fault on a daikin Roundflow

[marc5180]

Got called to a fault yesterday at a restaurant that we have just taken on. the fault was no cooling from the indoors.

After looking around i found that the system was a twin with refnets (not 2 seperate circuits). Both indoor fans were running although there was no cooling. I went to the condensor and the compressor was running, condensor fans were running so i decided to put on my guages.

On the suction i had 4 bar and the discharge was 15 bar (R410A), i went down to the van to get something then i came back up and the pressures had dropped to 1 bar suction and 4 bar discharge......easy, i thought....it's short of refrigerant. As it was late on when i got the call i told the manager i would be back tomorrow with a reclaim bottle to sort it out.

Today i went back, i recovered 400g. the standard charge was 4.3kg for up to 30m.. whoever installed this didn't write on how much additional refrigerant was added (this really does annoy me). The pipes disappear through ceilings, walls and floors but i think the total run is about 40m for the 2 of them. I pressure tested the system up to 25 bar and connected my gauge lines to the service ports as i always do, checked everywhere for a leak and i found a small leak on a schrader near the 4 way valve. Once it was fully vacced out i recharged but only managed to get in 2.5kg, i tried to start it up but i couldnt get it to run for long enough. The condensor fans would start up then the compressor but it would only run for a few seconds. I spoke to a guy from daikin who told me how to put it on test, i did this and managed to get the standing charge in it.
However when it was running the high side kept shooting up to 35 bar very fast as though there was a blockage somewhere, i checked that the expension device in the condensor was working and also the 4 way valve- they both were. When i turned the unit off by the isolator the standing pressure was 22bar, i told this to the daikin guy and he said there must be nitrogen still in the system. He asked me how i had pressure tested it, so i told him and he said i should never pressure test from the service ports because nitrogen can get trapped ( it's news to me) he advised to reclaim and vac out again- which i did

[marc5180]

When i went to recharge it i managed to get the full 4.3kg in it and i started it up but in test mode, the pressures looked ok again a little low but the suction coming back was cold, i tried to add a little more refrigerant and i added 0.5kg more, however the next minute the suction pressure started dropping and dropping until it was at 1 bar, the liquid pressure was 5 bar.
I went insided to check the indoor units and the master unit fan was running but the slave unit fan wasnt running for some reason, there was power to it but it weren't running. I stripped the unit down to look at the connection on the back of the motor and where it plugs into the board and it seemed ok. When i went back to the master indoor it was coming off at 7DegC although it was on forced test mode.
I started to look at the wiring and found p1 + p2 from the master going to the controller and also to the slave but in the slave p2 wasn't connected. How do these units communicate with each other???
Because the restaurant was getting busy by now i had to leave but before i left i went to the out door and after taking it off test watched it for a few minutes and again the Fan, then the compressor would start for about 10 seconds then go off, then come back on after 3 minutes, then it would go off again....... It's been a long day i i need some help

[marc5180]

Sorry condensor model number is an RZQ140B8W1B and the indoors are the 71type and they only have 1 controller for the 2 of them...... Sorry for the long post

[marc5180]

Marc, if i understand correctly you have one cond. unit feeding two indor units by using refnets.Good enough if this is the case the pipe run after the refnet is it identical to both indoor machines or the one that you have problem has the longer pipe run.One more thing is the refnet installed et a level with maximum 30% slant...
As this is not a VRV you can't have two different lengths of pipe after the refnet me thinks.

Yes one condensor feeding 2 indoor cassette units and using refnets. The refnet is near the first cassette unit which then branches off and then goes to the next cassette unit about a furthur 7 meters away.
The refnet is level and isn't raised at all.

[puddleboy3]

Hi Marc

Your indoor units should be of equal distance from the refnet connection. As for the remote controller wiring the P1/P2 from the controller should only go to one of the fan coils. If you had two different models ie four way blow and floor mount the controller wiring should go to the fan coil with the most features swing lourver etc. I suggest you sort out the remote control wiring and ensure that you have field setting 11-0-02 set in so that the system knows that its a twin setup.

Hope this helps

[puddleboy3]

Also it sounds to me like the system is shutting down on freeze protection.

[marc5180]

Hi Marc

Your indoor units should be of equal distance from the refnet connection. As for the remote controller wiring the P1/P2 from the controller should only go to one of the fan coils. If you had two different models ie four way blow and floor mount the controller wiring should go to the fan coil with the most features swing lourver etc. I suggest you sort out the remote control wiring and ensure that you have field setting 11-0-02 set in so that the system knows that its a twin setup.

Hope this helps

The thing is though, this has been running for about 1 year, another engineer went around christmas time and carried out the maintenance on it. i've spoken to him and he says it was definatly working, which leads me to think how can there be a problem with the wiring and also the refnet issue. Why would the indoor fan not run?? i mean it could also be a problem with the indoor board couldn't it?

The condensor runs as though its going into pump down mode with the hp staying around 15bar but the suction dropping down to 1bar.

[Daikin=Overated]

...............[When i turned the unit off by the isolator the standing pressure was 22bar, i told this to the daikin guy and he said there must be nitrogen still in the system. He asked me how i had pressure tested it, so i told him and he said i should never pressure test from the service ports because nitrogen can get trapped ( it's news to me) he advised to reclaim and vac out again- which i did]


Did you energize the 4 way valve when reclaiming/charging. I.e did you supply power to the control circuit? If it's got LP protection it won't fire up so don't worry, if it hasn't simply remove the pot connections!

That's why Daikin are very specific and always have been to be fair regarding pressure testing procedure.

With the four way valve non-energized you will either have trapped gas or non condensibles held in the pipe work within the condenser.

Did the dials on your gauges bounce consistently when observing pressures? This would be conclusive if so, or was it a nice steady rise??

Also do take readings from the secondary set of internal service valves provided for true readings, not the external valves!!

Best of luck.

J.

[marc5180]

Hi when i reclaimed the refrigerant i turned the power off by the isolator, so there would have been no power to the control circuit.

With regards to the pressure, it rose consistently right up to at 1 point 38bar, as the fans work off temperature though, the 2nd fan should have kicked in to bring the head pressure down but it didnt even come on.

I left it the other day and the suction pressure got down to 1 bar with the discharge at about 15 as though its pumping itself down.

[marc5180]

Anyone? I'm going back to the job tomorrow first thing.

[stuartwking]

Hi marc. I agree with Puddleboy3,.
First i would Sort the wiring to the second unit and see if it performs any better. I guess you will have to reclaim and recharge with fresh gas and since you will have the gas out you should really sort the pipe run out. I wouldnt worry to much about your condenser fans right now.
For sure get the install to spec and take it from there. Keep us posted,.. Have a good one.
stu.

[freezy]

hi

Whats all this about equal pipe distances from twin's refnets. I have seen loads of twins with different lengths. I thought there was a limit but its determined by difference in lenghs from a calculation?

[jdhservices]

Hi, I had a similar wiring issue recently. C/u would nt recognise the two f/c s on a twin. Slave had 240 at the interconnecting terminal, but no led blinking. Turned out to be a 5A fuse in a small black holder next to the 1234 connections. Re set and it should recognise both units. Hope this helps, if its not too late.

[marc5180]

Hi, I had a similar wiring issue recently. C/u would nt recognise the two f/c s on a twin. Slave had 240 at the interconnecting terminal, but no led blinking. Turned out to be a 5A fuse in a small black holder next to the 1234 connections. Re set and it should recognise both units. Hope this helps, if its not too late.

Checked the HAP terminal going onto each board which proves there was power going on to them

[Jase]

What operating pressures temperatures have you recorded so far. I would expect around 100-120psi Ps and 300psi+ Pd. You may have restriction in the system

Jase

[marc5180]

When i first starts up it runs at around 5 bar (75psi) suction and around 20 bar (300 psi) discharge. when it was running on friday i did notice that both liquid and suction in the condensor were starting to frost over heavily........ Theres definatly no blockage in the system, i blew through with nitrogen today and undid all flare nuts to scheck that nitrogen was coming through.

[Daikin=Overated]

When i first starts up it runs at around 5 bar (75psi) suction and around 20 bar (300 psi) discharge. when it was running on friday i did notice that both liquid and suction in the condensor were starting to frost over heavily........ Theres definatly no blockage in the system, i blew through with nitrogen today and undid all flare nuts to scheck that nitrogen was coming through.

Where was it frosting up on both suction/discharge??
From the service valves and pipe work back to indoor, or within the condensor?

Shouldn't be frosting up on discharge in the condenser unless theres an EEV fitted in there somewhere. Again a drawing would identify these things.

[Daikin=Overated]

I think a wiring diagram would really help shed some light on the control circuit if anyone can provide one for our viewing pleasure?

I thought the fan control was operated through pressure switches (they used to be on the older models) and not through the PCB?? Do you mean the PCB switches the fans through relays via the pressure control switches??

You may still not be achieving the correct head pressure because of restrictions/non -condesables as previously suggested, or that the presuure switch isn't functional hence second fan not engaging.

Have you checked to see what pressure the fans should be engaging, then testing to see your getting voltage through the switch to the fans-then you can say relay on control circuit is defective?

I had a fault with an old Daikin sky air (same fan control issue) after charging the system. Found the relay wasn't switching the fan's in. Checked the tracks on the back of the PCB and found a dry solder joint going to the relay coil..........check, and double check!


J

[marc5180]

I think a wiring diagram would really help shed some light on the control circuit if anyone can provide one for our viewing pleasure?

I thought the fan control was operated through pressure switches (they used to be on the older models) and not through the pcb?? you may still not be achieving the correct head pressure because of restrictions/non -condesables as previously suggested hence second fan not engaging.

Have you checked to see what pressure the fans should be engaging, then testing to see your getting voltage through the switch to the fans?
Sorry if you have and I haven't read the post properly-it's getting a little long.

J

I know it is getting long, just want to be sure i include everything that i have tried. lol

Both the condensor and evap fans work off temperature not pressure. There are no non condensables in the system for sure, it has been vacced out and recharged twice, that i am certain of.

[coolments]

Hi Marc, just want to concentrate and add comment to what is happening to the refrigeration side of this problem, do not rule out the possibility of moisture in the system, I have had a system before that would run ok then gradually seem as though it had a blockage and moisture was the problem as ice particles form on the inside of the EEV during operation causing a blockage, then defrosting when the compressor stops. This caused the unit to do all sorts of weird stuff as its sensors were reading wrong and pressures went haywire.
Water ingress had occured in this instance due to a cracked suction flare nut, the suction would freeze (naturally as you would be evapourating below freezing point with a unit Short Of Gas) at some point ran into a vacuum and sucked in moisture as the suction pipe defrosted, then the system would be reset and the process would start over again intergrating more moisture in there.
2 attempts were made by another engineer to clear this moisture by blowing with nitrogen and filter driers to no avail. I then attended site and removed the compressor and empitied out the oil into a 2 pint glass container, it settled and seperated to reveil almost 5% of the oil was water. So new oil, nitrogen purge, triple vac and oversize drier was installed, we then attended site two weeks later and tested the system to find moisture still there, did same procees again and next time all was well, this was 5 years ago now and the units still working.
Point I am saying is that you state in an earlier email that you found a leak on a shrader was this shrader on the suction side, and I assume the frost starts after the EEV if so there is a good chance of you having a similar problem as we had.
One pointer to check for this is to see if the unit takes longer for the pressure to equalise than you would expect it to as the ice in the EEV defrosts equalistation will speed up. Good luck

P.S dont forget new rerfigerant also every re-charge.

[Freecool]

Marc : So where do you pressure test from then.

Freecool

[Daikin=Overated]

Marc ...........what's the latest?

[marc5180]

Coolments- the leak that i found was on a schraeder on the discharge on the 4 way valve, when the system was under pressure i tested all the flare nuts for any sign of a leak and none was found. I guess the only way for me to prove this is to leave under pressure overnight but i dont think i'm going to get the chance.

Freecool- I pressure tested from the service ports where you connect the suction and liquid pipes to but i should have used the internal schrader ports inside the condensor. on this system there was one on the 4 way valve and one near the EEV.

[marc5180]

Marc ...........what's the latest?

I went to the suppliers to get a price this morning just for a new indoor board, got the price then gave it to our office to fax it over to the client who i was hoping would approve it and i could get it ordered next day delivery, meaning that i could go back there tomorrow. However when i spoke to the office they said that they are going to claim under the warranty from the company that put it in. If that is the case then i wont know what the problem is/was

[puddleboy3]

Outdoor fans are controlled by both outdoor air temperature and reading from pressure transducer.

If the inverter PCB was faulty you would have a fault code @ the remote plus when attaching the inverter tester to sky air systems they dont have an inverter test function so the PCB thinks there is a fault as there is no current draw. I know that with splits if you put them in to fan only test this runs the inverter components with out going out on a fault. Cant remember if this works on Sky air?

I would be concentrating on why your slave unit is not running! Also in service mode settings you can only set the master! ie mode 41 for reading sensors you cant read anything from the slave! If you can then your not on a twin system.

Think you'll find that there is something silly wrong stand back from your system and have a coffee!

Get your hands on the Daikin transmission monitor for a better idea of whats happening again I think that if your system is shutting down with no fault codes it will be something to do with freeze protection!

Happy days

[S_Line]

Cant you get the PArt direct from Daikin? As its still under warranty ?

Poor Customer will have to go through all this again with the original company who installed the system

[marc5180]

Cant you get the PArt direct from Daikin? As its still under warranty ?

Poor Customer will have to go through all this again with the original company who installed the system

Yes we can get it straight from daikin, but we have been told that the original installers will be doing it so thats that. I guess i'll never know now.

[marc5180]

Just an update, we have been instructed to carry out the repair of this unit ( i know it's been 3 weeks) but the company who installed it has gone bust so we have managed to get the indoor board from daikin under warranty.
I'm not looking forward to going back, fitting the new board and still having problems
Any suggestions to help me get the matter sorted once and for all?

[Contactor]

Get a service checker on this unit as you will be able to rule out a lot of the suspected control problems in about five minutes - thermistor readings, expansion valve control, p1 / p2 wiring, faulty boards etc etc. I try and avoid calling Daikin, as you say you'll get different answers every call. I've found someone experienced who helps via email, muh less hassle... They will send a wiring diagram via email as well.

[frank]

Get a service checker on this unit as you will be able to rule out a lot of the suspected control problems in about five minutes - thermistor readings, expansion valve control, p1 / p2 wiring, faulty boards etc etc. I try and avoid calling Daikin, as you say you'll get different answers every call. I've found someone experienced who helps via email, muh less hassle... They will send a wiring diagram via email as well.

Contactor

You can't attach the Daikin Service Checker to a split system. The services checker works on the F1 F2 connections and the DIIINET comms. The RZQ14 doesn't have F1 F2 comms.

Do you mean a Comms Tester?

[Contactor]

You can connect directly to the PCB using optional cable(s).

[stuartwking]

Marc you must be enjoying this one?!
I agree you can put a service checker on your split,.
Have you had the slave unit running with any of the boards?.

[marc5180]

Marc you must be enjoying this one?!
I agree you can put a service checker on your split,.
Have you had the slave unit running with any of the boards?.

Just been looking at this post. Since i posted last time Daikin sent out a new indoor board but it was the wrong one. Then they sent out the right board but i have been busy all week in london so they sent another guy to fit it but when he got there to fit it, the controller started flashing up a fault code. When he rang daikin they told him that another part should have been sent that clips onto the board but it wasn't in the box...... It's becoming a joke.

So now we have to wait until this connector is sent for plugging onto the board, then we will have another go

[marc5180]

Marc you must be enjoying this one?!
I agree you can put a service checker on your split,.
Have you had the slave unit running with any of the boards?.

I dont have a service checker but i agree it would be useful. How would i try and get one of these? Can they be bought from diakin?

I haven't had the slave unit running when the boards have been swapped but i have had the slave unit running when i swapped the controller over from the master onto the slave.

[stuartwking]

There is no such thing as defeat!!!, Have you tried using a controller on each unit or just a different controller?,

[marc5180]

Can you explain what you mean by this?

On a twin split, the 3 core + E connects from the outdoor unit to the first indoor unit and then to the second indoor unit.

The controller, P1 P2 connects to one (any) indoor unit only. Comms between the indoor units is carried out via interconnect 3 (on R410A systems). There is no Master/Slave configurations to do.

Have you checked out the interconnect wiring for crossed wires?

Yes i tried using a controller on each unit and both indoors came on although the compressor did not.

[Contactor]

Can you wire each unit as a single split and test run, will this help pinpoint your problem(s)?

[marc5180]

I have also tried this but the outdoor wont run because the capacity is too large with only 1 indoor connected up.

[puddleboy3]

This is a strange one! Maybe you have already tried this but I thought I would suggest anyway. Switch the power off to the system and connect the remote controller to the slave unit and enter service code 11-0-01. Power the system off and connect to the master unit and set the same service code 11-0-01 this would mean that as far as both indoors are concerned they are stand alone systems as they would be from the factory. Also when you have the controller connected check mode 41 and read the two sensors return air and coil. Cant help feel that it will be someting silly thats wrong here!

[marc5180]

Daikin have agreed to come out to have a look at it but on the 30th of June (next monday). I'll be meeting them there to see what the fault was.
It will be something simple, i know it but i can't find it.

I'll let you know when i find out so nows the time to have a guess and lets see who is right.

[transit 1]

hi there well i would say outdoor boards replace them cheers and good luck

[airefresco]

I'm saying faulty remote.

[skags]

sounds like it is not saving that it s a twin not a split to me.. dunno whose fault that is ? is that the control or indoor pcb ? as both units fans will go when it is master. if you set it then go back has it saved ? and could it have reverted back to factory settings (single split) when powered down for so long while you where reclaiming refrigerent, good luck be interested to hear what the problem is

[acbloke]

Just my tuppence worth - The address setting can be cured if you put a controller back on both units and clear memory. Then set them up as twin unit again - Daikin engineers can talk you through this. Just reseting power doesn't work. As for the fridge side of things ie seems to be pumping down on start up I had a similar problem recently. I tried blowing through with nitrogen no problems but still blocking when started up. Turned out to be the strainer located just before the EEV that was partially blocked. Replacement solved problem. Hope this helps.
Oh and I agree - there is no such thing as defeat!!!

[marc5180]

Just my tuppence worth - The address setting can be cured if you put a controller back on both units and clear memory. Then set them up as twin unit again - Daikin engineers can talk you through this. Just reseting power doesn't work. As for the fridge side of things ie seems to be pumping down on start up I had a similar problem recently. I tried blowing through with nitrogen no problems but still blocking when started up. Turned out to be the strainer located just before the EEV that was partially blocked. Replacement solved problem. Hope this helps.
Oh and I agree - there is no such thing as defeat!!!

Update, The Daikin engineers arrived today and were as baffled as i am, they checked everything that i had previously checked- inteconnecting wiring, mains wiring, fan motors, boards, thermisters , controllers etc. They were on the phone for hours to their bosses going through the settings on the controllers.
What i did notice is that when they altered a setting on the controller sometime the "UA" fault would appear, now to get rid of this it was just a case of returning the setting to the original one and the fault would go. So now i'm thinking that maybe the new board that i changed didn't need changing it was just that i put a wrong setting in that Daikin gave me.. all i would have needed to do is change the setting back.

Next he set about trying to run them individually so he disconnected 1,2 and 3 from the master baord and wired straight through onto the slave unit. He then powered down then powered back up, waited for the "88" to disappear and the controller came on on cooling 16DegC but the indoor fan didnt run. He was miffed and couldn't understand it, so i went into the settings on the controller and found 21-2-02 which he had altered. I changed this to 21-2-01 and straight away the indoor fan came on. By this time it was 5.30pm and after speaking to his bosses they have suggested that the other indoor board (the slave) gets replaced. I'm not confident and i told him but he's sure thats all it can be.

The part will be ordered tomorrow and hopefully it will be delivered on Friday , when i will be able to go back, again!

[sinewave]

Bet the customers wishing they'd paid for decent gear now like an LG!

[marc5180]

Went back to site the other day and fitted the new board so we have changed both master and slave indoor PCB's. As soon as the board was connected it started up and then brought on the compressor and began to start cooling, pressures looked fine and air off each indoor was 11DegC.
Problem solved- still dont understand it though

[stuartwking]

At long last.
hope the customer is happy.
Bet your glad to be clear from that mightmare.

[tobyprv]

Marc just read the thread. you had any joy yet? sorry no help but very interested to no what happened

[justchill]

id get a daikin engineer in , then it would be his problem !