paul_h
27-02-2008, 05:29 AM
I've got a ducted unit here that's just switching off (normally with usual CF run on), showing no faults, just cutting out @26C when the setpoint is 18C.
So it cuts out after 5-10min. Does the same thing when indoor unit put into test mode too, and doesn't come back on.
When the unit has cycled itself off, I put the outdoor unit onto forced test mode and the unit started up again, so it doesn't seem like the outdoor unit is dead, it's just getting the shutdown command I think.
Indoor unit model is a CS-80E91ER, I have nothing in this unit, but the PCBs and layout is exactly the same as the cs24bd1p.
Going by the bd1p manual, the air thermistor should be 16K ohm resistance at 30c, and this unit had a 14.5k ohm reading after removing the covers, so that seems OK. (ceiling space temp was 36C).
So basically while checking the a/c, it starts ok, cuts out without error, doesn't restart (even though thermistor reading 14.5K ohm) Also cuts out on test mode (which thermistor shouldn't effect I thought)
Could be wall controller, indoor PCB controller, just be air thermistor, or even outdoor PCB controller, any ideas on how to narrow it down?
BTW, sp480 kpa, hp 1700kpa, suction temp 2C, discharge temp 66C, liquid temp 30C. I didn't get the air on off/s because it kept cutting out. I spent most of the time checking indoor airflow, ie filter, r/a duct, good fan flow, coil condition, thermisitor mounting position, dampers and outlet ducting. So everything seems OK except for the control side of things.
edit: after reading some more I found two possible causes:
1)
After running for 9 min, the outdoor unit will cut out and no errors displayed if the outdoor pipe temp is below 12C.
2)
After running for 9 min, the outdoor unit will cut out and no errors displayed if the indoor pipe temp is below 2C.
The outdoor pipe temp controls the condenser fan speed, and if that was reading below 12C, the cf would have been running at low/super low speed. To me it seemed to be running on high speed, I didn't check the oudoor thermistors though :(
Indoor pipe temp is something I didn't check either, coil wasn't icing up though.
So it cuts out after 5-10min. Does the same thing when indoor unit put into test mode too, and doesn't come back on.
When the unit has cycled itself off, I put the outdoor unit onto forced test mode and the unit started up again, so it doesn't seem like the outdoor unit is dead, it's just getting the shutdown command I think.
Indoor unit model is a CS-80E91ER, I have nothing in this unit, but the PCBs and layout is exactly the same as the cs24bd1p.
Going by the bd1p manual, the air thermistor should be 16K ohm resistance at 30c, and this unit had a 14.5k ohm reading after removing the covers, so that seems OK. (ceiling space temp was 36C).
So basically while checking the a/c, it starts ok, cuts out without error, doesn't restart (even though thermistor reading 14.5K ohm) Also cuts out on test mode (which thermistor shouldn't effect I thought)
Could be wall controller, indoor PCB controller, just be air thermistor, or even outdoor PCB controller, any ideas on how to narrow it down?
BTW, sp480 kpa, hp 1700kpa, suction temp 2C, discharge temp 66C, liquid temp 30C. I didn't get the air on off/s because it kept cutting out. I spent most of the time checking indoor airflow, ie filter, r/a duct, good fan flow, coil condition, thermisitor mounting position, dampers and outlet ducting. So everything seems OK except for the control side of things.
edit: after reading some more I found two possible causes:
1)
After running for 9 min, the outdoor unit will cut out and no errors displayed if the outdoor pipe temp is below 12C.
2)
After running for 9 min, the outdoor unit will cut out and no errors displayed if the indoor pipe temp is below 2C.
The outdoor pipe temp controls the condenser fan speed, and if that was reading below 12C, the cf would have been running at low/super low speed. To me it seemed to be running on high speed, I didn't check the oudoor thermistors though :(
Indoor pipe temp is something I didn't check either, coil wasn't icing up though.