Haier H2SM-(9+12)HEK03/R2 Service Manual page 20

Conditions for ending defrosting: It will restore to the heating operation from the defrosting
operation as long as any of the following conditions is met. The temperatures on both outdoor heat
exchangers are above 7 degrees for consecutive 80 seconds.
The temperatures on both outdoor heat exchangers are above 5 degrees for consecutive 12
seconds.
The defrosting operation has lasted 9 minutes.
The starting conditions and control process for the double-unit are same as that for single-unit
defrosting, the only difference is that the activation of compressor B lags that of compressor A.
5.2.11 Alarming operation
When the outdoor temperature sensor short-circuited or disconnected, the outdoor fan always
operates at the medium speed and will restore automatically after the sensor comes to normal.
When the temperature sensors on the pipes A and B short-circuited or disconnected, the double
unit will not carry out defrosting operation. During heating, this signal is sent to the indoor unit, but no
sending for other operating conditions. When sent to the indoor unit, the whole unit stops. The signal is
sent to the indoor unit which coil is operating abnormally, and the corresponding indoor unit indicates
trouble.
When the temperature sensor short-circuited or disconnected or the current transformer fails, the
indoor unit that operates abnormally, and the corresponding indoor unit indicates trouble.
H2SM-(9+12)HEK03/R2
18
Funcitions and Control
Domestic Air Conditioner