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Daikin VRV 3 pipe changing mode
RSEYP10KJV
We are looking at a 3 pipe Daikin K series R407c which seems to be changing mode every 15-20 minutes. it's like a defrost or an oil recovery . We think the outdoor fans slow but still run.Sensors check out within range.We measured the charge as correct.
All the indoor units are on full heat.
The unit starts up normally and the gas pipe gets up to 50+c then all of a sudden it 'changes over' and the gas pipe goes cold. Doesn't last for more than about 5 minutes then goes back to 'normal' and the cycle starts again...
Has anyone got any pointers on how we go about finding the fault (we don't have a checker btw) and the rooms are simplified controllers
Thanks
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Re: Daikin VRV 3 pipe changing mode
Hi Multisync,
When you say all indoors are on full heat are you 100% sure they were all set to heating only mode (not auto with set point increased). The reason I ask is that this sounds like the unit is continually entering equalization in order to allow a BS box to change mode. I have encountered this a few times usually caused by discharge air from an indoor influencing return air/wall/controller sensor (bad installs).
Possible causes,
Cassette indoor too close to wall (common in small offices) resulting in recirculation of discharge air into return air path.
Unit blowing discharge air onto wall sensor/controller sensor
Ducted units with discharge ducting damaged or missing allowing discharge air to blow into the return of another unit.
This usually results in the indoor unit bs box changing from heating to cooling to heating to cooling…….
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
VRVIII
Hi Multisync,
When you say all indoors are on full heat are you 100% sure they were all set to heating only mode (not auto with set point increased). The reason I ask is that this sounds like the unit is continually entering equalization in order to allow a BS box to change mode. I have encountered this a few times usually caused by discharge air from an indoor influencing return air/wall/controller sensor (bad installs).
Possible causes,
Cassette indoor too close to wall (common in small offices) resulting in recirculation of discharge air into return air path.
Unit blowing discharge air onto wall sensor/controller sensor
Ducted units with discharge ducting damaged or missing allowing discharge air to blow into the return of another unit.
This usually results in the indoor unit bs box changing from heating to cooling to heating to cooling…….
Yes you are right about auto full heat. .It's a small hotel installed 2000. Nothing has changed afaik.
The engineer did mention something about him having concerns about one fan coil 'playing up'. Another engineer was on site yesterday working on another system and we phoned and asked him to run one indoor at a time to see if we could find if an individual indoor unit is causing this. He wasn't really involved in this before so we guess a bit unsure of what/why we were trying to achieve, plus he was really tied up trying to get the other system running.
I guess we need to run it on test mode and see or ensure they really are all on heating only ..
Thanks so far and we'll get back on this.
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Re: Daikin VRV 3 pipe changing mode
Multi,
I meant to ask you if the preheat/defrost icon is displayed on remotes when unit changes/stops heating?
Also there is no need to select test mode just make sure all units are set to heating only mode.
Is there no way you beg borrow or steal a service checker for a couple of hours? This would save you so much time, allow you to see exactly what’s happening and the auto address of the problem indoor if my suspicions are correct. Hotels are always a head ache trying to get access to rooms (BTW you really need to get a checker for VRV fault finding).
If not do have an old centralised controller? This could be connected at the outdoor and would allow you to lock the operation mode and to have control of indoors units from outside. However you still need brief access to programme group numbers if this has not been done in the past.
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
VRVIII
Multi,
I meant to ask you if the preheat/defrost icon is displayed on remotes when unit changes/stops heating?
Also there is no need to select test mode just make sure all units are set to heating only mode.
Is there no way you beg borrow or steal a service checker for a couple of hours? This would save you so much time, allow you to see exactly what’s happening and the auto address of the problem indoor if my suspicions are correct. Hotels are always a head ache trying to get access to rooms (BTW you really need to get a checker for VRV fault finding).
If not do have an old centralised controller? This could be connected at the outdoor and would allow you to lock the operation mode and to have control of indoors units from outside. However you still need brief access to programme group numbers if this has not been done in the past.
I can confirm the pre heat logo comes on during this problem. Would this mean the short cycling is not likely the cause?? He did say with 4 indoor units on (out of 10) the cycling happend less frequently.He did not have full access to all 10 rooms -hotels eh?
Sadly I attempted to buy a checker from a friend of a regular here. All was agreed until he stopped answering my call(s)..not too sure what went wrong there...
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Re: Daikin VRV 3 pipe changing mode
This is the problem with Daikin VRV.
In aplication like hotel when access to all indoor units is always a problem then you really need to be able to get data from each indoor unit like,,, mode / set temp / EEV opening / return air temp / gas & liquid refrigerant temps from a remote location.
If other manufacturers VRF system is used you can get all that data from every indoor unit by service engineer setting at the outdoor circuit board & outdoor circuit board LED display.
No need for any service checker laptop computer.
The outdoor unit compressor slow down for pressure equalisation every time an indoor unit changes mode has been a big disadvantage for the VRV system.
Look at the new BSV box & you will find that instead of soleniod valves there is now 5 EEV valves !
Trouble shooting any problem with the new BSV boxes without the service checker I suspect will be an even larger challange.
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
multisync
I can confirm the pre heat logo comes on during this problem. Would this mean the short cycling is not likely the cause?? He did say with 4 indoor units on (out of 10) the cycling happend less frequently.He did not have full access to all 10 rooms -hotels eh?
Sadly I attempted to buy a checker from a friend of a regular here. All was agreed until he stopped answering my call(s)..not too sure what went wrong there...
The preheat icon will be displayed when ever the outdoor is in equalization/defrost/oil return/preheat. I would defiantly check for short cycling if the problem is occurring every 20minutes or so.
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
VRVIII
The preheat icon will be displayed when ever the outdoor is in equalization/defrost/oil return/preheat. I would defiantly check for short cycling if the problem is occurring every 20minutes or so.
We will deffo check that first.
Thanks for all the assistance I will get back with this either way...
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
Thermatech
This is the problem with Daikin VRV.
In aplication like hotel when access to all indoor units is always a problem then you really need to be able to get data from each indoor unit like,,, mode / set temp / EEV opening / return air temp / gas & liquid refrigerant temps from a remote location.
If other manufacturers VRF system is used you can get all that data from every indoor unit by service engineer setting at the outdoor circuit board & outdoor circuit board LED display.
No need for any service checker laptop computer.
The outdoor unit compressor slow down for pressure equalisation every time an indoor unit changes mode has been a big disadvantage for the VRV system.
Look at the new BSV box & you will find that instead of soleniod valves there is now 5 EEV valves !
Trouble shooting any problem with the new BSV boxes without the service checker I suspect will be an even larger challange.
Thermatech
Do you have a checker as we may need assistance to quickly get to the bottom of this ...
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
Thermatech
This is the problem with Daikin VRV.
In aplication like hotel when access to all indoor units is always a problem then you really need to be able to get data from each indoor unit like,,, mode / set temp / EEV opening / return air temp / gas & liquid refrigerant temps from a remote location.
If other manufacturers VRF system is used you can get all that data from every indoor unit by service engineer setting at the outdoor circuit board & outdoor circuit board LED display.
No need for any service checker laptop computer.
The outdoor unit compressor slow down for pressure equalisation every time an indoor unit changes mode has been a big disadvantage for the VRV system.
Look at the new BSV box & you will find that instead of soleniod valves there is now 5 EEV valves !
Trouble shooting any problem with the new BSV boxes without the service checker I suspect will be an even larger challange.
Theratech,
Your obviously a Mitsi man at heart :D.
But you can’t blame the equipment if you encounter limited access to indoor units; personally I think it’s a case of which ever equipment you are most familiar with and personal preference, Daikin also has a lot of plus points over Mitsi and vice versa. Most of the engineers I know say Daikin VRV is far easier and quicker to commission (I can see a poll being started here).
The fault finding process obviously differs between manufactures and a Daikin service checker is only a tool that allows you view and record all operation data simultaneously but as with any tool it’s only as good as the engineer using it.
The current VRVIII heat recovery system no longer has to equalize when a bs box changes mode, this is now done by slowly operating the motorized valves in the box (the additional valves you refer to). Allowing full capacity to all other indoors when a box changes mode.
The outdoor also has independent heat exchanger control which only allows 1 heat exchanger to carry out a defrost cycle while the other continues to operate as an evaporator. The unit can then continue supplying hot gas to indoors, resulting in reduced capacity loss during defrosts cycle.
P.S. Have you changed your problem box yet? Did it cure the noise?
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
multisync
Thermatech
Do you have a checker as we may need assistance to quickly get to the bottom of this ...
Multi I’ll bet you Thermatech has a Mitsi checker :D
If you were a bit closer I could have help you out no probs, how’s the weather down there today? It’s snowing here just now.
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
VRVIII
Multi I’ll bet you Thermatech has a Mitsi checker :D
If you were a bit closer I could have help you out no probs, how’s the weather down there today? It’s snowing here just now.
He has both from what I understand.
I believe Daikins lack of digital display and 'user friendly access to info' on the outdoor unit is very outdated. The push buttion sequencing was S.O.T.A in 1990 but sadly lacking these days.
VRVIII was their ideal opertunity to come into the 2000's but they missed the boat again.Intrepreting Checker is no easy task and again very old fashioned in layout. It really needs time and familarity to fully comprehend the data.
I was going to buy Toshi Dyno Doctor (which is really good btw) but was told few use it as the display usually give enough to diagnose the problem.
Clear blue skys at the moment :D
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
multisync
He has both from what I understand.
I believe Daikins lack of digital display and 'user friendly access to info' on the outdoor unit is very outdated. The push buttion sequencing was S.O.T.A in 1990 but sadly lacking these days.
VRVIII was their ideal opertunity to come into the 2000's but they missed the boat again.Intrepreting Checker is no easy task and again very old fashioned in layout. It really needs time and familarity to fully comprehend the data.
I was going to buy Toshi Dyno Doctor (which is really good btw) but was told few use it as the display usually give enough to diagnose the problem.
Clear blue skys at the moment :D
Hmmm think you Mitsi guys are ganging on me now :confused:.
I know where your coming from some of the other manufactures VRF/VRV’s logic and diagnosis is easier to get your head round but I could say manually setting rotary switches to address every indoor/bc box/controller is so dated Daikin done away with this in 1990.
On newer vrv units (vrv2&vrv3) it is also possible to retrieve faults, fault history, retry history and able to identify the fault location, all from the outdoor PCB.
ie, which hp switch has caused a trip, which fan motor is causing a fault and which module has an error in multi application. However this can be quite complex to understand unless it’s demonstrated and explained, but this helps keep us in a job..
It would be interesting to see the Tosh doctor software but I’ve heard it would take more than a doctor to get there 407c vrf to operate correctly.
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Re: Daikin VRV 3 pipe changing mode
Currently I am an independant VRF specialist & provide on site technical support for ac contractors for commissioning & trouble shooting mainly Mitsubishi City Multi but also Hitachi Set Free VRF & sometimes reluctantly Daikin VRV.
But have been in the trade 33 years & worked for a number of the major manufactures in possitions from technical service tengineer / training engineer up to service manager.
Between 1992 & 1998 I think I must have commissioned easily more than 100 Daikin VRV systems.
From day to day over the last 12 years I work with different ac contractors all over the UK with trouble shooting & commissioning site visits.
A few weeks ago I was on site with a Toshiba distributor service engineer & he was showing me how to get all the system data from the Tosh VRF outdoor unit.
I dont normally look at Tosh systems but basically its much the same process to Hitachi & Mitsubishi VRF systems. You can monitor live data from any indoor units in the system from the outdoor unit so there is no direct need for a laptop computer.
Even so the first thing I do on site is connect the laptop computer to the system not just because I have got it but because it just is a bit quicker & easier. When you are 50+ you dont need to be legging it all arround a building like you could when you were 21.
Whatever manufacturers system you are working on.
Whatever experiance & training you have.
Whatever laptop monitor / service checker you have.
If you can access live operating data remotely without having to go around the indoor units you can often locate most problems faster & have a better overview of the complete system operation.
At the end of the day most contractors dont have any monitor / service checker equipment / laptop computers for service engineers.
So some manufacturers like Mitsubishi Electric Hitachi Toshiba make all of the system operating data available for the service engineer at the outdoor circuit board which can be most helpfull in locating most problems faster. Historical recorded data from when the system last stopped on a fault can also be really helpfull with locating intermittant faults which often only happen when you are not on site.
Unfortunately its not so easy with the Daikin VRV.
Thats why contractors are always asking me to do Daikin VRV trouble shooting site visits & more often than not I decline.
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
Thermatech
Currently I am an independant VRF specialist & provide on site technical support for ac contractors for commissioning & trouble shooting mainly Mitsubishi City Multi but also Hitachi Set Free VRF & sometimes reluctantly Daikin VRV.
But have been in the trade 33 years & worked for a number of the major manufactures in possitions from technical service tengineer / training engineer up to service manager.
Between 1992 & 1998 I think I must have commissioned easily more than 100 Daikin VRV systems.
From day to day over the last 12 years I work with different ac contractors all over the UK with trouble shooting & commissioning site visits.
A few weeks ago I was on site with a Toshiba distributor service engineer & he was showing me how to get all the system data from the Tosh VRF outdoor unit.
I dont normally look at Tosh systems but basically its much the same process to Hitachi & Mitsubishi VRF systems. You can monitor live data from any indoor units in the system from the outdoor unit so there is no direct need for a laptop computer.
Even so the first thing I do on site is connect the laptop computer to the system not just because I have got it but because it just is a bit quicker & easier. When you are 50+ you dont need to be legging it all arround a building like you could when you were 21.
Whatever manufacturers system you are working on.
Whatever experiance & training you have.
Whatever laptop monitor / service checker you have.
If you can access live operating data remotely without having to go around the indoor units you can often locate most problems faster & have a better overview of the complete system operation.
At the end of the day most contractors dont have any monitor / service checker equipment / laptop computers for service engineers.
So some manufacturers like Mitsubishi Electric Hitachi Toshiba make all of the system operating data available for the service engineer at the outdoor circuit board which can be most helpfull in locating most problems faster. Historical recorded data from when the system last stopped on a fault can also be really helpfull with locating intermittant faults which often only happen when you are not on site.
Unfortunately its not so easy with the Daikin VRV.
Thats why contractors are always asking me to do Daikin VRV trouble shooting site visits & more often than not I decline.
Thermatech,
I joined the forum to hopefully pass on and gain a little knowledge with a bit of friendly banter thrown in for good measure, I certainly wasn’t questioning your technical knowledge or experience.
I can understand your point of view and think the mitis VRF is a good system, but for every 10 things mitsi VRF has over daikin I could provide 10 points where daikin VRV is superior to mitsi (but really don’t see the point). Every engineer is entitled to there own opinion and personal preference.
In my opinion the quality of a unit is decided by how well the system operates, system efficiency and of course how reliable it is.
Well you wouldn’t say a bmw car is superior to a merc because the merc mechanic uses a laptop to diagnose an engine management fault, especially if the merc is much better to drive.
So, if you decline any future trouble shooting site requests for Daikin units up this neck of the woods give me a shout I’d be glad to handle them :)
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Re: Daikin VRV 3 pipe changing mode
If you do buy/borrow a service checker, I'd suggest making sure that the engineer that goes has a BRC1D52 controller with him, he will then be able to allocate an airnet address/room number to each indoor unit, in the event that it has not been done allready. From that point on, any engineer that goes to site won't need so much time to familiarise himself with the system.
On the debate (have no preference)regarding manufacturers, I can remember being able to access all sorts of data from the original Hitachi set free systems, I think that its fair to say that they were ahead of their time.
Cheers
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
multisync
We will deffo check that first.
Thanks for all the assistance I will get back with this either way...
Hi Multisync,
Did you get to the bottom of why the units was changing mode?
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
VRVIII
Hi Multisync,
Did you get to the bottom of why the units was changing mode?
Crumbs we are having so much trouble on that site it's not funny :D
On another system they have been waiting for a new inverter compressor. That had a U4 error over the weekend. Our guy went to site, played around checking if all indoors had power on etc. Suddenly it came back on.
Back today to start the reclaim and compressor change but were stopped before starting as another system was not heating properly (historical bad airflow design) + they wanted to have another look at the U4 error (no point changing the compressor if it won't run anyway.)
However half way through that one and a worker noticed oil dripping through the ceiling tile another system had split a liq line! So the compressor/investigation never got started.
The change over system faulting was only noted by the engineer who was looking at another system in error. He mentioned it as a problem but the site guy's are saying they haven't had one complaint from that area so it's being left till we can get the rest sorted...:confused:
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
multisync
Crumbs we are having so much trouble on that site it's not funny :D
On another system they have been waiting for a new inverter compressor. That had a U4 error over the weekend. Our guy went to site, played around checking if all indoors had power on etc. Suddenly it came back on.
Back today to start the reclaim and compressor change but were stopped before starting as another system was not heating properly (historical bad airflow design) + they wanted to have another look at the U4 error (no point changing the compressor if it won't run anyway.)
However half way through that one and a worker noticed oil dripping through the ceiling tile another system had split a liq line! So the compressor/investigation never got started.
The change over system faulting was only noted by the engineer who was looking at another system in error. He mentioned it as a problem but the site guy's are saying they haven't had one complaint from that area so it's being left till we can get the rest sorted...:confused:
Multi,
It sounds like you’ve had one of those days :confused:
At least you didn’t need to dig your way through the snow to get up the street on the way home :rolleyes:
U4 errors can be real pain on older installs, especially when it’s an intermittent fault.
You will probably be aware of the most common reasons for a U4;
- Mains power off at indoor/bs/outdoor
- Loose live or neutral connection
- Mains power has been switched off/on but system fails when reinitializing (turn power off/on again and hold down reset button for 10sec)
- Bad connection on F1F2 comms lines
- Mice or rats chewing into comms cables!
- If it’s an R22 KJ outdoor unit the small green interface pcb that f1f2 cable connects to has been known to cause probs (not applicabe for 407c).
- Faulty indoor/bs/outdoor main PCB (never had this with intermittent U4 error tho)
- K series units can be very slow to recognize a U4 error
- U4 errors will auto reset when comms are reestablished
Let me know how it all works out :)
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
VRVIII
Multi,
It s
ounds like you’ve had one of those days :confused:
At least you didn’t need to dig your way through the snow to get up the street on the way home :rolleyes:
U4 errors can be real pain on older installs, especially when it’s an intermittent fault.
You will probably be aware of the most common reasons for a U4;
- Mains power off at indoor/bs/outdoor
- Loose live or neutral connection
- Mains power has been switched off/on but system fails when reinitializing (turn power off/on again and hold down reset button for 10sec)
- Bad connection on F1F2 comms lines
- Mice or rats chewing into comms cables!
- If it’s a KJ outdoor unit the small green interface pcb that f1f2 cable connects to has been known to cause probs.
- Faulty indoor/bs/outdoor main PCB (never had this with intermittent U4 error)
- K series units can be very slow to recognize a U4 error and
- U4 errors will auto reset when comms are reestablished
Let me know how it all works out :)
Took me 1 1/2 hrs to go 3 miles this afternoon. :D
We've had rats chew the comms cable in a hotel once and a few of the others here and there. This is a strange one and we can only hope that it holds till Christmas.
The install is only just (and I mean 3 weeks just) 3 years old. It's sad they are failing like this. I won't tell you what the UK facilities Director thinks of Daikin after this and an even worse site up north somewhere.... :cool:
Just to cheer you back up I am mid swap on a Tosh SHRM: 3 condensers multiplexed and so far in 2 years 3 compressors failed out of 6 !
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
multisync
Took me 1 1/2 hrs to go 3 miles this afternoon. :D
We've had rats chew the comms cable in a hotel once and a few of the others here and there. This is a strange one and we can only hope that it holds till Christmas.
The install is only just (and I mean 3 weeks just) 3 years old. It's sad they are failing like this. I won't tell you what the UK facilities Director thinks of Daikin after this and an even worse site up north somewhere.... :cool:
Just to cheer you back up I am mid swap on a Tosh SHRM: 3 condensers multiplexed and so far in 2 years 3 compressors failed out of 6 !
Multi,
How far up north is the other site, you never know I might know it, have these sites lost many compressors? Do you know it they all failled with the same symptoms (seized/down to earth/open circuit)? Were the systems checked after compressors were replaced? Not that we have ever replaced a comp without checking solenoids, EEV’s and thermistors ect ;)
If you get the time to dig deep enough you can usually find the cause. It might be worth drilling the faulty comp, drain the oil, check oil condition and measure the oil volume (should be 0.8 ~1.5L). It can sometimes give an indication to what’s going on.
I’ve visited various sites where the end user is slating the equipment, when most of the problems encountered were due to install issues; wrong pipe sizes installed, piping over max run length, wrong application, units under sized (usually by a consultant wearing a Teflon coat), refnets positioned vertically, crossed piping, crossed wiring, recirc of air flows, debris in pipe work, no OFN used when brazing, bad set up commissioning…………..
I’m not saying this is the case on your problem sites or manufactures never have problems with unit components, software and things but they do seem to get blamed no matter why the problems have occurred.
Are your Tosh units still under warranty? Could you not complain to them and requested they send an engineer to check the unit (it always helps if you have an order pending for leverage) :D
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Re: Daikin VRV 3 pipe changing mode
I can confirm it was all installed by a D1 dealer. I PM the rest
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Re: Daikin VRV 3 pipe changing mode
Hmm, Interesting...
A simple question of a system "changing mode" goes in to a "my is better than yours" conversation.
Now, back on track.
You say the discharge pipe reaches 50degrees and the outdoor unit goes in to what could be a defrost mode every 20 minutes.
Has anybody checked the gas charge/pressure sensors and so on?
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Re: Daikin VRV 3 pipe changing mode
Quote:
Originally Posted by
The Viking
Hmm, Interesting...
A simple question of a system "changing mode" goes in to a "my is better than yours" conversation.
Now, back on track.
You say the discharge pipe reaches 50degrees and the outdoor unit goes in to what could be a defrost mode every 20 minutes.
Has anybody checked the gas charge/pressure sensors and so on?
It is possible but I doubt the problem is defrost related as the minimum time between defrosts for the unit is 30 minutes.
To enable a defrost: 30 minutes accumulated compressor run time + HP <22b + coil temp < calculated value (depends on ambient) for 5min.
As I said previously you would really need to connect a service checker to verify what’s happening.
