Indoor Fan Control; Outdoor Fan Control - Electra DELTA 22 Service Manual

11.4

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.
11.4.1 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
•
Room temperature > 22 for cooling, or < 25 for heating.
11.5 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.
11.6

Outdoor Fan Control

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, and outdoor air temperature (OAT) and heat sink
temperature (HST).
Routine
A
B
C
D
Compressor Frequency (CF)
CF = 0
OFLowFreq
10 ≤ CF <
OFLowFreq
≤ CF <
OFMedFreq
When compressor is switched to OFF and the heat sink temperature is above 55 degrees,
the outdoor fan will remain ON in low speed for up to 3 minutes.
SM DUO38 1-E.1 GB
Heating with OAT < 15
Cooling with OAT > 20
Cooling with 20
Cooling with 7
Heating with OAT > 15
Routine A Routine B Routine C
OFF
Low
OFMedFreq
Medium
High
≤ CF
CONTENT
Conditions
0
C
or
0
C, or HST > 50
or
Faulty OAT
0 0
C > OAT > 7 C
0
C > OAT
0
C
Outdoor Fan Speed
OFF
Low Very Low
Low Very Low
Low
CONTROL SYSTEM
degrees.
0
C
Routine D
OFF OFF
Low
Low
Low Medium
11-3