Airwell XLM12RCA, Service & Installation Manual

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CONTROL LOGIC DESCRIPTION, Cont.
PROTECTION MODES AND DELAYS.
1). OUTDOOR COIL HIGH-TEMP PROTECTION IN COOLING MODE. When the outdoor
coil temperature (OCT) is >61°C the indoor fan slows to low speed. When OCT increases to >66°C
compressor cycles off and outdoor fan is forced on. When OCT drops back to <55°C the indoor fan
is restored to normal and when OCT drops to <52°C the
compressor and outdoor fan resume normal
operation. The operation LED flashes during this protection mode. See more detail Page 22.
2). INDOOR COIL LOW-TEMP PROTECTION IN COOLING MODE. After 5 mins of
compressor operation and the indoor coil temperature (ICT) is below -3°C for a duration of 1 min the
compressor and the outdoor fan cycle off. When ICT increases to +7°C the compressor and outdoor
fan resume normal operation.
3). INDOOR COIL HIGH-TEMP PROTECTION IN HEATING MODE. When the indoor coil
temperature (ICT) is >61°C the outdoor fan turns off. When ICT increases to >66°C for 10 secs the
compressor cycles off. When ICT drops back to <55°C the outdoor fan turns on and when ICT drops
to <52°C the
compressor resumes normal operation. See more detail Page 22.
4). Compressor Minimum Run Time.
M
inimum run time on compressor is 5 mins & minimum off
time delay is 3 mins.
5). Fan Speed Change Delay. There is a 3 min delay when increasing the indoor fan speed, but no
delay on decreasing fan speed, to avoid the fan speeds changing frequently.
6). Relay Delay. If all function relays would be required to start together there is a 0.5 sec delay
between each relay activation.
7). Heat to Cool Delay. When switching from heating to cooling and visa versa modes the compressor
start is delayed by the 3 minutes minimum off time & also by the R/V 2 min delay.
UNIT INDICATOR DIAGNOSTICS.
Power/Operating LED Flashes, indicating fault as per table below.
THERMISTOR FAULT STANDBY LED DIAGNOSIS
Return Air Thermistor Fault. 1 Flash.
Indoor Coil Thermistor Fault. 2 Flashes.
Outdoor Coil Thermistor Fault. 3 Flashes.
Indoor Fan Motor Fault. 4 Flashes.
Operation LED Flashes Continuously During:-
1).
OCT High Pressure Protection Mode.
2). De-icing in heating mode.
DIAGNOSTIC LOGIC
1).
When microprocessor detects one or more of RT, ICT and OCT sensors is below -40°C (open
circuit) or over 85°C (short circuit) the sensor is considered to be faulty as indicated in the above
table, but the air conditioner operates as per note 2 below, using a default value for the faulty sensor.
2). When a faulty sensor is detected in Cooling or Heating mode, compressor cycles on for 20 mins and
cycles off for 5 mins, and runs continuously cycle by cycle. In Dehumidification mode, compressor
cycles on for 10 mins and cycles off for 6 mins.
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