Daikin VRV central control

[Chillybilly]

Got another blinding one on the daikin VRV system ,it seems that the 2 units that cool the server room in this office set at (19oc) keep switching over to heat and ramping the temp up to 25oc .The cental controller for the building seems to switch them as it displays heat !!!
Any ideas ???

[multisync]

Got another blinding one on the daikin VRV system ,it seems that the 2 units that cool the server room in this office set at (19oc) keep switching over to heat and ramping the temp up to 25oc .The cental controller for the building seems to switch them as it displays heat !!!
Any ideas ???

A vrv in a server room..not recommended :-)

What version of IManager do you have ?

[frank]

Sounds like you have heat mode set up in the daily schedules

[james10]

A vrv in a server room..not recommended :-)

It amazes me as to the thinking behind the designers it must be the cost engineers who cross the splits off the list

[brunstar]

it may be a good idea to set the central controller up to NO CHANGE, this way if there is a schedule in place the set point or mode will not change.
This unit should be locked into cooling and not auto mode.
The other thing, for this to change over like this the indoor unit may be short cycling, like hitting a cabinet and recirculating the cold air over the return air sensor.
Depending on what unit you have you may want to install a remote sensor to avoid this..

[techguy]

Hey
Set the indoor units up as cooling only or just delete these two addresses off the central controller. So they run independantly of central control. I am not that familiar with Daikin Kit. But this can be done on SANYO/TOSH/MITSU so I'd be amazed if Daikin don't have this function.

I'm sure one of the Daikin Tekkies in here could help with either of these set up's

[Chillybilly]

Interegated the controller yesterday ,dont know why they used VRV for the server room ,only angle i have is the rest of the building is VRV .

Regards the controller and setup,the offending units are in cool only mode with a sp of 19oc ,they are not influenced by any time strategys in the controller so should not heat at all ,When the system does go into heat mode it does it without following any patterns ,eg one day in the morning the next day at dinner time .It logs no High temp alarms so i think it believes its doin the right thing ,all very odd ...............

Might be the time to get the Daikin man in with his laptop and do a software upgrade ,the version in the controller at present is around 4 years old it seems ........Willpost the result

[VRVIII]

Interegated the controller yesterday ,dont know why they used VRV for the server room ,only angle i have is the rest of the building is VRV .

Regards the controller and setup,the offending units are in cool only mode with a sp of 19oc ,they are not influenced by any time strategys in the controller so should not heat at all ,When the system does go into heat mode it does it without following any patterns ,eg one day in the morning the next day at dinner time .It logs no High temp alarms so i think it believes its doin the right thing ,all very odd ...............

Might be the time to get the Daikin man in with his laptop and do a software upgrade ,the version in the controller at present is around 4 years old it seems ........Willpost the result

I take you have an I touch controller and not the older type centralised contoller, what is the controller software version? This can be viewed in system - version information.

You could also check:

Verify 100% none of the start timers have been set with a target of ALL in schedules section.

Could the units in question be part of a heat cool change over group? (check in change over settings section)

Could the units be set up with Teperature limit settings?

[wozza]

It is possible to have Comms room on VRV, Daikin now have a code you put in for comms room applications.

I would personnally make sure the comms room units are in there own group, so make sure the schedules are not labelled ALL.

You can also lock the controller into cool locally in setting 1B-002 then you have to press the 4 buttons for 5 secs.

I would also prohibit any use of the local controller through the I-Touch.

[amerillove]

Fresh air must also be supplied without increasing energy consumption and central management and control facilities have gained in importance, particularly for medium to large sized buildings.~

[wardy2]

I have come accross a few lately were they run the vrv system in the day time for the comms room and turn them off at night and run the comms room on splits consultants love this idea (i dont mind it either if it gives me work)

[martinw58]

is the system a three pipe or heatpump if two pipe heatpump system units will not cool if systm is in heating

[Makeit go Right]

I have come accross a few lately were they run the vrv system in the day time for the comms room, and turn them off at night and run the comms room on splits.

That is a way of dealing with the Comms Room wanting cooling all weekend/over night, while the offices are switched off. It would be worth giving Daikin all the info on this system in case the %load in the computer room is too small for the bigboy condenser.

On a recent Mitsi system, the computer load was quite small in relation to the condenser, and having that comms room calling for cooling through the weekend (and overnight) while the rest of the system was off, gave problems for the compressor. We warned the customer (in writing) about the damage going on and offered a separate split or 2 for the computer room, but they would seemingly prefer to do the upgrade after they loose a compressor on the vrf. Up to them.

If you have this kind of situation, it might be better to have a few offices kept running with the comms room to reduce the problem. But Daikin should be able to confirm whether it is an issue or not.

As for designers choosing to include a comms room on a vrv/f system, I think they generally try to avoid this. But after handover, often a tenant moves in and builds a comms room under a general air-conditioner, or in a room intended as an office.