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View Full Version : Fujitsu cassette h/p condensors icing up !



stevo
18-02-2006, 09:12 PM
Hi; We installed 3x 12kw h/p cassettes into a school I.T dept(auy45) last summer, they work well, either on heating or cooling. Problem came after staff came back after xmas hols & found two of the roof top mounted condensing units were badly iced up, there is no fault code either on the remote or on the c.u. board. The pipe runs are within the pre charged criteria (R410a), they are group controlled, and are set to auto. It has been suggested they may be short of gas, but they were completly iced from top to bottom,almost fouling the condenser fan(6-7" from coil) air of a.h 50 deg + C. I feel these units have never been on defrost since installation ! Wiring checks out ok, Could this be a faulty coil sensor from new, or possibly a c.u board , seems a coincidence two out of three units are faulty. Any ideas will be greatly recieved. :)

Brian_UK
18-02-2006, 11:37 PM
I'd go along with your thoughts on faulty boards and/or sensors.

As it's new kit I would suggest a warranty replacement of all electronics.

aeb200
19-02-2006, 02:56 PM
what temp is indoor set to?
last month I had a daikin unit that completely iced up.
found indoor unit set to 30oC and outdoor running continuously!!!
according to daikin this just couldn't happen as outside air sensor / electronics defrost coil.

I set the unit to 23oC and fitted a lockable box around controller so no one could fiddle- Haven't had a call since

stevo
19-02-2006, 03:41 PM
what temp is indoor set to?
last month I had a daikin unit that completely iced up.
found indoor unit set to 30oC and outdoor running continuously!!!
according to daikin this just couldn't happen as outside air sensor / electronics defrost coil.

I set the unit to 23oC and fitted a lockable box around controller so no one could fiddle- Haven't had a call since


Temp set to 25oC on auto, but the coil should surely de frost automatically whatever the set point is ! I am not sure at the moment if the o.u coil just senses temp or weather it is a timed procedure as well ! If i freeze down the o.u coil sensor should this bring it onto a defrost mode ? anyone !! :)

Andy
19-02-2006, 04:20 PM
Hi Stevo:)
my bet would be on a badly placed sensor the one that controls defrost and frost protction:)

Warrenty issue I would say.

Kind Regards. Andy

stevo
19-02-2006, 04:39 PM
Hi Stevo:)
my bet would be on a badly placed sensor the one that controls defrost and frost protction:)

Warrenty issue I would say.

Kind Regards. Andy


Thanks Andy :)
I will have a good look around, but my reckoning would be to replace board & sensors, Can't think what else it can be , but would be good to prove it without the possibility of another repeat call out. cheers ; steve

rbartlett
19-02-2006, 07:03 PM
weigh in the correct charge just in case. then check

if not it usually defrost board and/or sensors

we just had 2 out of 5 lg's doing self same thing to the point they smashed up the condenser fan blades

cheers

richard

stevo
20-02-2006, 05:35 PM
weigh in the correct charge just in case. then check

if not it usually defrost board and/or sensors

we just had 2 out of 5 lg's doing self same thing to the point they smashed up the condenser fan blades

cheers

richard

Hi Richard; was the gas charge at fault on your L.Gs then, or was it boards/sensors ? :)

davej
20-02-2006, 10:54 PM
for your information mr bartlett Lg know they have aproblem with fans peed controllers on some units and it is accepted as a wanrranty repair, we have info from them to the extent that they will send their engineers to repair systems.

rbartlett
03-03-2006, 03:34 PM
Hi Richard; was the gas charge at fault on your L.Gs then, or was it boards/sensors ? :)


Both..

cheers

richard