Daikin twin cassette problem!

[langy]

Got asked to do a service on a working Daikin RZQ100B7V3B to 2 x FCQ50B7V1 cassettes. Switched system off at outdoor isolater (no indoor switches) I asked apprentice to clean the filters and coils, Then switched system back on to check air temps.
Controller then shown several different fault codes as I switched off and on to investigate.
U4,UF,C9,UA.......After the fourth switch off and on, ....because I didn't switch off straight away, I was suprised to see that the system was running and cooling, as asked via the remote, but still showing a fault code and light flashing on the remote.
Scratched my head and then watched the fault code disappear.
Now system seemed to be working ok.
I had another job to do so, I decided to leave it running and come back later to check over.

Whilst away I got a call saying it wasn't running at all.

I returned to find one indoor unit fan running, but nothing else, whatever mode I put it in!

The indoor unit that the fan was running on, was the one that the controller was connected to, I tried connecting controller to the other unit.....now the fan started working on that unit and stopped on the other. With the help of Daikin technical ,went through the setting checks
but could not get system working. Daikin think it is probably the outdoor pcb.
Has anyone had a problem like this????? They only wanted it servicing, now they think Ive damaged their air con

[install monkey]

have u checked indoor terminals,make sure the connections are ok,as number 3 connection on the interconnect as you say u tried the controller on both indoors and the indoor fan operates,but the other doesnt, ur controller is connected to 1 indoor and no3 is ur comms line between the other indoor and outdoor signal. i can send u a manual

[install monkey]

sent u manual

[Dunger]

First wire the controller to each unit individually, go to service code 45 and ensure that the UNIT NO. is set to 0. If it isn't then change it to 0 and confirm the setting.
Once you have done this to both units (both UNIT 0) wire the controller to one unit only and DO NOT link the two indoor units on P1P2.
Once you have done this go to service code 11 on the controller and select code 0-02 (twin split), once this is done all faults should disappear.
Just to confirm wiring should be 1,2,3 from outdoor to 1st indoor and 1,2,3 from 1st indoor to 2nd indoor. Controller only wires to P1P2 on one indoor and no link to second indoor.
Hope this helps

[frank]

First wire the controller to each unit individually, go to service code 45 and ensure that the UNIT NO. is set to 0. If it isn't then change it to 0 and confirm the setting.
Once you have done this to both units (both UNIT 0) wire the controller to one unit only and DO NOT link the two indoor units on P1P2.
Once you have done this go to service code 11 on the controller and select code 0-02 (twin split), once this is done all faults should disappear.
Just to confirm wiring should be 1,2,3 from outdoor to 1st indoor and 1,2,3 from 1st indoor to 2nd indoor. Controller only wires to P1P2 on one indoor and no link to second indoor.
Hope this helps

Good answer Dunger, and I agree, this is the way to do an install, but this problem has only appeared after a service visit, where the power has been dropped. I assume from the original post that the system was working OK before the service.

I would suspect either a loose connection somewhere or a dodgy pcb.

[langy]

Yeah checked terminals....re-made em and tried new interconnecting cable. 240 ac between 1and2 varying dc voltage15 to 25 between 2and3 both indoors and outdoor....controller voltage approx 15 dc, even tried new controller. Tried each indoor to outdoor seperately (suggested by Daikin tech)
Yes please to the Manual.

[install monkey]

langy=check ur aol acc( others are available) its a 16meg file

[langy]

langy=check ur aol acc( others are available) its a 16meg file

Cheers Matey

[install monkey]

no problem, any consilation i had a daikin 5kw inverter doing a server room,i fitted it 6yr ago, it had been serviced regular and last week i cleaned the condenser coil as it was like a blanket of dust ,took running current,temperatures all ok,i didnt even turn it off, 6hrs later compressor siezing and now its only 50quid extra to change the enitre system as opposed to the compressor,inverter pcb and diode stack-i think they have a built in self destruct pir!!haha

[langy]

Thanks for the input guys

[still learning]

comms rooms , never get a rest realy, they run 24 /7 / 365 a day, so 6 years old is 12 years run imho.
and some last longer than others

[Improver]

Langley I have in the past had to repair an A.c system that had recently been serviced and I found that the maintenance engineer got evaporator cleaner on indoor unit p.c.b causing fuse to blow. I wonder if the apprentice may have done the same thing here.

[langy]

Langley I have in the past had to repair an A.c system that had recently been serviced and I found that the maintenance engineer got evaporator cleaner on indoor unit p.c.b causing fuse to blow. I wonder if the apprentice may have done the same thing here.

No mate I make sure that doesn't happen.

It was the outdoor pcb...... Replaced it and all sorted