Airwell CAF012, Service Manual

Page: 105 / 171

CONTROL SYSTEM
SM YIF 2-A.1 GB
12-5
12.3 Protections
12.3.1 Indoor Coil Defrost Protection
When the unit has been running for refrigeration or dehumidification for a period
and the ICT< -2 , the unit will repo
℃ rt a fault and stops the compressor and the
utdoor unit. The unit will begin to operate after ICT ≥ 10 and the ℃ compressor
nit begins defrosting. If an auxiliary heater is available, it must be stopped firstly, and
fan, the outdoor fan and the compressor will run
pleted. In such case, the
mpressor is running compulsively, and
conditions.
ompressor is started, if CTT>= 130 degree for continuous 30 seconds, E4 will be
orted for successive three
mote control signals except for button ON/OFF are
powered off and on, or failure should be
unit is started or at standby (detection will begin 3 minutes after the compressor is started
rted faults within 30 minutes. The third
atically.
12.3.6 Compressor over load Protection
o
will run again after 3 minutes stop.
12.3.2 Deicing Protection
Defrosting start conditions:
After the heating operation runs for an accumulated period of 44 minutes and the compressor
continues to operate for 4 mins and 50 seconds, and a one-minute duration of OCT
.
≤ -5
℃
is
detected, the u
after 10 seconds, the four-way valve, the indoor
compulsively.
Defrosting completion conditions:
When defrosting runs 10 minutes or OCT
≥ 10
℃
, defrosting will be com
four-way valve is running, the outdoor fan is running, the co
the indoor fan operates according to anti cold prevention
12.3.3 Compressor
over Heating Protection
After the c
displayed, all loads (except for the four way valve) will be shut off, the compressor will stop for 3
minutes.
The complete system will restart after CTT<90 degree. If such fault is rep
times, the protection can not be restored itself.
12.3.4 Compressor
high pressure Protection
When high pressure protection is detected for continuous 3 seconds, all loads are shut off (except
for the four way valve), all buttons and re
shielded. It cannot recover automatically, the unit should be
removed after power supply is restored.
12.3.5 Compressor low pressure Protection
When the
up) and detected breakdown of the low pressure switch for continuous 30 seconds, a fault is
reported.
The unit can be recovering automatically after the first 2 repo
reported fault and so on can not be recovered autom