Hot VRV fan coils,

[...CooLMan...]

Hi and help,

I've spent my morning looking at a VRV with hot fan coils. The set point is 22 deg on all the coils but the room is about 30deg. I checked the coil temperature ind it was about 44 degrees. The staff are sweating and I don't know what would be causing it to get too hot.

Any thoughts?

Thanks

[install monkey]

local controllers, contactor welded on compressor?

[Andy AC]

Have you got a fresh air inlet drawing cold outside air over the return air sensor in the machine?

[...CooLMan...]

All local controllers have been removed. Total control from Itouch. Not sure about the fresh air. Windows were opened when people got hot. Cassettes are mounted below the ceiling.
No fault codes.
Not sure about contacts on the compressor. How would I check that?

Cheers

[install monkey]

turn the condenser off then if when u switch it on the compressor starts immediately then its welded

[...CooLMan...]

Nice. Cheers IM. Would that mean a new compressor?

[...CooLMan...]

Would the system shut down at schedule timer Off if it was welded?

[RusBuka]

Name of the equipment you are trying to repair by look?
Have you any soft for that equipment? number of impulse on EEV

[install monkey]

compressor would still run but indoor fans would stop

Would the system shut down at schedule timer Off if it was welded?

[install monkey]

no just a new contactor around 80 quid for a daikin contactor, 35quid for a telemechanique/danfoss from an electrical wholesaler

Nice. Cheers IM. Would that mean a new compressor?

[...CooLMan...]

Unfortunately no software,

@ Install Monkey. The fans had stopped in the room but you could feel the heat. Can I test the contractor on anyway?

[install monkey]

has the problems arisen since removal of the local remote controllers?- hook up a controller and check the setting modes to ensure cassette is set for operating on return air sensor only not average of return and remote controller sensor. setting should be 10-2-02

[install monkey]

check condensers to see whats running- even if you isolate the outdoor you wont see the contactor welded as they have a sticker covering the position, it wont be on the inverter compressor, will be on the direct on line comp, check the wiring diagram to see which contactor u need to be looking at

Unfortunately no software,

@ Install Monkey. The fans had stopped in the room but you could feel the heat. Can I test the contractor on anyway?

[RusBuka]

mmm i dont understand, its VRV system, or only one AC...

if its VRV, when only Toshiba smmsi work on heat with fully closed EEV on indoor units, other brands open eev a little bit, because they need recover oil from indoor unit.

[...CooLMan...]

Not sure if removal of controllers and rise in temp started together or not. I'll bung a controller back on the system Monday and check.
Also check if the compressor keeps running.
Thanks.

[install monkey]

daikin vrv,need to know how long its been in for,how many bs boxes,how many indoors, model number on outdoor, actual return air temps and setpoints on I touch, any vam units, remote sensors-so at the moment only a few rough ideas on whats faulty

mmm i dont understand, its VRV system, or only one AC...

if its VRV, when only Toshiba smmsi work on heat with fully closed EEV on indoor units, other brands open eev a little bit, because they need recover oil from indoor unit.

[RusBuka]

Forgotten that only Daikin called VRV

[...CooLMan...]

7 ceiling mounted cassettes on Bev boxes. Open plan office with 4 wall mounts in little offices. Been in for about 2 years. Rxyq10m9v1b linked to a rxyq12m9v1b.

[RusBuka]

dude you need checker and soft. if you dont have it, you dont see what happend in system. Daikin its not MHI))
but mente-pc and super link checker can make wonders too)

[install monkey]

21hp vrv 2 - as you removed the remote controllers I take it you've had problems with temperatures in the open plan area- all the cassettes in the open plan area need to be operating together- if you have 7 cassettes and 7 bs boxes and set them for 22 auto then theyre gonna be fighting each other- you need to go into the I controller and enable fixed point control as opposed to average of all indoors and in the group page on the I touch the top unit is designated the master. theres a few settings to set a 2 deg diff for changeover, you got an I touch manual?

[...CooLMan...]

No manual! I'll try and download one from somewhere

Cheers

[install monkey]

check ur e mail- I sent u I touch!! manual

No manual! I'll try and download one from somewhere

Cheers

[...CooLMan...]

Thanks mate

[install monkey]

coolman u have mail- again

[...CooLMan...]

Whoa!

Thanks Install Monkey much appreciated!

[...CooLMan...]

Software sounds expensive man

[r.bartlett]

local controllers, contactor welded on compressor?

It would fault on a newer system if that was the case would it not...?

Sounds like the system is locked on 30 C heat.

[frank]

On the iTouch controller, you can read the Mode, Set point and actual temperature.

What are these readings?

[...CooLMan...]

Mode=Heat, Set=23, temp=28.3 ( on some of the fan coils, 26/27 on others )
The room is hot but the fans didn't seem to be blowing when I was there. No radiators or other heat sources.

[install monkey]

the filters are clean aren't they??indoor fans will tick over in low speed in heating mode and speed up as the coil temp increases, usually above 33deg - (read off the local remotes in setting mode 41 002)- its prob going to be a minor setting change somewhere

[...CooLMan...]

Filters are clean. Setting 41 002 was high (42). I think problem started after Daikin changed some settings on Itouch. Something to do with the mode setting. Apparently there is no auto option for this type of system. I'm not sure what it was set on. There are 5 floors (zones) on the system. Each zone runs off its own outdoor unit, this is the only zone with fault.
I'll check Itouch Monday.
Cheers

[install monkey]

any vrv with each indoor having its own bs box can be set in auto- unless they grouped all the indoors in the open plan area- 2 pipe vrv you have to designate 1 indoor as a master and then its either heat or cool- or if they fitted the mode select switches wired to the outdoor- but that's old school, see page 37 onwards changeover settings and temperature limit and heating optimization settings on I touch

Filters are clean. Setting 41 002 was high (42). I think problem started after Daikin changed some settings on Itouch. Something to do with the mode setting. Apparently there is no auto option for this type of system. I'm not sure what it was set on. There are 5 floors (zones) on the system. Each zone runs off its own outdoor unit, this is the only zone with fault.
I'll check Itouch Monday.
Cheers

[...CooLMan...]

I've got FXUQ71MAV1 - FXUQ125MAV1 connected to BEV boxes on a 2 pipe system. Apparrently (according to Daikin) theses cassettes are for splits and need to be used with BEV Boxes.
I had a look at the Remote Control before it was removed and there was no Auto function. Maybe the control had been locked out.

[frank]

In the group control, (iTouch) you need to make sure that all of your relevant fan coils are assigned to the group so that the schedule settings are actually registered with the fan coils evertime a schedule setting times activates.
If some of the fan coils are not included in the group, they can't/won't respond to the instruction.

From your readings, it seems like the room is just drifting above the set point and as you are locked in 'Heat' mode, the fan coils cannot change to cooling mode to control the room.

[...CooLMan...]

Unfortunately I wasn't sent back there today. Wall mount installation today.
The building has been switched to winter schedule which doesn't allow cooling. It's just the one floor over heating. Strange!
I'll keep you posted?
Thanks for all the advice. Hopefully I'll get a chance to try it out.
Cheers.