Haier AB122ACERA Service Manual - Page 39

Commercial Air Conditioner Model: AU122AEERA AB122ACERA AC122ACERA AD122ALERA The compressor will stop and alarm if current exceed 11A for 3 seconds contineously during compressor startup, the compressor can re-start up after 3 minutes. but the compressor will stop and alarm and confirm the failure if it stop abnormally 3 times in 60 minutes, the system will work continued after been power-off. Over current reducing frequency(FQY) protection When current exceed (B)A, the compressor will reduce FQY at 1HZ/S, if current is less than (B)A and more than (B-1)A, stop reducing FOY and then rise FQY at 1HZ/10S, when current is less than (B-A)A, reaume to the target FQY. (B is setted in the EEPROM) Compressor power protection 1) In dry and cooling mode, when compressor power over (a)W, the compressor will reduce FQY 1HZ/S, if compressor power over (b)W, the compressor will reduce FQY 0.1HZ/S, when compressor power over (c)W, rise the compressor FQY is forbidden, when compressor power over (d)W, the compressor will rise FQY 0.1HZ/S. 2) In heating mode, when compressor power over (a1)W, the compressor will reduce FQY 1HZ/S, if compressor power over (b1)W, the compressor will reduce FQY 0.1HZ/S, when compressor power over (c1)W, rise the compressor FQY is forbidden, when compressor power over (d1)W, the compressor will rise FQY 0.1HZ/S. Remark: a, b, c, d and a1, b1,c1,d1 are written in EEPROM, can be adjusted according to different system. 1.10.5 High, low pressure protection High pressure protection: high pressure switch will not detect when in standby, detect after compressor has started for 3 minutes. Low pressure protection: low pressure switch will detect after compressor has started for 3 minutes, and will shield during defrost or 6 minutes after defrost. 1.10.6 Sensor management: the detect time for sensor short-circuit or open-circuit is 4.5s, 3 minutes is needed for resume if failure is detected, the unit will work normally when the failure is cancelled. Discharge temp. sensor will not detect if it short-circuit or open-circuit, detect when compressor has started for 3 minutes. When the AD value of all sensor is less than 3, regard as the outdoor temp. too low and all sensor failtures will not alarm. Outdoor add high temp. protection Te 62℃ quick reduce FQY 1HZ/S, when Te>=70℃, quick reduce FQY 1HZ/S, and stop the unit if it lasts for 10 senconds 59℃ 55℃ remaining slow reduce FQY 1HZ/10S 1.10.7 Indoor heat exchanger anti-freezed protection Anti-freezed in cooling mode 39