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gramcor
27-11-2012, 11:53 PM
I have five Daikin rooftop model UATYP 560AY1 with same problem :
in winter , in HEATING mode , defrost program is too short and ice cover the condensers .
( all the rooftops are mounted in same conditions )
If i change sensor positions on condensor , the defrosting period is the same .
I want to increase the defrost time ( if is possible...) , but i don't have technical manual for PCB .
Please help me with some informations ....

Thanks in advance

install monkey
28-11-2012, 12:20 AM
you need to comfirm the correct gas charge- or compare running pressures with the 4 normal units,also clean condenser coils can affect systems

gramcor
28-11-2012, 09:22 AM
Daikin technicians checked all parameters, all is normal , but did not have a technical solution. When increase the humidity at temperatures below 5 degrees C, ice accumulates progressively on condenser. PCB has a fixed duration of deicing, which reduces with the temperature measured by the sensor.

al
28-11-2012, 08:05 PM
You should be able to change the defrost frequency, i think it's a jumper wire? Alternatively if all else is ok, fit a timeclock, knock out indoor fan and connect to 4 way valve.

al

install monkey
28-11-2012, 11:56 PM
dip switch 1-8 doesn't allow for changing defrost duration, is there an economiser on the unit or a manual fresh air damper on it?