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jutty
04-08-2005, 04:51 AM
I am In Perth Australia and I have a FDYP145DL external unit (don't have the internal unit number here) fully ducted system installed. Now in summer the unit works great the inverter side of things goes great guns cycles up and down like it should keeps the house nice and cool. But in winter the unit is shor cycling badly. The unit will ramp up to full speed from off to full speed maybee stay there for 10 mins then just shutdown, no inverter slow down just power off. Then 10 mins later start back up to full speed then run for 5 mins and shutdown. The temp inside never gets to what it shoud be and because of the amount of time it's on and off temp throughout the house is hit and miss. Also we have to set the internal fans to be off when the outside unit is off otherwise we get cold air blowing around when the outside unit shuts off.

It gets worse as I suspect that because the unit is operating either flat out or off it is also going into defrost mode 10 times a night.

I have had Daikin out and they said flat out it is short cycling. I get the installer out and I suspect all I get is bull****.

I have changed settings (on their advise) so that it takes the temp from the remote unit (control panel) but I have another temp guage that says it is at least 2-3 degress below what the temp is set for sitting right next to the remote unit.

They also advised to set the internal air flow to low and change it to something called low staic?? I keep having arguments with them about the unit not operating as an inverter unit but all they care about is the temp inside the house which is not right anyway.

He also tells me that the temp is not done by a thermister but based on pressure, is this correct??? I do know that there is a thermister in the remote unit (control panel) but is the temp really determined by pressure or is that bull****??

Basically in winter when the unit is heating the unit runs for 10 mins at a time then shutsdown and at night with outside temps at about 13-5 degrees it also goes into defrest mode every 3 or 4th cycle ie unit on unit off unit on unit off then unit on staight off into defrost mode.

I'm just trying to find out what other things I can try and to see what bull**** the guy is trying to tell me.

Oh one other thing daikin said is that one of my vents is to colse to the return air which the installed denies.

Winter unit is **** summer is great no issue.

Sorry for long thread but very frustrated.

smileypete
04-08-2005, 10:17 AM
Hi,

Try setting the indoor unit fan to low as you've been advised, does that help?

Also try blocking the vent that's near the return to see if that helps.

An inverter will cycle if the load is below the low end of it's capacity range.

It does sound as if something could be amiss, but you should try following Daikins advice first, as they should have experience in how they work.

Does your installer have a copy of the service manual? There may be some diagnostic LEDs which will tell if anything is wrong.

If the installer doesn't have the service manual that's not a good sign... :rolleyes:

cheers,
Pete.

Temprite
04-08-2005, 10:41 AM
What did you have to do to set the wired control to sense?(what buttons were you told to press).
Maybe it is still sensing from return air.

Try taking the air temp at the return air grille and see what temp you get.

Where is the return air in relation to the supply air ducts.?

Are the filters clean?

frank
04-08-2005, 08:21 PM
Hi Jutty and welcome to the forum

Daikin are very good bits of kit but like everything else they can and do go wrong (sometimes :D )

If you want to pay my air fare then I would be more than willing to come across and have a look at the system for you. :D

Joking aside, It sounds like a sensor fault. All electronics need feed back to provide conrol. If a sensor is "out of calibration" then it sends the wrong information to the processor and you end up with a faulty system. Check all sensors against manufacturers data.

The compressor speed is determined by the suction pressure, but as your system starts and then runs for a few minutes I would suspect that gas charge is ok. If the gas charge was not correct I would expect the compressor to kick back quite soon.

jutty
05-08-2005, 02:40 AM
Daikin themselves have never sugested anything. They came out on behalf of the intsaller and were not "allowed" to talk to us or discuss anything they had to report back to the installer. The installer is the one who has been advising of what changes to make. They faxed me a part copy of the service manual that showed all the commands to program the control pannel.

Don't have in front of me but I currenlty have the following settings done (can't give the numbers don't have paper in front of me). Remote sensor active, low static mode, low fan speed, internal fan off when external unit off.

1 Return air vent (which is the one that is always blowing air no matter what zones are on) is 2 - 2.5 metres away and another vent from one of the bedrooms is maybee 3 metres away. Might get a scan of the plan and post it.

Return air grill is clean. The install was only done 18 months ago and the problem has been there since the first summer. No problems ever in winter.

Problem seems to be related to heat rising just overloading the sensors I don't know.

Can someone explain how the inverter unit are supposed to cycle. Do they cycle based on the temperature ie when temp gets to within 1 degree of desired then slow down. Saw some posts in regards to a setting that can be used to view what the unit things the return air and remote temps are want to see what it thinks the temp is at shutdown.

bobjob
05-08-2005, 05:19 PM
hi Jutty

Your Daikin model FDYP145SDL is not used here in the UK but i guess that it should have many of the feature as the present Daikin inverter Sky Air ducted systems used here.

If it is a Sky Air unit the control is done by the thermisters only and there is no pressure transducer to change the frequency of the compressor.
Like most Daikin condensing units it aims for various targets.
It measure the actual temperature difference away from the set temperature on your remote controller and if it is in the heating mode it will set the frequency of the compressor to get a certain discharge temperature.

you will need a tool called a Sky Air checker to see this happening as the frequency of the compressor changes to the information supplied by the various indoor/outdoor and discharge sensors.

You can check if you are having a problems with hot air short cycling by monitoring the sensor temperatures from the remote controller
If you need information on how to do this, i will put it on a new message.

Regards Bob

Temprite
05-08-2005, 10:32 PM
hi Jutty

Your Daikin model FDYP145SDL is not used here in the UK but i guess that it should have many of the feature as the present Daikin inverter Sky Air ducted systems used here.

If it is a Sky Air unit the control is done by the thermisters only and there is no pressure transducer to change the frequency of the compressor.
Like most Daikin condensing units it aims for various targets.
It measure the actual temperature difference away from the set temperature on your remote controller and if it is in the heating mode it will set the frequency of the compressor to get a certain discharge temperature.

you will need a tool called a Sky Air checker to see this happening as the frequency of the compressor changes to the information supplied by the various indoor/outdoor and discharge sensors.

You can check if you are having a problems with hot air short cycling by monitoring the sensor temperatures from the remote controller
If you need information on how to do this, i will put it on a new message.

Regards Bob

You are pretty close to the mark Bob. The out door unit is a 14.5 Kw inverter similar to sky air units. Indoor unit I believe is Australian or at least Australia had input into the design.

The Sky air checker you refer to over here they call it a transmission monitor, Connects to the lines between the units.

Jutty If you are not satisfied Ring Daikin back. I know that if our customers are not satisfied we continue until they are. Unless they are asking something unreasonable.

I know of a chap called Dennis in Perth Daikin tech support he seems pretty clued up.

tonto
07-08-2005, 10:39 AM
Jutty,

I too am in Perth also, and every time I have had a drama with Daikin units I have called Dennis at Daikin technical support in Perth and he has been more than helpful with any enquiries... The only problem is that you can only get in contact with him after 2.00pm as before then they direct you to the eastern states tech support.
Hope this helps

BillyBenz
23-07-2007, 05:34 AM
Don't worry you are not alone.... We bought the Daikin FDYQ160M model in July last year. You are absolutely correct the Air Con cycle works very well and is also very quite. No humming noise.

The heating on the other hand is absolute cr*p.:mad: The humming noise it makes is heard throughout our 30 sq house... I seriously can't believe the neighbours haven't complained yet... :confused:

You can't leave it on too late as our unit seriously humms like a jet engine.... So you freeze.:mad:

I hate it so bad that I'm now getting ducted heating fitted next week. Should have done that in the 1st place, however got sucked in.:(

Daikin and the installer say it's fine... but how can it work when it turns off every 25 mins for 10 mins....??? Do other brands work like this?? Forget the controller we have it on 24Degs otherwise it blows cool air... not bad when's it shows 10degs on our guage. Oh well expensive mistake...:(

So in summary I would never recommend it for heating... stick to ducted heating....;) The Air Con is great though.