Fujitsu Icing Up

[dakesojo]

Hi all i was giving a call for a Fujitsu ASY24FBBJ on R410a ,it was totally iced up and all the way back to the compressor gas charge is correct the unit is in an server room and have been told it is the correct size for the duty in the room can anyone suggest why the unit may of iced up
thanks Dave

[NoNickName]

How do you know the charge is correct?
Since what point in the circuit the ice is showing?

[dakesojo]

the ice is all over the evap and right back to the compressor body not frosting, thick about 2 inch around suction pipe as to the gas charge i reclaimed it correct charge out for pipe run length so weighted correct back in

[NoNickName]

Is the TXV, filter or liquid solenoid iced up as well?

[dakesojo]

not to sure left the unit off to deice way to much ice could have sold it to the nearest pub,returning to job to recheck tomorrow

[monkey spanners]

I've seen this happen with some fujitsu asy17's on r22 fitted in server rooms a few years ago. Fault was caused by the compressor relay sticking on. Fujitsu supplied an uprated relay to be soldered on flying leads to replace the one on the board. Found room air temperature sensor cable tied to fan motor (sensor mounting bracket broken) on an amcor unit once, causing same fault. Is the indoor fan running ok? Temperature sensor saying rooms at 25c when its 0c ! compair resistance of sensor with that quoted by fujitsu. Hope this is of some help, let us know what you find.

cheers Jon

[Brian_UK]

Yep, sounds like the compressor has been running uncontrolled. Check the power relay circuit.

[Peter_1]

Fan indoor unit switching on/and off on it's internal overload or controlled by a faulty probe.
Clogged airfilter.
Dirty coil.

[ALONEI]

Hi
If it has some kind of frost protection like hot-gas bypass, cond' fan speed it worth chacking that it works ok

good luck

[Bones]

monkey spanners and brian is most likely correct about the relay that controls the compessor being stuck on, had the same problem here with ast7,9 and 12's that were used for the same application.

if the unit is a non-inverter then this would almost be your problem for sure.

Easiest way to check for shot realy is to turn the unit off at the hand piece and if cpompressor is still running thats your problem.

Else it would leed you to believe a sensor is reading incorrectly ;)