First of all, the LP switch should be tripped under 2bar.
If you were there and it tripped over this pressure, the switch is wrong. But it won´t be your case I guess because of frozen suction pipe.
Second thing you should check is the low pressure sensor. Unfortunately, I do not know what pressure sensor is really there. Check the supply voltage 5VDC between black and red. The output voltage (If there are 4 wires - between black-green or white, one is not connected, if there are three wires between black and white):
Low pressure = (Outp. volt - 0,5)*10/3
Check with gauge manifold.
Then, if this is OK, check the subcooling at test mode, if there is no subcooling, there could be refrigerant shortage, but if there is some subcool, refrigerant shortage is not your problem.

[Dns]

Yes, agree with martind. If the above is OK. the you have to replace the outdoor PC card.

[slingblade]

Firstly i am assuming all 7 units are calling for cooling so th cond. unit is fully loaded, are the coils and filters clean. heavy suction frosting sounds like poor evaporation in any situation but you state that all machines are set for 23c so this {in theory} should not happen. the only true way to determine your charge is to recover and weigh back in. i know this sound like a real ballache {and unnecessary if you know what your doing in the first place} but i did this on an rsx10 and found 6kg short much to my disbelief. system charge must be added to calculated extra for pipework and ahu's. this will eliminate any doubt over gas related problem. all the info on this should be in the original daikin installation book if they have it. i still wouldn't rule out circuit boards. in short "it could be ****ing anything!".

[Cofreth]

Code E4 blinks for 'G' series either low pressure switch set value out of calibration.
Low pressure switch activates due to shortage of refrigerant or clogged piping.
Defective Outdoor PCB. or pressure sensor defective.
With a high pressure of 150psig for R-22 will be consider under charge.What is your ambient outdoor air temperature?
But with a suction pressure of 65 psig definitely you can't get any frost on the suction line, 65 psig for R-22 is above freezing point of water.
I think there are more to check on the system, either you may have an erratic pressure gauge.

[Latte]

Hi Guys,

Ambient about 18 degree C, Pressures via Manifold gauges as no gauges on unit so should be correct to within a couple of PSI.
Diffinatly frosting back to the compressor.

Looks like someone needs to spend some time there and climb into the roof and check over the indoor units.

As usual didn't have too much time on site, Oh the life of a Refrigeration Engineer is such a busy one :D

Regards

Fatboy

[martind]

That is the best work. No time, customer standing behind you, and mysterious problem. Tomorrow I have to go for something like this. I really like my job sometimes :c
Just make checks of the LP switch and sensor. The compressor frequency is controlled according to LP = 5-6 dg. C. If the low pressure is wrong measured, then the frequency could be higher >> system goes to low pressure.
If the LP sensor is OK, you have to check temperatures after all indoor units, as you already mentioned and the liquid temperature.
Good luck

[Cofreth]

Hi Guys,

Ambient about 18 degree C, Pressures via Manifold gauges as no gauges on unit so should be correct to within a couple of PSI.
Diffinatly frosting back to the compressor.

Looks like someone needs to spend some time there and climb into the roof and check over the indoor units.

As usual didn't have too much time on site, Oh the life of a Refrigeration Engineer is such a busy one :D

Regards

Fatboy

What kind of indoor air temperature do you have?
18 degrees outdoor will never turn 'ON' the compressor with a thermostat setting of 23 degree.
Unless you have a very high heat load found in the air-con room.

[frank]

Hi Raymond

Sorry for the delay in responding but today is the first day back after a well earned break in the SUNSHINE :D

Over the years, I have learned that whatever the Daikin fault code says is 99.9% true. Computer logic only has one path.

If you are getting an E4 fault then you have a low pressure system malfunction.
This could be caused by a number of things,
Failure of low pressure switch
lps wiring is broken or faulty
failure of lps connection to pcb
loss of refrigerant charge
failure of outdoor pcb
cause related to system as a whole (their words not mine :D )
malfunction of refrigerant piping circuit

Now, without a crystal ball or site visit (chargeable at reasonable rates :D ) I would have to look at the symptoms step by step:
1) system runs and fault occurs randomly so no loss of refrigerant
2) system runs for 2 weeks (as per previous post) so it is an intermittant fault - could be faulty wiring, pcb fault, lps fault etc.
to check the switch and wiring it would be safe to link out the connection to the pcb for a couple of weeks as it seems the gas charge is OK.
If the system runs Ok with the switch bypassed then it would not indicate a fault with the pcb or refrigerant circuit

And you mention that the system frosts back to the compressor. I would look toward the circuit piping (is it within maximum distances?, any kinks in the pipework?, does the compressor ramp up and down excessivly?, are the indoor units within the index allowed? etc.
It is very difficult to pinpoint the fault from a distance but you must use logic.
Can you post a list of the indoor model numbers? with this I can determine the index rating

I have a piece of kit that connects to the pcb and tells me what every part of the machine is doing at any particular time on the laptop - very useful in these situations

[Latte]

Hi Frank,

I will pass that on to my boss (Cooling-gurus) and let him sort out what our next step is.

I will send you a PM as i need to ask about things but not on the forum

Regards

Fatboy

[Latte]

Hi Frank,

Just good the unit details from the file in the office

According to our records the outdoor is a RSXY5GY1 and it feeds 4 x FXYS25G's 2 x FXY40G's and one FXY32G. all the indoors are on the ground floor. I dont think the pipe run is excessive it certainly shorter than some i have seen. What is the maximum pipe run on these units.

Another question slightly related. When a unit comes precharged for a 15 meter pipe run i assume this is in total (suction and discharge meaning indoor and outdoor unit must be no more than 7.5 meters apart) is this correct or is it 15m on each suction and discharge

Regards

Fatboy

[frank]

Hi Raymond
I'll look up the Daikin details tommorrow at the office and post back. The maximum indoor outdoor distance for a G series VRV is 100m (loosely the same for most makes in the early days - pre R407c/R410A) with the first indoor unit to last indoor unit being 40m. So you could go 60m of pipe from the outdoor unit, then make your first indoor unit and then feed all the other units making sure that the they all fall within the 100m limit.

It increased to 125m for R407C, with the first indoor unit a maximum 75m from outdoor.

When the manufacturers state a maximum pipework distance it refers to a one way measurement so if it's charged for 15m sepeation then it can be 15m - not divided by liquid and suction lengths.

[martind]

to MrCoolingMagic:
This is good example :) E0
From my experiences E0 is common malfunction, if the indoor unit needs cooling and the outdoor does not cool from any reason, which could not be detected by any other protection.
E0 is descripted as an activation of protection device (fan thermal protection and overcurrent relay), but...
Some of E0 cases:
Instanteneous power failure - in many many cases
Inverter problem - totally burnt or some disconnection
Reversed phases (in case of older small Split units)
Outdoor PCB cold junction on some connector
Mechanically blocked compressor
etc...

[Temprite]

:D llllllllllllllllllllllllllllllllllooooooooooooooooooooooolllllllllllllllllllllllllllllll
lmfao daikin really are ****e. s.h.i.t.e

Sounds like you've got a bit of an axe to grind with Daikin.

Care to elaborate.

[martind]

Man, this is the thread (http://www.refrigeration-engineer.com/forums/showthread.php?t=3072&highlight=daikin)for your effusions.

[Latte]

LOL how much did that red herring cost?

Whatever the cost it is worth it to keep our customers happy :rolleyes: .

This is one of those jobs that you have to be in the right place at the right time. If anyone can sort these out it's normally Frank. Bladesling, i am surprised you have had many problems wih Daikin. Mostly they are more reliable than some other makes i could mention.

Regards

Fatboy

[rbartlett]

Whatever the cost it is worth it to keep our customers happy :rolleyes: .

This is one of those jobs that you have to be in the right place at the right time. If anyone can sort these out it's normally Frank. Bladesling, i am surprised you have had many problems wih Daikin. Mostly they are more reliable than some other makes i could mention.

Regards

Fatboy

he's a salesman who judging by some of his posts is suffering from quite a major inferiority complex both personally and the kit he has to sell....

still the way he's going about it he won't be here long .

cheers

richard

[fridge51]

I have been following this thread with some interest
i like most have had dealings with daikin direct and through their agents some of which no longer exist
i have had warranty issues on replacement compressors which have been faulty at start up,when original compressor has run for years {different faults i might add) where daikin will not replace unles a serial no is given, and when you tell them it is nolonger readable they just shhoo you. i have experience of an agency selling warm climate heat pumps to a user in the uk (45 splits in total}so that in winter they do not operate in heating etc etc

i believe daikin are called daikin as ford already had the name anglia

my apologies to frank as throughout all my grief he has been of great help in sorting out all the c**p that generally ensues when you are called to a daikin installation

[rbartlett]

I have been following this thread with some interest
i like most have had dealings with daikin direct and through their agents some of which no longer exist
i have had warranty issues on replacement compressors which have been faulty at start up,when original compressor has run for years {different faults i might add) where daikin will not replace unles a serial no is given, and when you tell them it is nolonger readable they just shhoo you. i have experience of an agency selling warm climate heat pumps to a user in the uk (45 splits in total}so that in winter they do not operate in heating etc etc

i believe daikin are called daikin as ford already had the name anglia

my apologies to frank as throughout all my grief he has been of great help in sorting out all the c**p that generally ensues when you are called to a daikin installation

As mentioned our Daikin warranty % is currently at naught. I agree we are not immune from technical problems but if you employ competent good quality guy's and work to a decent standard then Daikin will seldom if ever give problems.


Pretty much all the manufacturers know that most warranty calls are usually install related and if you are always having troubles on daikin sites then I suspect someone is giving away a lot more information about themselves that you'd prefer customers not to know..

A friend who was a warrenty tech for Mitsi (now operations manager for LG) would always always check to wiring first on any call he went on and usually this was the 'problem' not the kit

A lot of monkeys have got into this game over the last 5 years and it shows..

cheers

richard

[rbartlett]

still the way he's going about it he won't be here long .



Agreed. the INTERNET fridge police are most likely on the way as i type.


This is the best forum for discussing refrigeration /air conditioning I know and it's kept that way be stopping ijits and trolls from abusing it.

Alt.hvac was the best but look at it now..competely ruined by bad language and trolls spoiling it.

Look at fridgeman-something tells me you know this site... ruined by the mod allowing all sorts of stuff to go on so the serious guy's with information leave (and usually come here saying "what a breath of fresh air it is")

The only way for this site to continue it's good work is to stop this stuff.Others have been banned here for less than what you've posted thus far so don't feel persecuted BTW

Have a think about it and either join in and give us the benefit of your experience or go to either of the above mentioned and post there..



cheers

Richard

[frank]

As mentioned our Daikin warranty % is currently at naught. I agree we are not immune from technical problems but if you employ competent good quality guy's and work to a decent standard then Daikin will seldom if ever give problems.

Well said Richard. That's my general feeling, but, I also have had issues with Daikin, although, through SpaceAir, I've never had any real issues that haven't been sorted.

One such problem was No.6 compressor failing on a VRV install. (26hp outdoor with 9 indoors rated at 52kw cooling.) Seems that the crankcase heater was incorrectly sized during design stage so that, when the last compressor was called, it just pumped all the oil out.
Didn't take long for the comp to fail, bearing in mind that the last compressor spent most of it's time waiting for the indoor conditions to approach maximum load.
We got paid all our costs including gas, time, expenses etc. - can't say fairer than that.

[frank]

Where has the fault code E0 been mentioned in this post? :confused:

[fridge51]

Pretty much all the manufacturers know that most warranty calls are usually install related and if you are always having troubles on daikin sites then I suspect someone is giving away a lot more information about themselves that you'd prefer customers not to know..


i must point out that our company does not have trouble on all daikn jobs. but i find that if we attend a customer that already has an installation,that requires a service call 9 time sout of ten its a pain!

every body must have had the 10/12 week lead time on certain spares, and before daikin uk got together suffered at the hands of cvarious agents ( you know who you are)
as with every aspect of our industry as you rightly say, monkeys move in,unfortunately there are a lot of zoo keepers out there too

regards to all

phil thompson
service director
F T Refrigeration Ltd
www.ftrefrigerationltd.co.uk

[martind]

You are completely right gentlemen. Look at this thread. We were solving specific problem and one "reply" shifted this discussion to completely another direction.
We cannot do anything, only ignore such replies.
Banning users had to be done by site admin and I do not think, that he has so much time. Just be lucky, that this site exists, order must be maintained by ourselves.
Just to turn this thread to original position:
What is going on rdocwra? Do you have any info from your boss "guru"

[Latte]

OK GUYS,

Back to the original Thread,

I managed to get back to the site today and get some more info. Apparently this fault only occures when the unit is on heat mode :eek: .

I have never seen a system controlled like this, although there are 4 seperate controllers in 4 different rooms in one of the rooms is a daikin panel with 2 toggle switches on it. The top one is fans to the left and temp to the right. The bottom switch, cooling left and heating right. By using this switch you lockout all the controllers into either heat or cooling mode (Does this make sense)

Anyway thats as far as i got today. Fault in Heat mode
Any Ideas Now

As for Cooling-guru he get his information the same place i do (Frank)

Regards

Fatboy

[martind]

The control with central cool-heat changeover is normal.
If the error is happened in heating mode you have simpler situation as you have to check temperatures only on outdoor unit.
If I should say anything without detailed informations, in heating mode could also be the reason of low pressure the electronic expansion valve in outdoor unit. But you have to be sure, that E4 is during heating and not during defrost.
If the error is happened only sometimes the best way to analyse this is the parameters logger. I know, that this is quite proprietary tool, but maybe you know somebody from DAIKIN who has this (the name is Daikin Service Checker). We in Slovakia are lending this to dealers if such problem occurs.

[cooling-gurus]

With regard to more information for Ray, i can only give you more background on the fault, as i have had previousl engineers go to this site and carry out works as per Diakin Technical. The original complaint is the same, fault E4 occours intermittantly. Going back to the begining it all seems to start from a leak on caplillary line, which was repaired and recharged accordingly. Several calls to state the system was not working, on arrival the cutomer had reset the system and got it back working, making it difficult for us to pin point the fault. It then went out on code F3 after several checks Daikin suggested a fault with the internal valves of the compressor and the discharge pipe sensor. Unfortunately i was not convinced and went for the cheaper option of the discharge sensor. We then managed to find out that the receptionist was arriving in the morning and feeling cold tunred it on full heating then once warm tuned it down to Cooling to the original setting, this was an ongoing problem until she was told not to touch the controllers.

Again the fault re-occoured so we opted for the compressor replacment as per daikins advice. They then suggested a Tattle Tail to be installed on the Lp switch which we did and left for some time, this did not give us any further information except it didnt blow.

As suggested previously i think (bearing in mind i am not a A/c engineer) but as frank suggests LOGIC it must be either a PCB or Lp switch fault.

This is based on Discussions with Ray, but what do i know------------Not alot i can tell you

Obvioulsy changing the compressor and discharge pipe sensor on Daikins recommendations has proved that it wasn't that.

Thanks for all the advise being given i am very appreciataive of all the help.

Cheers

Cooling-Guru

[rbartlett]

if the fault seems to coincide with the capillary I would look at
a charge
b moisture

then go from there..

cheers

Richard

[frank]

Hi Raymond

I've managed to look at the manual for the kit and can report the following findings

Outdoor unit = RSXY5GY1 (Index capacity = 162.5)

Indoor units = 4 x FXYS25G (index = 4 x 25 = 100)
2 x FXY40G (index = 2 x 40 = 80)
1 x FXY32 ( index = 31.25)

Total indoor index = 211.25

Raymond, the system is mis-matched :eek: The correct outdoor unit should be a RSXY8

[Latte]

Thanks Guys,

I take on Richards point about moisture, i know the system has had a gas leak in the past and the problems only started after it been repaired but need to check if its had a drier.

Another thing, if this unit is going out on LP in Heat mode and the sytems is switchable so it can only run units in either heat only or cooling only (Not both at the same time) does this unit act the same as a split and reverse the cycle (Discharge becomes suction and vice Versa). If so if it goes out on LP is there another LP switch on the Discharge side (Suction on heat) or does the board somehow work out what mode it's in and run the LP anoher way.

The plan is to sit down with cooling-gurus and go through the file from scratch. Maybe the first step should be reclaim all the gas, weigh it, change drier(s) and recharge. The trouble is a system of this size is going to need a long vac out (Overnight possibly - any comments)

I knew i should of gone sick the day i first got this call :D

Regards

Fatboy

[rbartlett]

on any heatpump the suction going into the compressor is always the suction whatever mode it's running on.

therefore if you fit the lp by the compressor it will always measure low pressure

cheers

richard

[rbartlett]

Hi Raymond

I've managed to look at the manual for the kit and can report the following findings

Outdoor unit = RSXY5GY1 (Index capacity = 162.5)

Indoor units = 4 x FXYS25G (index = 4 x 25 = 100)
2 x FXY40G (index = 2 x 40 = 80)
1 x FXY32 ( index = 31.25)

Total indoor index = 211.25

Raymond, the system is mis-matched :eek: The correct outdoor unit should be a RSXY8

frank what is the index of the 8 ?

cheers

richard

[frank]

does this unit act the same as a split and reverse the cycle
Raymond
The answer is yes. VRV units come in three types:
Cooling only
Heat Pump
Heat Recovery

The first 2 operate exactly as a split system would (or more accurately, a multi split) the third system is what defines the VRV system. Waste heat from one room can be used in another room or rejected to atmosphere.

A system is in balance when the heat absorbed is rejected together with the heat of compression. A VRV heat recovery system can maintain this balance under varying conditions, from fully cooling, across partialy cooling and simultanious heating to fully heating.

One thing that must be true though is that the system operates within the boundaries set by the manufacturer. If you try to operate a VRV system outside of the published data you will get unexpected results.

The intermittant LP fault you are experiencing is due to your system being out of balance. When the unit is operating in heating mode, all the indoor units are acting as condensers and send the liquid back to the outdoor coil which acts as the evaporator. As your system is not index balanced, the outdoor unit would be starved of liquid and would show low pressures.

In cooling mode, the result would be low capacity on all indoor units.

[frank]

change drier(s)
There is NO drier to change on a VRV

The trouble is a system of this size is going to need a long vac out (Overnight possibly - any comments)

The recommended time for a proper vacuum of a system is 8 hours and a triple break with OFN

[frank]

Richard

The maximum index for a RSXY8 is 260, the minimum being 100

[chemi-cool]

There is NO drier to change on a VRV

You will be surprised Frank what you can find.:D

I will show you some beauties around Christmas time.

Chemi:)

[Latte]

Hi Frank,

My guess would be that the unit would not have had an 8 hour vac or a tripple break, a couple of questions though.

1) when would you break the vac, time,micron," of vac or just whenever.
2) Although no drier fitted originally, would you gain anything fitting a bi-directional
3) Even if i had a micron gauge (which i dont, not at £130 anyway) where could you fit it. Assuming you should fit it at the furthest point from the vac pump and you vac at the outdoor service ports where could you fit it. Are there any 1/4 service ports on the indoor units, ive never seen one


Regards

Fatboy

[rbartlett]

Richard

The maximum index for a RSXY8 is 260, the minimum being 100

so what is max/min for the 5 then?

cheers

richard

[frank]

so what is max/min for the 5 then?

cheers

richard

RSXY5 Max 162.5 Min 62.5
RSXY8 Max 260 Min 100
RSXY10 Max 325 Min 125

[Latte]

Frank/Richard,

Right, Here is my thinking :confused:

FACT:- We know the system was OK Before it had a gas leak so logic dictates tis is the first place to look

First, go to NRS and get a Midi reclaim bottle (we think system has about 15kg R22)
Reclaim gas and weigh, Fit Bi-directional, Tripple-vac Overnight, Regas and try.

Anyone have objections or suggestions.

I think i have got to start with the basics and go from there at least this way it eliminates gas. How do you charge a vrv if you dont know the pipe lenths. although this one should be within spec if the unit is underpowered or you dont know the lenghts what do you do. Pressures, Frosting back ?

Regards

Ray

[frank]

How do you charge a vrv if you dont know the pipe lenths.

To correctly charge a VRV/VRF you have to measure the total liquid line length and sizes. You then apply these lengths to a formula provided by the manufacturer. Do the sums and then charge the total amount.

The problem here Raymond is that your system will not work correctly as there are too many indoor units connected to it. You have an imbalanced system.

For Daikin (RSXY5) on R22 the formula is
1/2" liquid line length (m) x 0.1 = ?
3/8" liquid line length (m) x 0.05 = ?
1/4" liquid line length (m) x 0.025 = ?

Add all the answers up and subtract 2. Add this result to the name plate charge and the system will be correctly charged.

:( However, in your case, as you have too many indoor units connected, the answer will result in an over charge.

[frank]

Reclaim gas and weigh, Fit Bi-directional, Tripple-vac Overnight, Regas and try.


No objections here Fatboy but leave out the Bi-directional. No additional filter/driers are required.

[rbratlett]

No additional filter/driers are required.


i agree with frank, if it's not required then it's not required.

[Thermophysics]

i agree with frank, if it's not required then it's not required.

You're not really agreeing with Frank, are you. You're simply stating that something not required is therefore not required by the very definition of "not required". So you're only expressing an understanding of the language rather than an agreement with the arguer. You're simply acknowledging cognitive receipt of the conditional truth.

A more accurate expression of you perception would be "Yes, Frank, I understand".

[Peter_1]

You're not really agreeing with Frank, are you. You're simply stating that something not required is therefore not required by the very definition of "not required". So you're only expressing an understanding of the language rather than an agreement with the arguer. You're simply acknowledging cognitive receipt of the conditional truth.

A more accurate expression of you perception would be "Yes, Frank, I understand".

What is the technical meaning of this add?

I thought this was a refrigeration forum and not some sort of analytical psych forum where 'they' try to analyse what 'they' think you really want to say.

Never thought at the possibility that he's just saying what he's saying/posting, nothing more, nothing less, with no other message behind the answer?

[frank]

You're not really agreeing with Frank, are you. You're simply stating that something not required is therefore not required by the very definition of "not required". So you're only expressing an understanding of the language rather than an agreement with the arguer. You're simply acknowledging cognitive receipt of the conditional truth.

A more accurate expression of you perception would be "Yes, Frank, I understand".

This sounds like a reply from Marc :D

[frank]

Stupid me - I've just caught up with the postings in the Moderators Area :o :D

[Peter_1]

Me to, but that doesn't make me to change my post nor edit it.
Now it comes...........again.......all the abbreviations with 4 letters, NRIJ,.....describing the whole being of a person in just 4 letters.
A M A Z I N G
Could refrigeration be that simple......

[MRcoolingMAJIC]

Me to, but that doesn't make me to change my post nor edit it.


Hi, Peter_1.

What is the difference between changing a post and editing a post?

Thanx for the attention.

[Abe]

Is this place becoming all

schitzophrenic?????????

( I have never been able to spell that)

[frank]

Hi Raymond

Just re-visiting this old thread.

Did you manage to sort out the problem with your G series unit?

Any chance of an update - don't forget - we do site visits for reasonable reward :D

[Latte]

Hi Raymond

Just re-visiting this old thread.

Did you manage to sort out the problem with your G series unit?

Any chance of an update - don't forget - we do site visits for reasonable reward :D


Hi Frank,

First things first, ever thought of moving to Cambridge. I know a company looking for a good Daikin engineer, Unfortunatly they got me instead :D

Strangly got called back to the site today as the customer wants it SORTED :eek: OH REALLY !!!:rolleyes:

Now, can't be arsed to go through previous posts to see what i've put plus my dial up is getting slower and slower so would take me all night, what i think however

VRV has a cooling rating of 162.5
Indoor units add up to 212 so in theory should have never worked. Customer response "It used to work !"

Now the reception area of the building used to be seperate rooms but now its all gone open plan so i think more duty is being put on the unit. Also the unit is getting older (Arnt we all) and therefore probably having to work harder.

Now, i would like to reclaim, vac out overnight and regas. My problem then is, If i regas to the original VRV spec, surely this is enough gas to cope with a 162.5 capacity and not 212, therefore how much extra gas should i put in.

The problem its on a fully comp contract. Therefore my company doesn't want me to spend vast amounts on gas and it not clear the fault, the customer on the other hand doesn't care how often they call us as i doesn't cost them.

Oh the joys of the job

Regards

Ray

[frank]

Raymond


First things first, ever thought of moving to Cambridge. I know a company looking for a good Daikin engineer, Unfortunatly they got me instead
What's the PAY like :D

My daughter lives in St Ives so I'm a regular visitor to the area :)


Customer response "It used to work !"

Yes but did it work as it should?


Now, i would like to reclaim, vac out overnight and regas. My problem then is, If i regas to the original VRV spec, surely this is enough gas to cope with a 162.5 capacity and not 212, therefore how much extra gas should i put in.

You just can't overcharge a system that is out of manufacturers spec and expect the extra refrigerant to make it work :eek: It is out of design - full stop (based on your previous information). What you need to do now is come up with a solution to make the system work - not to just give the customer what he wants to hear.

Why not suggest to the customer that you ought to bring in a Daikin specialist to confirm the system is not installed to manufacturers specs and that to solve the problem will cost him some money? after all it's not your fault. Plus I may get to spend the night visiting the daughter :D

I'll only charge the same as Space Air or Daikin UK :)

[Latte]

Raymond


What's the PAY like :D

My daughter lives in St Ives so I'm a regular visitor to the area :)

Hi Frank,

Better speak to cooling-gurus about that one ;)

Looking at the site list i have, the main reception open plan area just off it have 2x40's 1x32 & 2x25. This if my math is righ is 162. There are two other units on this system on offices both 25's. I suppose the obvious answer would be to take these two off the circuit and put on their own condensing units.

Sounds simple but i expect it to be a pig of a job.

Anyway i have done my bit, i can only report what i find. Its up to those far higher up the ladder than me to come up with a solution

Regards

Raymond

[eggs]

VRV has a cooling rating of 162.5
Indoor units add up to 212 so in theory should have never worked.



I don't know too much about these things but...
Can you not size a vrv/vrf at 130% ? because not all indoor units will be switched on or running at 100% all of the time.

ie 162.5 +30% = 211 therfore,just inside the design limit.

cheers

eggs

[frank]

There are two other units on this system on offices both 25's. I suppose the obvious answer would be to take these two off the circuit and put on their own condensing units.


Unfortunately you can't put VRV indoor units on normal condensing units. Each VRV indoor unit has a built in EEV for refrigerant control and Skyair condensing units have the EEV on the outdoor.

Although you could use the 2 x 25's on a super multi but this would be more expensive than just putting in 2 new split systems.

[rbartlett]

Unfortunately you can't put VRV indoor units on normal condensing units. Each VRV indoor unit has a built in EEV for refrigerant control and Skyair condensing units have the EEV on the outdoor.

Although you could use the 2 x 25's on a super multi but this would be more expensive than just putting in 2 new split systems.


this is a R22 system so you're effed anyway...

cheers

richard

[frank]

I don't know too much about these things but...
Can you not size a vrv/vrf at 130% ? because not all indoor units will be switched on or running at 100% all of the time.

ie 162.5 +30% = 211 therfore,just inside the design limit.

cheers

eggs

Not quite Eggs.

In one respect the system can operate at 135% capacity which will mean that the indoor performance is reduced but the maximum index of the outdoor unit should not be exceeded. The high end index number relates to the 135% capacity so if you go over this then the indoor performance reduces even more as is evident by Raymond's system.

When designing a system you should calculate the indoor index numbers then select the outdoor to match - if some of your indoor units only run very little and you don't mind the temporary drop in performance then you can select the outdoor at a high index.

It's easier to understand with the selection charts in front of you :)

[Latte]

Hi Eggs,

I theory it could work like that, unfortunatly since they have gone all open plan the units are having to work hard all the time, especially as the receptionist thinks she's in spain and runs it at 25 all day long. I think the system would have coped before as units will have shut down in their smaller area's but no chance of that now:eek:

Regards

Fatboy

[frank]

Raymond

I found this troubleshooting guide for checking refrigerant charge

[Brian_UK]

Nice one, thanks Frank

[abdulazman]

RD
I was going to mail message you some details regarding the fault encounter but system was down. Here are the attachment. Mine are all hardcopies, hard to post the manuals down here. If you're here maybe I can hand it over to you.
Hope this things helps.