Service manual
12-3
CONTROL SYSTEM
SM SX DCI 1-A.3 GB
12.1.5.2 Compressor starting control for DCI72/80
Step 1
Whenever the compressor starts up, after it has been off for more than 45 minutes, the compressor
frequency cannot go below Step1RPS for 3 continuous minutes (this rule comes to ensure oil return
to the compressor).
Step 2
The compressor speed cannot go above Step2RPS once after each compressor start up for 3
continuous minutes (this rule comes to prevent oil exit from the compressor after its start up).
Step 3
The speed cannot go higher than Step3RPS unless it was operating for more than 1 continuous
minutes between Step3RPS – 5 and Step3RPS .
After passing above Step3RPS, this rule is re-applied when passing below Step3RPS-5.
12.1.6 Minimum On and Off Time
3 minutes
12.1.7 Indoor Fan Control
8 Indoor fan speeds are determined for each model. 4 speeds for cool/dry/fan modes and 4 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.
12.1.7.1 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.
12.1.8 Outdoor Fan Control
12.1.8.1 Outdoor Fan Control for DCI50/60
7 outdoor fan speeds are determined for each model. 3 speeds for cool and dry modes, and 3
speeds for heat mode, and a very low speed.
Outdoor fan speed is a function of compressor frequency and outdoor air temperature (OAT).
4 routines for fan control are determined. The control routine selection depends on operation mode,
compressor speed, outdoor air temperature (OAT) and heat sink temperature (HST).
Routine Conditions
A
Heating with OAT < 15°C
or
Cooling with OAT > 20°C,
or
Faulty OAT
B Cooling with 20°C > OAT > 7°C
C Cooling with 7°C > OAT
D Heating with OAT > 15°C
CONTENT