daikin

[Drew]

I have a diakin RY250KUY1 which is giving problems.
The outdoor fans will not run via the pc board .
On Daikins instruction I have replaced the outdoor pc board and this worked for one cycle (the fans ran)
They then shut down and the only way i could get them to run was to switch to emergency mode.( heat or cool)
I have checked my coil sensor and ambient sensor and they seem ok.
the system apparentley has never worked properley and i have been asked to sort it out. Without the outdoor fans the system runs low head and suction but does not trip out on any fault.

[Drew]

I have done a search on diakin outdoor fan faults and found this quote:

"If the controller isn't showing a fault then there isn't one. ;)

On the R407C condensing units the defrost timing 'learns' when to initiate.

I've had units with 2" of solid ice on the outdoor, no condenser fans running, compressor happily pumping and the indoor area close to set point. Daikin telling me that this is normal."

My system is on R22. Diakin have told me that at least one outdoor fan (out of the2) should be running.

Now I hear from the above quote that the outdoor fans dont need to run., but without them im only getting 20°c head and -20° suction. Doesnt seem right.

[martin102]

I have a diakin RY250KUY1 which is giving problems.
The outdoor fans will not run via the pc board .
On Daikins instruction I have replaced the outdoor pc board and this worked for one cycle (the fans ran)
They then shut down and the only way i could get them to run was to switch to emergency mode.( heat or cool)
I have checked my coil sensor and ambient sensor and they seem ok.
the system apparentley has never worked properley and i have been asked to sort it out. Without the outdoor fans the system runs low head and suction but does not trip out on any fault.

Is the problem in both heating and cooling ?

[Drew]

In Tasmania the ambient in to cold to run in cooling. I can only test the cooling in emergency cool mode and this, as the emergency heating is, is OK.

I didnt do the instal so i'd better check all wiring etc...

While running in emergency heat (with out door fans on) the HP started climbing and Ive realised that the ducts are a bit small so to eliminate high HP problems I have disconnected the ducts to the unit and now the airmovenent is free.
So i think Ive solved one problem and i'll get the HVAC guys to sort out the old ducts .
I dont think this fault is related to the outdoor unit fans not working in normal mode?
I cant believe a unit should be running at a 20°c head and a -20°c suction:eek:
At least one fan should be running?
What else can control the outdoor fans? Sensors? Indoor PC?

[Drew]

S2PH is a high pressure switch in the dicharge line of the RY250KUY1 unit. This switch will normally be made while running. If , in heating, the Head Pressure climbs too high, the awitch opens, turning off 1 outside fan. This lowers the suction pressure , in turn lowering the head.

If this pressure switch fails and is open circuit on start up neither of the outdoor fans will start.