Service manual

11-3
CONTROL SYSTEM
SM HADDCI 1-A.2 GB
11.1.3.5 Minimum On and Off Time
3 minutes.
11.1.4 Indoor Fan Control
10 Indoor fan speeds are determined for each model. 5 speeds for cool/dry/fan modes and 5 speeds
for heat mode.
When user sets the indoor fan speed to a fixed speed (Low/ Medium/ High), unit will operate constantly
at set speed.
When Auto Fan is selected, indoor unit controller can operate in all speeds. The actual speed is set
according to the cool/heat load.
11.1.4.1 Turbo Speed
The Turbo speed is activated during the first 30 minutes of unit operation when auto fan speed is
selected and under the following conditions:
 Difference between set point and actual room temperature is bigger then 3 degrees.
 Room temperature > 22 for cooling, or < 25 for heating.
11.1.5 Heating Element Control
Heating element can be started if LOAD > 0.8 * MaximumNLOAD AND Indoor Coil temperature
< 45.
The heating element will be stopped when LOAD < 0.5 * MaximumNLOAD OR if Indoor Coil
temperature > 50.
11.1.6 Outdoor Fan Control
11.1.6.1 The following are the speeds types (General Rules):
1. For S/W 37V3 and lower ( For 453031000R Controller)
The OFAN motor is an AC type that operates with 2 speeds (Low/High), controlled by
.Relays
OFAN speed depends on the compressor Target Frequency, and is set according to the following
table and graphs below and OFAN can change its Speed only if it has been working in the current
speed for at least 35 seconds:
OFAN Speed
Compressor
Target Frequency
Normal cases
State A at cool / Heat
State B
at cool
State C
at cool
OAT>15
o
C
at heat
Freq=0 OFF OFF OFF OFF
10 ≤ Freq < OFLowFreq Low Low Low Low
OFLowFreq ≤ Freq< OFMedFreq High Low Low Low
OFMedFreq≤ Freq High Low Low High
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