Haier AB122ACERA Service Manual - Page 60

Commercial Air Conditioner 10) Communication failure between outdoor PCB and module outdoor indicator flashes 22 times Model: AU122AEERA AB122ACERA AC122ACERA AD122ALERA no compressor not start up, outdoor alarms, check if there is other failure yes no check if the wiring between outdoor PCB and module is correct yes replace PCB eliminate other failures adjust wiring no if problem is solved replace module 11) Outdoor low pressure abnormal Alarm condition: outdoor system pressure is lower than 0.05MPa outdoor indicator flashes 24 times measure actual pressure by a pressure gauge to adjust the output failure no replace pressure switch yes low pressure abnormal no check if high pressure is low,too check if piping is blocked yes Lack of refrigerant, charge additional refrigerant and check if piping leaks, if yes, replace piping yes dredge piping (12) 4-way valve reversing failure, systerm lack of refrigerant or discharging side dirty and blocked Alarm condition: alarm and stop the unit when Td-Tci=25 and lasts for 1 minute after the compressor has started for 10 minutes in cooling mode, confirm the failure if it occurs 3 times in 1 hour outdoor failure lamp indicates 29 yes check if outdoor pressure is normal yes no refrigerant charging amount is not appropriate, recharging or remove some refrigerant check if indoor evaporator or outdoot condenser is too dirty yes clean indoor/outdoor heat exchanger 60