Airwell YUDE024, Service Manual

Page: 34 / 72

CONTROL SYSTEM
11-2 SM YUDE 2-A.1 GB
2. I control
If the operating frequency is not change more than a certain fixed time, adjust the frequency up
and down according to the
ΔD
value.
Obtaining the fixed
ΔD
value
When the
ΔD
value is small- decrease the frequency
When the
ΔD
value is large- increase the frequency
3. Frequency management when other controls are functioning
When frequency is drooping;
Frequency management is carried out only when the frequency droops.
For limiting lower limit
Frequency management is carried out only when the frequency rises.
4. Maximum and minimum limits of frequency by PI control
The frequency upper and lower limits are set depending on indoor unit.
When low noise commands come from the indoor unit or when outdoor unit low noise or quiet
commands come from indoor unit, the upper limit frequency must be lowered than the usual setting.
11.1.3.1 Frequency range
The compressor frequency limitation is set by the following table
Mode
Minimum Frequency(MinFreq)
YUDE024 YUDE030 YUDE036 YUDE036T
Cooling 15 15 15 15
Heating 15 15
15 5
The maximum allowed frequency is extracted from the following:
Mode
ODU
IDU
Maximum Frequency(MaxFreq)
YUDE024 YUDE030 YUDE036 YUDE036T
Cooling
DBDE
85 85 80 80
CADE
85 85 80 80
FADE
85 85 80 80
Heating
DBDE
85 85 80 80
CADE
85 85 80 80
FADE
85 85 80 80
11.1.3.2 Frequency Changes Control
Frequency change rate is 1 Hz/sec.
11.1.3.3 Minimum On and Off Time
Prohibit turning ON the compressor for 3 minutes after turning it off.(except during deicing
protection)