garyjh24
11-06-2013, 10:19 PM
Hello,
Has anybody come across this:
Unit Installed :
Fujitsu Ducted Unit : Model No: ARYA45LCTU
Twin Fan Condenser : Model No: AOYA45LCTL
Supplies : Recording Studio
Recently had a few call outs for the above system, customer complaining room unit is unable to maintain temp. Every time we visit we find the room down to temp and the system is working well, air on/ off has 10-12 degrees differential, refrigerant pressure good etc and room down to temp.
Investigated again yesterday, arrived on site at 10:00am, checked operation, air on/off, refrigerant pressures/air flows, coils cleans/filters clean/ no restrictions in ductwork/ compressor operation etc. Had a few other jobs on site so managed to monitor operation/studio temp for around 4 hours - all good, studio maintaining 21 degrees. Left site at 14:50, 15:50 receive call from client that Studio temp has risen to 27 degrees.
Returned to site at 16:30, finally I am able to experience the unit at fault. The unit is running for approx 4 minutes, compressor fully ramped up. Once 4 minutes of running is up the unit cuts out for 2-3 mins then runs again for 4 mins (controller set to 18 degrees, room temp at 25.5 degrees)
Suspected that maybe a frost protection is causing this, checked the evaporator coil, no signs of frost or excessively low temp at coil so frost protection cut out is not the cause. The units return air Temp is controlled by the controller, changed this for another controller to make sure it's not the sensor but problem still occurs.
Possible that it is the evaporator coil thermistor that is playing up or maybe the FCU PCB?
Attended site again today for another matter so checked on the system again, unit is now running well again today. Studio is down to temp, unit is running as it should.
Obviously an intermittent fault, thinking of replacing the FCU PCB and Evap Thermister.
Has anybody come across this:
Unit Installed :
Fujitsu Ducted Unit : Model No: ARYA45LCTU
Twin Fan Condenser : Model No: AOYA45LCTL
Supplies : Recording Studio
Recently had a few call outs for the above system, customer complaining room unit is unable to maintain temp. Every time we visit we find the room down to temp and the system is working well, air on/ off has 10-12 degrees differential, refrigerant pressure good etc and room down to temp.
Investigated again yesterday, arrived on site at 10:00am, checked operation, air on/off, refrigerant pressures/air flows, coils cleans/filters clean/ no restrictions in ductwork/ compressor operation etc. Had a few other jobs on site so managed to monitor operation/studio temp for around 4 hours - all good, studio maintaining 21 degrees. Left site at 14:50, 15:50 receive call from client that Studio temp has risen to 27 degrees.
Returned to site at 16:30, finally I am able to experience the unit at fault. The unit is running for approx 4 minutes, compressor fully ramped up. Once 4 minutes of running is up the unit cuts out for 2-3 mins then runs again for 4 mins (controller set to 18 degrees, room temp at 25.5 degrees)
Suspected that maybe a frost protection is causing this, checked the evaporator coil, no signs of frost or excessively low temp at coil so frost protection cut out is not the cause. The units return air Temp is controlled by the controller, changed this for another controller to make sure it's not the sensor but problem still occurs.
Possible that it is the evaporator coil thermistor that is playing up or maybe the FCU PCB?
Attended site again today for another matter so checked on the system again, unit is now running well again today. Studio is down to temp, unit is running as it should.
Obviously an intermittent fault, thinking of replacing the FCU PCB and Evap Thermister.